category high benzene naphthas december 2010

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U.S. Environmental Protection Agency December, 2010 Hazard Characterization Document 1 SCREENING-LEVEL HAZARD CHARACTERIZATION High Benzene Naphthas Category SPONSORED CHEMICALS SUBCATEGORY I: PYGAS Pyrolysis Gasoline (Dripolene) No CASRN Recovered Oil from Wastewater Treatment CASRN 68956-70-7 SUBCATEGORY II: HIGH BENZENE NAPHTHAS Pyrolysis C6 Fraction No CASRN Pyrolysis C5 – C6 Fraction No CASRN Pyrolysis C6 – C8 Fraction No CASRN Hydrotreated C6 Fraction No CASRN Hydrotreated C6 C7 Fraction No CASRN Hydrotreated C6 – C8 Fraction CASRN 68410-97-9 Aromatic Extract from Benzene Extraction CASRN 64741-99-7 SUBCATEGORY III: QUENCH/COMPRESSOR OIL Quench Loop Pyrolysis Oil and Compressor Oil CASRN 69013-21-4 SUPPORTING CHEMICALS Isoprene CASRN 78-79-5 n-Pentane CASRN 109-66-0 1,3-Cyclopentadiene CASRN 542-92-7 Isohexane CASRN 107-83-5 n-Hexane CASRN 110-54-3 Methylcyclopentane CASRN 96-37-7 Benzene CASRN 71-43-2 Toluene CASRN 108-88-3 m-Xylene CASRN 108-38-3 Xylene (mixed isomers) CASRN 1330-20-7 Styrene CASRN 100-42-5 Dicyclopentadiene CASRN 77-73-6 Naphthalene CASRN 91-20-3

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Page 1: Category High Benzene Naphthas December 2010

U.S. Environmental Protection Agency December, 2010 Hazard Characterization Document

1

SCREENING-LEVEL HAZARD CHARACTERIZATION

High Benzene Naphthas Category

SPONSORED CHEMICALS

SUBCATEGORY I: PYGAS Pyrolysis Gasoline (Dripolene) No CASRN Recovered Oil from Wastewater Treatment CASRN 68956-70-7

SUBCATEGORY II: HIGH BENZENE NAPHTHAS Pyrolysis C6 Fraction No CASRN Pyrolysis C5 – C6 Fraction No CASRN Pyrolysis C6 – C8 Fraction No CASRN Hydrotreated C6 Fraction No CASRN Hydrotreated C6 – C7 Fraction No CASRN Hydrotreated C6 – C8 Fraction CASRN 68410-97-9 Aromatic Extract from Benzene Extraction CASRN 64741-99-7

SUBCATEGORY III: QUENCH/COMPRESSOR OIL

Quench Loop Pyrolysis Oil and Compressor Oil CASRN 69013-21-4

SUPPORTING CHEMICALS Isoprene CASRN 78-79-5 n-Pentane CASRN 109-66-0 1,3-Cyclopentadiene CASRN 542-92-7 Isohexane CASRN 107-83-5 n-Hexane CASRN 110-54-3 Methylcyclopentane CASRN 96-37-7 Benzene CASRN 71-43-2 Toluene CASRN 108-88-3 m-Xylene CASRN 108-38-3 Xylene (mixed isomers) CASRN 1330-20-7 Styrene CASRN 100-42-5 Dicyclopentadiene CASRN 77-73-6 Naphthalene CASRN 91-20-3

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The High Production Volume (HPV) Challenge Program1 was conceived as a voluntary initiative aimed at developing and making publicly available screening-level health and environmental effects information on chemicals manufactured in or imported into the United States in quantities greater than one million pounds per year. In the Challenge Program, producers and importers of HPV chemicals voluntarily sponsored chemicals; sponsorship entailed the identification and initial assessment of the adequacy of existing toxicity data/information, conducting new testing if adequate data did not exist, and making both new and existing data and information available to the public. Each complete data submission contains data on 18 internationally agreed to “SIDS” (Screening Information Data Set2) endpoints that are screening-level indicators of potential hazards (toxicity) for humans or the environment. The Environmental Protection Agency’s Office of Pollution Prevention and Toxics (OPPT) is evaluating the data submitted in the HPV Challenge Program on approximately 1400 sponsored chemicals by developing hazard characterizations (HCs). These HCs consist of an evaluation of the quality and completeness of the data set provided in the Challenge Program submissions. They are not intended to be definitive statements regarding the possibility of unreasonable risk of injury to health or the environment. The evaluation is performed according to established EPA guidance,3 and is based primarily on hazard data provided by sponsors; however, in preparing the hazard characterization, EPA considered its own comments and public comments on the original submission as well as the sponsor’s responses to comments and revisions made to the submission. In order to determine whether any new hazard information was developed since the time of the HPV submission, a search of the following databases was made from one year prior to the date of the HPV Challenge submission to the present: (ChemID to locate available data sources including Medline/PubMed, Toxline, HSDB, IRIS, NTP, ATSDR, IARC, EXTOXNET, EPA SRS, etc.), STN/CAS online databases (Registry file for locators, ChemAbs for toxicology data, RTECS, Merck, etc.) and Science Direct. OPPT’s focus on these specific sources is based on their being of high quality, highly relevant to hazard characterization, and publicly available. OPPT does not develop HCs for those HPV chemicals which have already been assessed internationally through the HPV program of the Organization for Economic Cooperation and Development (OECD) and for which Screening Initial Data Set (SIDS) Initial Assessment Reports (SIAR) and SIDS Initial Assessment Profiles (SIAP) are available. These documents are presented in an international forum that involves review and endorsement by governmental authorities around the world. OPPT is an active participant in these meetings and accepts these documents as reliable screening-level hazard assessments. These hazard characterizations are technical documents intended to inform subsequent decisions and actions by OPPT. Accordingly, the documents are not written with the goal of informing the general public. However, they do provide a vehicle for public access to a concise assessment of the raw technical data on HPV chemicals and provide information previously not readily available to the public.

1 U.S. EPA. High Production Volume (HPV) Challenge Program; http://www.epa.gov/chemrtk/index.htm. 2 U.S. EPA. HPV Challenge Program – Information Sources; http://www.epa.gov/chemrtk/pubs/general/guidocs.htm. 3 U.S. EPA. Risk Assessment Guidelines; http://cfpub.epa.gov/ncea/raf/rafguid.cfm.

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Chemical Abstract Service

Registry Number (CASRN)

Sponsored Chemicals See Table 1

Supporting Chemicals

See Table 4

Chemical Abstract Index Name

Sponsored Chemicals See Table 1

Supporting Chemicals

See Table 4

Structural Formula

Sponsored Chemicals See Appendix

Supporting Chemicals

See Appendix

Summary

The high benzene naphthas category is composed of 10 ethylene-manufacturing streams that share a common origin in the ethylene process and share similar compositions. The category consists of 19 CAS numbers, each of which represents at least one of the category production streams. In some cases, a single CAS number is a component in more than one stream (see Table 1). The sponsor has chosen 12 representative chemicals that are components of the sponsored petroleum streams to characterize their physicochemical and fate properties. The members of the high benzene naphthas category are liquids with moderate to high water solubility and high vapor pressure. The members of the high benzene naphthas category are expected to possess moderate mobility in soil. Volatilization is expected to be high based on the Henry’s Law constants of these substances. The rate of hydrolysis is expected to be negligible since the substances in this category do not possess functional groups that hydrolyze under environmental conditions. The rate of atmospheric photooxidation is considered slow to rapid. Most of the members of the high benzene naphthas category are expected to possess low persistence (P1). The pyrolysis gasoline stream, which contains 20% dicyclopentadiene, and the quench loop pyrolysis oil and compressor oil stream, which contains 38.8–50% “C11+ compounds”, are expected to possess moderate persistence (P2). The members of the high benzene naphthas category are expected to possess low bioaccumulation potential (B1).

Human Health Hazard For the human health endpoints, the ten streams in the high benzene naphthas category have been divided into three subcategories based on similarities and differences in the individual stream components. This division of the streams was based on the existence and concentration of 12 key components in each stream and is explained more fully in the Category Justification and Justification for Supporting Chemical sections of this document where the use of read-across is also described (see Table 4).

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Subcategory I: Pygas The acute oral and dermal toxicity of pyrolysis gasoline (No CASRN) is low in rats and rabbits, respectively. All other human health endpoints are filled using supporting chemical (stream component) data. Available information on repeated-dose toxicity for the supporting chemicals reveals a variety of effects from both inhalation and oral exposures. The range in benchmark dose/concentration (BMDL or BMCL) and NOAECs are from 2.6 – 61 ppm and 12 - 6600 ppm/day for inhalation and from a single BMDL of 238 mg/kg/day and NOAELs of from 4-500 mg/kg/day for oral exposures. The inhalation BMCL is based on blood effects in a human epidemiology study with CASRN 71-43-2 in China; and the 61 ppm value is based on decreases in motor conduction velocity measurements in animals for CASRN 110-54-3. The low NOAEC is based on deficits in neurological function based on a meta-analysis of 10 human occupational studies for CASRN 108-88-3 (average exposures where effects were observed was estimated to be 14 ppm). The high NOAEC value is based on no effects seen at this highest dose in a repeated-dose study with CASRN 109-66-0. However, there is a LOAEC lower than the lowest NOAEC or BMCL value; the ATSDR MRL (minimum risk level) for CASRN 91-20-3 estimated a LOAEC of 0.2 ppm for humans based on non-neoplastic and neoplastic effects in rats (restricted to the nose and lungs) in a two-year cancer study in which the lowest concentration used was 10 ppm. The oral BMDL is based on kidney effects in a 90-day animal study with CASRN 108-88-3. The low end of the range of oral NOAEL values is based on systemic effects observed in a combined repeated-dose/reproductive/developmental test with CASRN 77-73-6 in which rats experienced kidney and adrenal gland effects at 20 mg/kg/day. At the high end, kidney effects and mortality were observed at 2000 mg/kg/day in a 28-day study with CASRN 96-37-7. No effects on the reproductive organs were observed in oral repeated-dose studies in rats with CASRNs 109-66-0, 100-42-5 and 91-20-3; however, CASRN 78-79-5 showed testicular effects and changes in estrus cyclicity after repeated oral dosing in mice. CASRN 110-54-3 caused testicular damage in animals at high (>4000 mg/kg/day) oral doses. In a combined oral repeated-dose/reproductive/developmental toxicity screening test in rats with CASRN 77-73-6, no adverse effects on reproductive parameters were observed; the NOAEL for reproductive toxicity is 100 mg/kg/day (highest dose tested). Repeated inhalation exposures in mice with CASRN 71-43-2 showed effects on the reproductive organs in both sexes. In an inhalation reproductive toxicity screening test and a two-generation reproductive toxicity study in rats, CASRN 108-88-3 significantly decreased the sperm count, epididymal weight and pup weights at 7.5 mg/L/day; the NOAEC for reproductive toxicity is 2.3 mg/L/day. In inhalation reproductive toxicity studies in rats, CASRNs 1330-20-7 (one-generation study) and 100-42-5 (two-generation study) showed no treatment-related effects on reproductive parameters; the NOAEC for reproductive toxicity is 2 mg/L/day (highest concentration tested). For developmental toxicity, a BMCL of 787 ppm was determined for CASRN 110-54-3 (based on fetal malformations in the developmental toxicity study). In a prenatal oral developmental toxicity study in rats, CASRN 109-66-0 showed no maternal or developmental effects; the NOAEL for maternal developmental toxicity is 1000 mg/kg-day (highest dose tested). In the combined oral repeated-dose/reproductive/developmental toxicity screening test in rats with CASRN 77-73-6, no abnormal findings attributed to the test substance were found for external features, clinical signs or on necropsy of offspring; the NOAEL for maternal toxicity is 20 mg/kg-day (reduced body weight at 100 mg/kg-day) and for developmental toxicity is 100

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mg/kg-day (highest dose tested). In prenatal inhalation developmental toxicity studies in rats and mice, CASRN 7879-5 did not produce any maternal or developmental toxicity in rats following exposure to concentrations as high as 19.5 mg/L/day; the NOAEC for maternal/developmental toxicity is 19.5 mg/L/day. In mice, maternal weight gain and uterine weight were significantly reduced at 19.5 mg/L/day. Significant reductions in fetal bodyweight were observed at 1 mg/L/day in female fetuses (lowest concentration tested); the NOAEC for maternal toxicity is 3.9 mg/L/day and the NOAEC is not established for developmental toxicity. In the two-generation inhalation reproductive toxicity study in rats with CASRN 108-88-3, developmental toxicity included decreased fetal growth and pup weight accompanied by delayed ossification in F1 and F2 offspring at 3.8 mg/L/day; the NOAEC for developmental toxicity is 2.3 mg/L/day and the NOAEC for maternal toxicity is 4.3 mg/L/day (highest concentration tested). In the two-generation inhalation reproductive toxicity study in rats, CASRN 100-42-5 showed decreased body weights and decreased fetal body weights and delayed development at 0.64 mg/L/day; the NOAEC for maternal and developmental toxicity is 0.2 mg/L/day. In a prenatal inhalation developmental toxicity study in rats, CASRN 1330-20-7 decreased body weight, weight gain and food consumption in dams at 4.4 mg/L/day and decreased fetal body weight at 2.2 mg/L/day; the NOAEC for maternal toxicity is 2.0 mg/L/day and the NOAEC for developmental toxicity is 0.44 mg/L/day. In an inhalation prenatal developmental toxicity study in mice, CASRN 71-43-2 showed effects on the hematopoietic system in offspring at 0.064 mg/L/day; the NOAECs for maternal and developmental toxicity are 0.064 mg/L/day (highest concentration tested) and 0.032 mg/L/day, respectively. Of the tested supporting chemicals, only CASRN 71-43-2 was mutagenic in bacteria and mammalian cells in vitro. CASRNs 78-79-5, 110-54-3, 108-88-3, 1330-20-7 and 77-73-6 did not induce chromosomal aberrations in vitro; CASRN 109-66-0 showed equivocal results and CASRNs 71-43-2, 100-42-5 and 91-20-3 were positive. CASRNs 109-66-0, 108-88-3, 1330-20-7, 100-42-5 and 91-20-3 did not induce chromosomal aberrations in vivo; CASRNs 78-79-5, 110-54-3 and 71-43-2 were positive. Some of the supporting chemicals increased the incidence of tumors (CASRNs 78-79-5, 71-43-2, 100-42-5 and 91-20-3) while CASRNs 108-88-3 and 1330-20-7 did not. The supporting chemicals are generally irritating to the skin and eyes but are not skin sensitizers. CASRNs 110-54-3, 108-88-3, 1330-20-7 and 100-42-5 are neurotoxic. No data gaps were identified under the HPV Challenge Program. Subcategory II: High Benzene Naphthas The supporting chemical data from subcategory I (excepting data for CASRN 91-20-3) can also be used to address the human health endpoints for subcategory II. Please see summary of available data in subcategory I above. The acute oral and inhalation toxicity of CASRN 68410-97-9 in rats is low. CASRN 68410-97-9 was not mutagenic in bacteria in vitro and did not induce mouse micronuclei in vivo. CASRN 68410-97-9 did not induce unscheduled DNA synthesis. No data gaps were identified under the HPV Challenge Program.

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Subcategory III: Quench/Compressor Oil There are no human health data available on the sponsored stream. The human health hazard of subcategory III is characterized by data for CASRNs 71-43-2, 108-88-3, 1330-20-7, 100-42-5, 77-73-6 and 91-20-3. Please see summary of available data for these CASRNS in subcategory I above. No data gaps were identified under the HPV Challenge Program. Hazard to the Environment No data are available for the sponsored streams. The 96-h LC50 value for fish ranges from 1 – 10 mg/L for CASRN 91-20-3, 5.4 – 26 mg/L for CASRN 108-88-3, 2.6 – 26.7 mg/L for CASRN 108-38-3, 5.3 – 15.6 mg/L for CASRN 71-43-2 and is 4.3 mg/L for CASRN 109-66-0. The 48-h EC50 value for aquatic invertebrates ranges from 0.22 – 1.96 mg/L for CASRN 91-20-3, 10 – 17.2 mg/L for CASRN 71-43-2, is 8.5 mg/L for CASRN 108-88-3, 11.5 mg/L for CASRN 108-38-3 and 2.7 mg/L for CASRN 109-66-0. The 72-h EC50 value for toxicity to aquatic plants is 0.4 mg/L for CASRN 91-20-3, 12.5 mg/L for CASRN 108-88-3, 10.7 mg/L for CASRN 109-66-0, 28 mg/L for CASRN 71-43-2 and ranges from 3.2 – 4.9 mg/L for CASRN 108-38-3. No data gaps were identified under the HPV Challenge Program.

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The sponsor, the American Chemistry Council Olefins Panel, submitted a Test Plan and Robust Summaries to EPA for high benzene naphthas dated December 12, 2001. EPA posted the submission on the ChemRTK HPV Challenge website on January 29, 2002 (http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm). EPA comments on the original submission were posted to the website on August 26, 2002. Public comments were also received and posted to the website. The sponsor provided updated/revised documents on August 7, 2003, January 12, 2004 and December 10, 2004, which were posted to the ChemRTK website on October 20, 2003, April 27, 2004 and December 22, 2004, respectively. Category Justification The sponsor stated that the high benzene naphthas category is composed of 10 ethylene-manufacturing streams that share a common origin in the ethylene process and share similar compositions. The category consists of 19 CAS numbers, each of which represents at least one of the category production streams (Table 1). The production streams consist of complex hydrocarbon reaction products; which are predominantly C5 through C11. Pyrolysis gasoline (Dripolene) is the major stream in the category and essentially all of the other nine category streams are derived from it, either as simple distillate fractions or hydrogenated distillate fractions. The streams contain large amounts of benzene, generally > 10% and averaging 55%. Pyrolysis gasoline and the distillate fractions account for 99% of category production. The remainder (the quench loop pyrolysis and compressor oil; aromatic extract from benzene extraction and the recovered oil from wastewater treatment) account for approximately 1%. The sponsor further proposed that the 10 streams in this category share a number of common constituents (or components) and that these constituents would be largely responsible for describing all the SIDS endpoints. However, these process streams are complex mixtures with some differences in their respective compositions. As noted in the sponsor’s test plan, considerable variation may occur not only between, but also within manufacturing facilities, depending on feedstock type and operating conditions. The sponsor proposed to treat the 10 streams as one category. Based on the available information on the composition of the different streams, EPA has divided the category into three subcategories for human health endpoints consisting of two, seven and one member(s), respectively (Table 2). All 10 streams are treated as one category for all other hazard endpoints. EPA agrees that there are sufficient similarities among 7/10 streams (subcategory II). Pyrolysis gasoline has many more components than the other seven streams in subcategory II (58 vs the next nearest number of 17 for the pyrolysis C6 fraction) and so warrants being separated into its own subcategory. EPA paired the recovered oil from wastewater treatment with pyrolysis gasoline (subcategory I) because it is the recovered mixture from the generation of the pyrolysis gasoline and so is assumed to represent an extract of the pyrolysis gasoline stream4. Subcategory III (quench loop pyrolysis oil and compressor oil) is different enough (i.e., lowest benzene content, high C11+ content) from the streams assigned to subcategories I or II to be considered

4 The sponsor did not provide any information on the composition of the recovered oil from wastewater treatment stream except to say: “(T)his stream can be expected to be of variable composition and made up largely of the components found in Pygas. No composition data or process specific information have been reported.” (from p. 4 in the December, 2004 Category Summary).

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separately in this analysis. (See next section – Justification for Supporting Chemicals – for a more detailed analysis).

Table 1. CASRN1 and Components of Low Benzene Naphthas Category Members

Sponsored Stream CASRN CA Index Name 68606-10-0 Gasoline, pyrolysis, debutanizer bottoms 68921-67-5 Hydrocarbons, ethylene-mfg.-by-product distillation. residues 64742-83-2 Naphtha (petroleum), light steam-cracked

64742-91-2 Distillates (petroleum), steam-cracked 67891-79-6 Distillates (petroleum), heavy aromatic 67891-80-9 Distillates (petroleum), light aromatic

68476-45-9 Hydrocarbons, C5 – 10 aromatic conc., ethylene-mfg.-by-product 68526-77-2 Aromatic hydrocarbons, ethane cracking scrubber effluent and flare drum68606-28-0 Hydrocarbons, C5 and C10-aliphatic and C6 – 8-aromatic

Pyrolysis gasoline

68955-29-3 Distillates (petroleum), light thermal cracked, debutanized aromatic 68955-29-3 Distillates (petroleum), light thermal cracked, debutanized aromatic 64742-83-2 Naphtha (petroleum), light steam-cracked

Pyrolysis C5 – C6 fraction

68956-52-5 Hydrocarbons, C4 – 8 64742-83-2 Naphtha (petroleum), light steam-cracked 68955-29-3 Distillates (petroleum), light thermal cracked, debutanized aromatic

Pyrolysis C6 fraction

68606-10-0 Gasoline, pyrolysis, debutanizer bottoms 68475-70-7 Aromatic hydrocarbons, C6 – 8, naphtha-raffinate pyrolyzate-derived. 68955-29-3 Distillates (petroleum), light thermal cracked, debutanized aromatic

64742-83-2 Naphtha (petroleum), light steam-cracked

Pyrolysis C6 – C8 fraction

68476-45-9 Hydrocarbons, C5 – 10 aromatic concentrate., ethylene-mfg.-by-product 68410-97-9 Distillates (petroleum), light distillate hydrotreating process, low-boiling Hydrotreated C6 fraction

8030-30-6 Naphtha 68410-97-9 Distillates (petroleum), light distillate hydrotreating process, low-boiling 64742-49-0 Naphtha (petroleum), hydrotreated light

64742-73-0 Naphtha (petroleum), hydrodesulfurized light

Hydrotreated C6 – C7 fraction

68955-29-3 Distillates (petroleum), light thermal cracked, debutanized arom. Hydrotreated C6 – C8 fraction

68410-97-9 Distillates (petroleum), light distillate hydrotreating process, low-boiling

Quench loop pyrolysis oil and compressor oil

69013-21-4 Fuel oil, pyrolysis

Recovered oil from wastewater treatment

68956-70-7 Petroleum products, C5 – 12, reclaimed, wastewater treatment

Aromatic extract from benzene extraction

64741-99-7 Extracts (petroleum), light naphtha solvent

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1The CAS numbers associated with the corresponding production streams are shown in the above table. In some cases, more than on CAS number is used to represent a specific stream and in other cases a single CAS number may be used to represent more than one stream. The Olefins Industry or others may use these same CAS numbers to represent substances that may, in various degrees, be dissimilar to the category streams. CAS numbers other than those shown in this table may be used to describe these streams.

Table 2. Subcategories in the High Benzene Naphthas Category

Sponsored Stream Human Health Hazard Pyrolysis Gasoline Recovered Oil from Wastewater Treatment

Subcategory I

Pyrolysis C6 Fraction Pyrolysis C6-C8 Fraction Pyrolysis C5-C6 Fraction Hydrotreated C6 Fraction Hydrotreated C6-C7 Fraction Hydrotreated C6-C8 Fraction Aromatic Extract from Benzene Extraction

Subcategory II

Quench Loop Pyrolysis Oil and Compressor Oil Subcategory III Justification for Supporting Chemicals The sponsor uses components of the high benzene naphthas streams (see Table 3 below and Table 12 in the Appendix), limited data on two sponsored streams, and limited data on a proposed similar stream (see Table 13 in the Appendix) as supporting information to assess the SIDS endpoints for the category. Table 3 presents the 12 components identified as supporting chemicals by the sponsor. Only two components are found in all 10 streams – benzene and toluene. The other ten components are found in 3-5 of the10 streams. This suggests that using the component data for read-across requires care because data on some components – with the exception of benzene and toluene – would not be applicable to streams for which they are not present (i.e., n-pentane for all of the pyrolysis fraction streams). The other consideration when evaluating components in a mixture as supporting chemicals is the amount of the component in each stream (see Table 12 in the Appendix). For example, although benzene and toluene are found in the quench loop pyrolysis oil and compressor oil stream, it is present at the lowest amount compared with the other nine streams. Also, when comparing Table 3 with Table 12, n-pentane seems to be the one component that is present only in one other stream besides pyrolysis gasoline (and the recovered oil stream), and it is present at a very small concentration (1% - hydrotreated C6-7 fraction). The use of rerun tower heads is proposed by the sponsor as a similar stream to describe the toxicology of the sponsored streams. This stream is described to be a C5 – 10 fraction of pyrolysis gasoline with the CASRN 64741-74-8. The CAS name is naphtha, petroleum, light thermal cracked and the CAS definition is: a complex combination of hydrocarbons

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Table 3: Presence of Components Identified as Supporting Chemicals in the Process Streams in the High Benzene Naphthas Category1

Subcategory I Subcategory II Subcategory

III Chemical Name

Pyrolysis Gasoline

Recovered Oil

From Wastewater Treatment

Pyrolysis C6

Fraction

Pyrolysis C6 – C8 Fraction

Pyrolysis C5 – C6 Fraction

Hydro-treated C6 Fraction

Hydro-treated C6

– C7 Fraction

Hydro-treated C6

– C8 Fraction

Aromatic Extract

from Benzene

Extraction

Quench Loop Pyrolysis Oil

and Compressor

Oil

Number of Streams in Which

Supporting Chemicals are

Present

Total # of Components2 58 (58?)3 17 13 5 7 15 5 3 13 Isoprene X (X) X X 4 n-Pentane X (X) X 3 1,3-cyclopentadiene X (X) X X 4 Isohexane X (X) X X 4 Hexane X (X) X X X 5 Methylcyclopentane X (X) X 3 Benzene X (X) X X X X X X X X 10 Toluene X (X) X X X X X X X X 10 Mixed xylenes X (X) X X X 5 Styrene X (X) X X 4 Naphthalene X (X) X 3 Dicyclopentadiene X (X) X X 4 Approx. Percentage of Total Covered by Supporting Chemicals4

>80 ? 37-93 50-100 81 ~85 >60 50-85 100 33-60

Other Major Components (%)

~ 15 (>C9) ? 30 (C6 non-aromatics)

- - - 5-20 (C6) ~5-10 (C7)

20-26 (non-aromatic

HC)

- 38-50 (>C11)

1 Taken from Appendix 2: Composition, pp.42–44 of the 2004 Category Summary by the submitter (identified as the “Revised Test Plan” under the Final Revision posted on December 22, 2004 at the following link: http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm ).  Only the 12 chemicals identified as supporting chemicals are presented. 2 This row shows the total number of components in each category stream. 3 There are no specific composition data for this stream. It is expected to contain components of pyrolysis gasoline. 4 These approximations show that – collectively - the 12 supporting chemicals represent a significant percentage of the streams in this category.

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from distillation of products from a thermal cracking process and it consists predominantly of unsaturated hydrocarbons having carbon numbers predominantly in the range of C4 through C8 and boiling in the range of approximately -10 – 130 °C). The sponsor has provided no rationale for using data from this stream to support the proposed category. This stream is minimally characterized (40% benzene, 13% toluene, 26% C5, 20% “other”). Benzene and toluene together make up about 53% of the stream, thus putting it in the same range for the top two components with many of the sponsored streams. The lack of specificity of the components present in the rest of the stream does present some uncertainty; however, EPA presents the data in this hazard characterization for information purposes. Other non-category streams that were considered similar streams by the sponsor were presented for the biodegradation and aquatic toxicity SIDS endpoints. However, EPA has used the components in the category streams for its analysis as further described below. Table 4 shows how the component data will be used in this analysis for the SIDS endpoints. As discussed in the EPA Supplementary Guidance for Conducting Health Risk Assessment of Chemical Mixtures5, when evaluating the hazard of such complex streams (either alone or in a category), there are three options to consider: (1) testing of the stream of concern; (2) testing of a toxicologically similar stream; or (3) considering the available data on stream components. In this case, all three options were used by the sponsor in their final submission.

Table 4. Supporting Information Used in High Benzene Naphthas Category CASRN

CA Index

Name Physical-Chemical

Properties / Environmental

Fate

Human Health Hazard

Hazard to the

Environment

Number of Streams in

Which CASRN found

(out of 10)

(%) of Total Stream Content

Sub category

I, II, and/or III

78-79-5 1,3-Butadiene, 2-methyl-

X (X) X 4 0.6 – 6.0 I, II

109-66-0 Pentane X (X) X X 3 1-10 I, II 542-92-7 1,3-Cyclo

pentadiene X X 4 0.1 - 20 I, II

107-83-5 Pentane, 2-methyl-

X X 4 1.3 - 20 I, II

110-54-3 Hexane X (X) X 5 0 - 15 I, II 96-37-7 Cyclopentane,

methyl-

X X 3 4.9 - 15 I, II

71-43-2 Benzene X (X) X X 10 10 - 80 I, II, III 108-88-3 Benzene,

methyl-

X (X) X X 10 0.5 - 40 I, II, III

1330-20-7 Benzene, dimethyl-

X (X) X X 5 1 - 10 I, II, III

100-42-5 Benzene, ethenyl-

X (X) X 4 1 - 15 I, II, III

5 Published in 2000 and available at: http://www.epa.gov/raf/publications/sup-guidance-hra-chem-mix.htm

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Table 4. Supporting Information Used in High Benzene Naphthas Category CASRN

CA Index

Name Physical-Chemical

Properties / Environmental

Fate

Human Health Hazard

Hazard to the

Environment

Number of Streams in

Which CASRN found

(out of 10)

(%) of Total Stream Content

Sub category

I, II, and/or III

77-73-6 4,7-Methano-1H-indene,3a,4,7,7a-tetrahydro-

X (X) X 4 1 - 20 I, II, III

91-20-3 Naphthalene X (X) X X 3 4.3 - 15 I, III Physicochemical Properties and Environmental Fate The sponsor proposed to use data for the 12 representative components to define the physicochemical property ranges and general fate and transport characteristics for the sponsored process streams. This approach is supported in most cases because these 12 chemicals accurately represent the major constituents for many of the sponsored streams. Nevertheless, some inadequacies remain that have not been addressed by the sponsor. The stream “Quench Loop Pyrolysis Oil and Compressor Oil” is likely to contain constituents that are more persistent and will partition more readily to soils than indicated by the data provided for the 12 representative compounds. The sponsor has not demonstrated that the amounts of higher molecular weight components in this stream are negligible and so the use of the 12 representative compounds is not supported for this stream for the log Kow, fugacity and biodegradation endpoints. Finally, biodegradation data summaries for several petroleum streams from other categories are provided in the test plan, but limited descriptions of these streams (p. 57 in the 2004 Category Summary) is provided and there were no robust summaries provided for them. Therefore, the similarity of these other streams to the sponsored streams in the proposed high benzene naphthas category cannot be established, and these data cannot be used to support this category. The sponsor provides only one robust summary for the biodegradation of benzene to support this endpoint, however, the biodegradation of complex process streams cannot be adequately represented by the biodegradation of a single chemical, and therefore EPA has used published data on eight of the other major components to assess the streams in this category for these endpoints. Human Health Hazard For the human health endpoints, there are limited data on two of the 10 sponsored streams (acute toxicity data for pyrolysis gasoline and hydrotreated C6-8 fraction); some data on a potentially “toxicologically similar stream” (rerun tower overheads); and citations for data on 12 components; all of which are in 3-5 sponsored streams – except for 2/12 (benzene and toluene), which are found in all 10 streams. The sponsor presented an argument for using data for all three of these scenarios but did not follow through with read-across using the data. The sponsor provided robust summaries for two of the sponsored streams (pyrolysis gasoline [Dripolene] and hydrotreated C6 – C8 stream), and one putative analogous stream (rerun tower overheads). The sponsor also proposed to use benzene as the component that determines the toxicity of all the streams for the human health endpoints. The sponsor argues that most of the other components in the sponsored streams are present at low concentrations, are of low

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expected toxicity, and that the mixtures are expected to be less toxic than the individual components. Robust summaries were not provided for any tests conducted on the components of the sponsored streams, thus not allowing the reader to compare these studies with the robust summaries submitted for the two tested sponsored streams and the putative similar stream (rerun tower overheads). EPA used available data for the pyrolysis gasoline and hydrotreated C6-8 fraction stream data on acute toxicity (both streams) and genetic toxicity data (hydrotreated C6-8 fraction only). In addition, available genetic toxicity data on the quench loop pyrolysis oil was used. For all other endpoints, component data was used and the data from which this information will be used is presented in Table 4. EPA is preparing a hazard characterization document on the low benzene naphthas category which has many similarities in approach to the low benzene naphthas category. This document will be available at: http://iaspub.epa.gov/oppthpv/hpv_hc_characterization.get_report_by_cas?doctype=2. Hazard to the Environment For ecotoxicity purposes, the supporting chemicals n-pentane (CASRN 109-66-0), benzene (CASRN 71-43-2), toluene (CASRN 108-88-3), m-xylene (CASRN 108-38-3), and naphthalene (CASRN 91-20-3) were used to describe the toxicity to aquatic organisms based on the following criteria:

(1) These chemicals encompass the carbon range for the High Benzene Naphthas Streams being described (C5-C11).

(2) The components of the High Benzene Naphthas Streams include one or more of the supporting chemicals in a given percentage (1-80%; see Appendix I)

(3) EPA determined that the additional measured data from these supporting chemicals are appropriate to help support the High Benzene Naphthas category based on its similar physico-chemical properties, environmental fate and trend in mode of toxic action (narcosis).

1. Chemical Identity 1.1 Identification and Purity Table 1 provides a listing of the category member streams. Note that some CASRNs are present in more than one stream. See Table 1 for a description of how the various streams are produced and a listing of stream components. Vinyl acetate is listed as a significant component of at least one “non-typical” example of the pyrolysis gasoline stream. Oxygenated compounds are not part of the descriptions of any of the sponsored streams and are not part of any of the CAS definitions for any of the CAS numbers associated with the proposed category. The sponsor claims that this result was an anomaly and that vinyl acetate was detected in only one stream. From the information provided in the test plan, it is unclear if there is a significant exposure potential for the vinyl acetate produced in this stream, if the stream is or was treated any differently than other Pyrolysis Gasoline streams that

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don’t contain vinyl acetate, or if the vinyl acetate was stripped from the stream before it was sent for further processing. Because each of the category members is a stream which is a complex mixture of hydrocarbons, purity is not a parameter of concern. 1.2 Physical-Chemical Properties The physical-chemical properties of the sponsored substances contained in the high benzene naphthas category are summarized in Table 5, while the physical-chemical properties of the 12 supporting chemicals are provided in Table 6. The components of the high benzene naphthas category are liquids with moderate to high water solubility and high vapor pressure.

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Table 5. Physical-Chemical Properties of the High Benzene Naphthas Category1

Property SPONSORED

CHEMICAL Pyrolysis Gasoline

(Dripolene)2,3

SPONSORED CHEMICAL Pyrolysis C5 – C6

Fraction3

SPONSORED CHEMICAL Pyrolysis

C6 Fraction3

SPONSORED CHEMICALPyrolysis C6 – C8

Fraction3

SPONSORED CHEMICAL Hydrotreated C6 Fraction3

SPONSORED CHEMICAL Hydrotreated

C6 – C7 Fraction3

SPONSORED CHEMICAL Hydrotreated

C6 – C8 Fraction6

SPONSORED CHEMICAL

Aromatic Extract from

Benzene Extraction3

SPONSORED CHEMICAL

Quench Loop Pyrolysis Oil

and Compressor

Oil7

SPONSORED CHEMICAL Recovered Oil

from Wastewater Treatment8

CASRN 68606-10-0; 68921-67-5; 64742-83-2; 64742-91-2; 67891-79-6; 67891-80-9; 68476-45-9; 68526-77-2; 68606-28-0; 68955-29-3

68955-29-3; 64742-83-2; 68956-52-5

68955-29-3; 64742-83-2; 68606-10-0

68475-70-7; 68955-29-3; 64742-83-2; 68476-45-9

68410-97-9; 8030-30-6

68410-97-9; 64742-49-0; 64742-73-0; 68955-29-3

68410-97-9 64741-99-7 69013-21-4 68956-70-7

Molecular Weight Complex mixture

Complex mixture

Complex mixture

Complex mixture

Complex mixture

Complex mixture

Complex mixture

Complex mixture

Complex mixture

Complex mixture

Physical State Liquid Liquid Liquid Liquid Liquid Liquid Liquid Liquid Liquid Liquid Melting Point <25°C (based

on physical state)

<25°C (based on physical

state)

<25°C (based on physical

state)

<25°C (based on physical

state)

<25°C (based on physical

state)

<25°C (based on physical

state)

<25°C (based on physical

state)

<25°C (based on physical

state)

<25°C (based on physical

state)

<25°C (based on physical state)

Boiling Point 40–217.9°C (measured)4

37–80°C (measured)4

34–110.6°C (measured)4

80–145°C (measured)4

63.2–80.7°C (measured)4

63.2–110.6°C (measured)4

80–139.1°C (measured)4

80–145°C (measured)4

80–244.7°C (measured)4

37–244.7°C (measured)4

Vapor Pressure 0.085–435 mm Hg at

25°C (measured)4

94.8–528 mm Hg at

25°C (measured)4

28.4–550 mm Hg at

25°C (measured)4

6.40–94.8 mm Hg at

25°C (measured)4

94.8–190 mm Hg at

25°C (measured)4

28.4–190 mm Hg at 25°C (measured)4

8.29–94.8 mm Hg at 25°C (measured)4

6.40–94.8 mm Hg at

25°C (measured)4

0.067–94.8 mm Hg

at 25°C (measured)4

0.067–528 mm Hg at 25°C (measured)4

Dissociation Constant (pKa)

Not Applicable

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Table 5. Physical-Chemical Properties of the High Benzene Naphthas Category1

Property SPONSORED

CHEMICAL Pyrolysis Gasoline

(Dripolene)2,3

SPONSORED CHEMICAL Pyrolysis C5 – C6

Fraction3

SPONSORED CHEMICAL Pyrolysis

C6 Fraction3

SPONSORED CHEMICALPyrolysis C6 – C8

Fraction3

SPONSORED CHEMICAL Hydrotreated C6 Fraction3

SPONSORED CHEMICAL Hydrotreated

C6 – C7 Fraction3

SPONSORED CHEMICAL Hydrotreated

C6 – C8 Fraction6

SPONSORED CHEMICAL

Aromatic Extract from

Benzene Extraction3

SPONSORED CHEMICAL

Quench Loop Pyrolysis Oil

and Compressor

Oil7

SPONSORED CHEMICAL Recovered Oil

from Wastewater Treatment8

Henry’s Law Constant 0.00044–0.0210 atm-

m3/mol (measured)4

0.00555–0.240 atm-

m3/mol (measured)4

0.00555–0.240 atm-

m3/mol (measured)4

0.00275–0.00718

atm-m3/mol (measured)4

0.00555–1.80 atm-m3/mol

(measured)4

0.00555–1.80 atm-m3/mol

(measured)4

0.00555–0.00718 atm-

m3/mol (measured)4

0.00275–0.00555 atm-

m3/mol (measured)4

0.000514–0.00555 atm-

m3/mol (measured)4

0.000514–1.68 atm-m3/mol

(measured)4

Water Solubility 20–1,800 mg/L at 25°C (measured)4

203–1,790 mg/L at

25°C (measured)4

203–1,800 mg/L at

25°C (measured)4

161–1,790 mg/L at

25°C (measured)4

9.5–1,790 atm-m3/mol (measured)4

9.5 to 1,790 mg/L at

25°C (measured)4

161 to 1,790 mg/L at

25°C (measured)4

310 to 1,790 mg/L

at 25°C (measured)4

25.8 to 1,790 mg/L

at 25°C (measured)4

17.9 to 1,790 mg/L at

25°C (measured)4

Log Kow 2.13–3.30 (measured)4

2.13–2.58 (measured/

estimated)4,5

2.13–2.73 (measured)4

2.13–3.20 (measured)4

2.13–3.90 (measured)4

2.13–3.90 (measured)4

2.13–3.20 (measured)4

2.13–2.95 (measured)4

2.13–3.87 (measured)4

2.13–3.87 (measured)4

1 American Chemistry Council (ACC) Olefins Panel HPV Work Group. 2004. Revised Robust Summary and Test Plan for High Benzene Naphthas Category. Available online at http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm as of September 28, 2010.

2 According to the sponsor, Dripolene and pyrolysis gasoline are synonymous. 3 Data range is based upon the compositional data provided by the sponsor in the test plan from which representative structures were derived; see the Appendix for detailed information on

structures and composition. 4 SRC. The Physical Properties Database (PHYSPROP). Syracuse, NY: Syracuse Research Corporation. Available online at http://www.syrres.com/esc/physprop.htm as of September 28,

2010. 5 U.S. EPA. 2010. Estimation Programs Interface Suite™ for Microsoft® Windows, v4.00. U.S. Environmental Protection Agency, Washington, DC, USA. Available online at http://www.epa.gov/opptintr/exposure/pubs/episuitedl.htm as of September 28, 2010. 6 The sponsored substance “Hydrotreated C6 – C8 Fraction” is tentatively considered acceptable as a High Benzene Naphtha member, although the sponsor did not fully characterize the

composition of the 20–26% “non-aromatic hydrocarbons” portion of this stream. The data range for this stream is based only on those components for which representative structures could be derived from the compositional data provided by the sponsor in the revised test plan; see the Appendix for detailed information on structures and composition.

7 The sponsor did not fully categorize the composition of the “C11+ compounds” portion of Quench Loop Pyrolysis Oil and Compressor Oil stream. The lack of characterization of this component raises the potential for polyaromatic hydrocarbons in this stream. The data range for this stream is based upon components for which representative structures could be derived from the compositional data provided by the sponsor in the revised test plan with 1-methylnaphthalene as a representative compound for the “C11+ compounds” portion of this stream; see the Appendix for detailed information on structures and composition.

8 No compositional data were provided for this stream. Data range and representative structures are based upon the CAS definition for the CAS number provided for this stream.  

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Table 6. Physical-Chemical Properties of the High Benzene Naphthas Category1

SUPPORTING CHEMICALS Property

1,3-Butadiene, 2-methyl- (Isoprene)

n-Pentane 1,3-Cyclo-pentadiene

Pentane, 2-methyl-

(Isohexane)

n-Hexane Cyclopentane, methyl-

Benzene Benzene, methyl-

(Toluene)

Benzene, 1,3-dimethyl-

(m-Xylene)

Benzene, ethenyl- (Styrene)

4,7-Methano-1H-indene, 3a,4,7,7a-

tetrahydro- (Dicyclo-

pentadiene)

Naphthalene

CASRN 78-79-5 109-66-0 542-92-7 107-83-5 110-54-3 96-37-7 71-43-2 108-88-3 108-38-3 100-42-5 77-73-6 91-20-3 Molecular Weight

68.12 72.15 66.10 86.18 86.18 84.16 78.11 92.14 106.17 104.15 132.21 128.18

Physical State Volatile liquid

Volatile liquid

Liquid Liquid Liquid Liquid Liquid Liquid Liquid Liquid Clear, colorless liquid or stable solid

at room temperature4

Solid

Melting Point -145.9°C (measured)2

-129.7°C (measured

)2

-85°C (measured)

2

-162.9 °C (measured)2

-95.3°C (measured)2

-142.5°C (measured)2

5.5°C (measured)2

-94.9°C (measured)2

-47.8°C (measured)2

-31°C (measured)2

32°C (measured)2;

33.6 °C (measured)4

80.2°C (measured)2

Boiling Point 34°C (measured)2

36°C (measured

)2

41°C (measured)

2

63.2°C (measured)2

68.7°C (measured)2

71.8°C (measured)2

80°C (measured)2

110.6°C (measured)2

139.1°C (measured)2

145°C (measured)2

170°C (measured)2

217.9°C (measured)2

Vapor Pressure 550 mm Hg at 25°C

(measured)2

514 mm Hg at 25°C

(measured)2

435 mm Hg at 25°C

(measured)2

190 mm Hg at 25°C (measured)2

151 mm Hg at 25°C

(measured)2

138 mm Hg at 25°C (measured)2

94.8 mm Hg at 25°C

(measured)2

28.4 mm Hg at 25°C

(measured)2

8.29 mm Hg at 25°C

(measured)2

6.40 mm Hg at 25°C

(measured)2

2.29 mm Hg at 25°C (measured)2;

9.8 mm Hg at 37.7°C

(measured)4

0.085 mm Hg at 25°C

(measured)2

Dissociation Constant (pKa)

Not Applicable

Henry’s Law Constant

0.00767 atm-m3/mol

(measured)2

1.25 atm-m3/mol

(measured)2

0.0210 atm-m3/mol

(measured)2

1.68 atm-m3/mol (measured)2

1.80 atm-m3/mol

(measured)2

0.363 atm-m3/mol

(measured)2

0.00555 atm-m3/mol

(measured)2

0.00664 atm-m3/mol

(measured)2

0.00718 atm-m3/mol

(measured)2

0.00275 atm-m3/mol

(measured)2

0.01992 atm-m3/mol

(measured)2

0.00044 atm-m3/mol

(measured)2

Water Solubility

642 mg/L at 25°C

(measured)2

39 mg/L at 25°C

(measured)2

1,800 mg/L at 25 °C

(measured)2

17.9 mg/L at 25°C (measured)2

9.5 mg/L at 25°C

(measured)2

42 mg/L at 25°C (measured)2

1,790 mg/L at 25°C

(measured)2

526 mg/L at 25°C

(measured)2

161 mg/L at 25°C

(measured)2

310 mg/L at 25°C

(measured)2

20 mg/L at 25°C (measured)4

31 mg/L at 25°C

(measured)2

Log Kow 2.42 (measured)2

3.39 (measured)2

2.25 (estimated)3

3.60 (measured)2 3.90 (measured)2

3.37 (measured)2 2.13 (measured)2

2.73 (measured)2

3.20 (measured)2

2.95 (measured)2

2.78 (measured)4 3.30 (measured)2

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Table 6. Physical-Chemical Properties of the High Benzene Naphthas Category1

SUPPORTING CHEMICALS Property

1,3-Butadiene, 2-methyl- (Isoprene)

n-Pentane 1,3-Cyclo-pentadiene

Pentane, 2-methyl-

(Isohexane)

n-Hexane Cyclopentane, methyl-

Benzene Benzene, methyl-

(Toluene)

Benzene, 1,3-dimethyl-

(m-Xylene)

Benzene, ethenyl- (Styrene)

4,7-Methano-1H-indene, 3a,4,7,7a-

tetrahydro- (Dicyclo-

pentadiene)

Naphthalene

1 American Chemistry Council (ACC) Olefins Panel HPV Work Group. 2004. Revised Robust Summary and Test Plan for High Benzene Naphthas Category. Available online at http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm as of September 28, 2010.

2 SRC. The Physical Properties Database (PHYSPROP). Syracuse, NY: Syracuse Research Corporation. Available online at http://www.syrres.com/esc/physprop.htm as of September 28, 2010.

3 U.S. EPA. 2010. Estimation Programs Interface Suite™ for Microsoft® Windows, v4.00. U.S. Environmental Protection Agency, Washington, DC, USA. Available online at http://www.epa.gov/opptintr/exposure/pubs/episuitedl.htm as of September 28, 2010.

4 OECD SIDS Initial Assessment Report for Dicyclopentadiene (77-73-6). Available online at http://www.chem.unep.ch/irptc/sids/OECDSIDS/77736.pdf as of September 28, 2010.  

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2. General Information on Exposure 2.1 Production Volume and Use Pattern The high benzene naphthas category consists of following eleven petroleum streams, only one with CASRN: Pyrolysis Gasoline, Pyrolysis C5-C6 Fraction, Pyrolysis C6 Fraction, Pyrolysis C6-C8 Fraction, Hydrotreated C6 Fraction, Hydrotreated C6-C7 Fraction, Hydrotreated C6-C8 Fraction, Aromatic Extract from Benzene Extraction, Quench Loop Pyrolysis oil and compressor oil and Recovered oil from wastewater treatment (CASRN 68956-70-7). For the nine streams with no CASRN, the following eighteen constituent chemicals were identified: CASRN 64741-99-7, 64742-49-0, 64742-73-0, 64742-83-2, 64742-91-2, 67891-79-6, 67891-80-9, 68410-97-9, 68475-70-7, 68476-45-9, 68526-77-2, 68606-10-0, 68606-28-0, 68921-67-5, 68955-29-3, 68956-52-5, 69013-21-4, and 8030-30-6. Following is the summary of IUR information for these nineteen chemicals. The nineteen chemicals in the high benzene naphthas category had an aggregated production and/or import volume in the United States greater than 13 billion 350 million pounds in calendar year 2005.

• CASRN 64741-99-7: 1 billion pounds and greater; • CASRN 64742-49-0: 1 billion pounds and greater; • CASRN 64742-73-0: 1 billion pounds and greater; • CASRN 64742-83-2: 1 billion pounds and greater; • CASRN 67891-79-6: 100 to < 500 million pounds; • CASRN 67891-80-9: 1 billion pounds and greater; • CASRN 68410-97-9: 1 billion pounds and greater; • CASRN 68475-70-7: 1 billion pounds and greater; • CASRN 68476-45-9: 50 to < 100 million pounds; • CASRN 68606-10-0: 1 billion pounds and greater; • CASRN 68606-28-0: 100 to < 500 million pounds; • CASRN 68921-67-5: 1 billion pounds and greater; • CASRN 68955-29-3: 100 to < 500 million pounds; • CASRN 68956-52-5: 1 billion pounds and greater; • CASRN 68956-70-7: 1 billion pounds and greater; • CASRN 69013-21-4: 1 billion pounds and greater; • CASRN 8030-30-6: 1 billion pounds and greater;

CASRN 64742-91-2 and 68526-77-2 were not reported in the 2006 IUR. CASRN 68606-10-0, 64742-83-2, 67891-79-6, 67891-80-9, 68476-45-9, 68606-28-0, 68956-52-5, 68956-70-7, 68410-97-9, 8030-30-6, 64742-73-0, 68475-70-7, 68921-67-5 and 64741-99-7: No industrial processing and uses, and commercial and consumer uses were reported for these chemicals.

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CASRN 64742-49-0: Non-confidential information in the IUR indicated that the industrial processing and uses of the chemical include petroleum refineries as fuels. Non-confidential commercial and consumer uses of this chemical include “other.” CASRN 68955-29-3: Non-confidential information in the IUR indicated that the industrial processing and uses of the chemical include petrochemical manufacturing, and resin and synthetic rubber manufacturing as “other.” Non-confidential commercial and consumer uses of this chemical include not otherwise obtainable (NRO). CASRN 69013-21-4: Industrial processing and uses, and commercial and consumer uses for the chemical were claimed confidential. 2.2 Environmental Exposure and Fate The environmental fate properties are for the sponsored streams and supporting chemicals are provided in Tables 7 and 8, respectively. The components of the high benzene naphthas category are expected to possess moderate mobility in soil. Benzene (CASRN 71-73-2) and n-pentane (CASRN 109-66-0) were readily biodegradable, achieving 63 and 87% biodegradation, respectively, within 28 days in manometric respirometry tests (OECD 301F). Styrene (CASRN 100-42-5) was readily biodegradable, achieving 68% of its theoretical biochemical oxygen demand over a 10-day incubation period also using the manometric respirometry test. Toluene (CASRN 108-88-3) was readily biodegradable, achieving 123% of its theoretical biochemical oxygen demand within 14 days in a MITI test (OECD 301C). m-Xylene (CASRN 108-38-3) and n-hexane (CASRN 110-54-3) were also readily biodegradable in MITI tests, with both achieving 100% biodegradation within 28 days. Naphthalene (CASRN 91-20-3) was only 0–2% biodegraded in 28 days in a MITI inherent test (OECD 302C), but in an aerobic test incorporating domestic wastewater as an inoculum, 100% degradation by DOC was seen over 7 days. Dicyclopentadiene (CASRN 77-73-6) was not readily biodegradable, achieving 0% of its theoretical biochemical oxygen demand over a 14-day incubation period using the modified MITI test. Isoprene (CASRN 78-79-5) was not readily biodegradable in a 28-day Closed Bottle test (OECD 301D), achieving only 2% of its theoretical biochemical oxygen demand, but had a biodegradation half-life of only 6 hours in temperate forest surface soil samples from Ithaca, NY at temperatures of 5–40°C. Although it did not biodegrade 60% within 10 days of exceeding the 10% biodegradation level, hydrogenated pyrolysis gasoline (CASRN 68410-97-9), which is associated with three of the streams in the high benzene naphthas category, achieved 68% biodegradation by theoretical oxygen demand within 28 days in a closed bottle test. Thus, hydrogenated pyrolysis gasoline was considered to be ultimately biodegradable, but not readily biodegradable. Volatilization is expected to be high for the members of the high benzene naphthas category based on their

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Henry’s Law constants. The rate of hydrolysis is expected to be negligible since the substances in this category do not possess functional groups that hydrolyze under environmental conditions. Most of the members of the high benzene naphthas category are expected to possess low persistence (P1). Pyrolysis gasoline, which contains 20% dicyclopentadiene, and quench loop pyrolysis oil and compressor oil, which contains 38.8–50% “C11+ compounds,” are expected to possess moderate persistence (P2). The members of the high benzene naphthas category are expected to possess low bioaccumulation potential (B1). Conclusion: The high benzene naphthas category is composed of 10 ethylene-manufacturing streams that share a common origin in the ethylene process and share similar compositions. The category consists of 19 CAS numbers, each of which represents at least one of the category production streams. (In some cases, a single CAS number is a component in more than one stream; see Table 1.) The sponsor has chosen 12 representative chemicals that are components of the sponsored petroleum streams to characterize their physicochemical and fate properties. The members of the high benzene naphthas category are liquids with moderate to high water solubility and high vapor pressure. The members of the high benzene naphthas category are expected to possess moderate mobility in soil. Volatilization is expected to be high based on the Henry’s Law constants of these substances. The rate of hydrolysis is expected to be negligible since the substances in this category do not possess functional groups that hydrolyze under environmental conditions. The rate of atmospheric photooxidation is considered slow to rapid. Most of the members of the high benzene naphthas category are expected to possess low persistence (P1). Pyrolysis gasoline, which contains 20% dicyclopentadiene, and quench loop pyrolysis oil and compressor oil, which contains 38.8–50% “C11+ compounds”, are expected to possess moderate persistence (P2). The members of the high benzene naphthas category are expected to possess low bioaccumulation potential (B1).

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Table 7. Environmental Fate Characteristics of the High Benzene Naphthas Category1

Property SPONSORED

CHEMICAL Pyrolysis Gasoline

(Dripolene)2,3

SPONSORED CHEMICALPyrolysis C5 – C6

Fraction3

SPONSORED CHEMICAL Pyrolysis

C6 Fraction3

SPONSORED CHEMICALPyrolysis C6 – C8

Fraction3

SPONSORED CHEMICAL Hydrotreated C6 Fraction3

SPONSORED CHEMICAL Hydrotreated

C6 – C7 Fraction3

SPONSORED CHEMICAL Hydrotreated

C6 – C8 Fraction6

SPONSORED CHEMICAL

Aromatic Extract from

Benzene Extraction3

SPONSORED CHEMICAL

Quench Loop Pyrolysis Oil

and Compressor

Oil7

SPONSORED CHEMICAL Recovered Oil

from Wastewater Treatment8

CASRN 68606-10-0; 68921-67-5; 64742-83-2; 64742-91-2; 67891-79-6; 67891-80-9; 68476-45-9; 68526-77-2; 68606-28-0; 68955-29-3

68955-29-3; 64742-83-2; 68956-52-5

68955-29-3; 64742-83-2; 68606-10-0

68475-70-7; 68955-29-3; 64742-83-2; 68476-45-9

68410-97-9; 8030-30-6

68410-97-9; 64742-49-0; 64742-73-0; 68955-29-3

68410-97-9 64741-99-7 69013-21-4 68956-70-7

Photodegradation Half-life

Photodegradation Half-life

0.84 hours to 5.1 days (estimated)4

1.8 hours to 5.1 days

(estimated)4

0.84 hours to 5.1 days (estimated)4

4.3 hours to 5.1 days

(estimated)4

1.7–5.1 days (estimated)7

8.9 hours to 5.1 days

(estimated)6

4.3 hours to 5.1 days

(estimated)6

2.1 hours to 5.1 days

(estimated)6

1.8 hours to 5.1 days (estimated)6

Hydrolysis Half-life Stable Biodegradation No Data No Data No Data No Data 68% in 28

days (10-day window not met, not readily biodegradable)5

68% in 28 days (10-day window not met, not readily biodegradable)7

68% in 28 days (10-day window not met, not readily biodegradable)7

No Data No Data No Data

Bioaccumulation Factor

BAF = 14.8–177

(estimated)4

BAF = 14.8–35.4

(estimated)4

BAF = 14.8–37.8

(estimated)4

BAF = 14.8–119

(estimated)4

BAF = 14.8–307

(estimated)4

BAF = 14.8–307

(estimated)6

BAF = 14.8–119

(estimated)6

BAF = 14.8–64.6

(estimated)6

BAF = 14.8–119

(estimated)6

BAF = 14.5–500

(estimated)6

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Table 7. Environmental Fate Characteristics of the High Benzene Naphthas Category1

Property SPONSORED

CHEMICAL Pyrolysis Gasoline

(Dripolene)2,3

SPONSORED CHEMICALPyrolysis C5 – C6

Fraction3

SPONSORED CHEMICAL Pyrolysis

C6 Fraction3

SPONSORED CHEMICALPyrolysis C6 – C8

Fraction3

SPONSORED CHEMICAL Hydrotreated C6 Fraction3

SPONSORED CHEMICAL Hydrotreated

C6 – C7 Fraction3

SPONSORED CHEMICAL Hydrotreated

C6 – C8 Fraction6

SPONSORED CHEMICAL

Aromatic Extract from

Benzene Extraction3

SPONSORED CHEMICAL

Quench Loop Pyrolysis Oil

and Compressor

Oil7

SPONSORED CHEMICAL Recovered Oil

from Wastewater Treatment8

Log Koc 1.75–2.96 (measured)6

1.75–2.14 (measured/)

4,6

1.75–2.24 (estimated)6

1.75–2.96 (measured)6

1.75–3.38 (measured/)4

,6

1.75–3.38 (measured/

estimated)6,8

1.75–2.25 (measured)8

1.75–2.96 (measured)8

1.75–3.36 (measured)8

1.75–3.36 (measured)8

Fugacity (Level III Model)4

Air (%) Water (%)

Soil (%) Sediment (%)

0.309–31.4 11.5–86.1 12.6–86.6

0.387–1.85

0.37–31.4 41.3–95.4 2.64–26.8

0.372–0.472

0.918–31.441.3–95.4 2.64–39.7

0.372–0.446

1.2–31.4 27.5–41.5 26.8–70.8

0.372–0.634

28.6–37.6 41.3–67.9

0.874–26.80.362–0.514

18.4–37.6 41.3–65.6

0.874–39.7 0.362–0.45

6.14–31.4 40.7–41.5 26.8–52.5

0.372–0.634

1.2–31.4 27.5–41.3 26.8–70.8

0.372–0.493

0.693–31.4 17.5–41.3 26.8–80.4

0.372–1.42

0.693–33.1 17.5–95.4

0.874–80.4 0.372–1.42

Persistence7 P2 (moderate) P1 (low) P1 (low) P1 (low) P1 (low) P1 (low) P1 (low) P1 (low) P2 (moderate)

P1 (low)

Bioaccumulation7 B1 (low) B1 (low) B1 (low) B1 (low) B1 (low) B1 (low) B1 (low) B1 (low) B1 (low) B1 (low)

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Table 7. Environmental Fate Characteristics of the High Benzene Naphthas Category1

Property SPONSORED

CHEMICAL Pyrolysis Gasoline

(Dripolene)2,3

SPONSORED CHEMICALPyrolysis C5 – C6

Fraction3

SPONSORED CHEMICAL Pyrolysis

C6 Fraction3

SPONSORED CHEMICALPyrolysis C6 – C8

Fraction3

SPONSORED CHEMICAL Hydrotreated C6 Fraction3

SPONSORED CHEMICAL Hydrotreated

C6 – C7 Fraction3

SPONSORED CHEMICAL Hydrotreated

C6 – C8 Fraction6

SPONSORED CHEMICAL

Aromatic Extract from

Benzene Extraction3

SPONSORED CHEMICAL

Quench Loop Pyrolysis Oil

and Compressor

Oil7

SPONSORED CHEMICAL Recovered Oil

from Wastewater Treatment8

1 American Chemistry Council (ACC) Olefins Panel HPV Work Group. 2004. Revised Robust Summary and Test Plan for High Benzene Naphthas Category. Available online at http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm as of September 28, 2010.

2 According to the sponsor, Dripolene and pyrolysis gasoline are synonymous. 3 Data range is based upon the compositional data provided by the sponsor in the test plan from which representative structures were derived; see the Appendix for

detailed information on structures and composition. 4 U.S. EPA. 2010. Estimation Programs Interface Suite™ for Microsoft® Windows, v4.00. U.S. Environmental Protection Agency, Washington, DC, USA. Available

online at http://www.epa.gov/opptintr/exposure/pubs/episuitedl.htm as of September 28, 2010. 5 American Chemistry Council (ACC) Olefins Panel HPV Work Group. 2002. OECD 301D for Hydrogenated Pyrolysis Gasoline (CASRN 68410-97-9). Original

Robust Summary for High Benzene Naphthas Category. Available online at http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436rs.pdf as of September 28, 2010.

6 SRC. The Physical Properties Database (PHYSPROP). Syracuse, NY: Syracuse Research Corporation. Available online at http://www.syrres.com/esc/physprop.htm as of September 28, 2010.

7 Federal Register. 1999. Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances. Federal Register 64, Number 213 (November 4, 1999) pp. 60194–6020. 1 American Chemistry Council (ACC) Olefins Panel HPV Work Group. 2004. Revised Robust Summary and Test Plan for High Benzene Naphthas Category. Available online at http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm as of September 28, 2010. 2 Data range is based upon the compositional data provided by the sponsor in the test plan from which representative structures were derived; see the Appendix for detailed information on structures and composition. 3 The sponsored substance “Hydrotreated C6 – C8 fraction” is tentatively considered acceptable as a High Benzene Naphtha member, although the sponsor did not fully characterize the composition of the 20–26% “non-aromatic hydrocarbons” portion of this stream. The data range for this stream is based only on those components for which representative structures could be derived from the compositional data provided by the sponsor in the revised test plan; see the Appendix for detailed information on structures and composition. 4 The sponsor did not fully categorize the composition of the “C11+ compounds” portion of Quench Loop Pyrolysis Oil and Compressor Oil stream. The lack of characterization of this component raises the potential for polyaromatic hydrocarbons in this stream. The data range for this stream is based upon components for which representative structures could be derived from the compositional data provided by the sponsor in the revised test plan with 1-methylnaphthalene as a representative compound for the “C11+ compounds” portion of this stream; see the Appendix for detailed information on structures and composition. 5 No compositional data were provided for this stream. Data range and representative structures are based upon the CAS definition for the CAS number provided for this stream. 6 U.S. EPA. 2010. Estimation Programs Interface Suite™ for Microsoft® Windows, v4.00. U.S. Environmental Protection Agency, Washington, DC, USA. Available online at http://www.epa.gov/opptintr/exposure/pubs/episuitedl.htm as of September 28, 2010. 7 American Chemistry Council (ACC) Olefins Panel HPV Work Group. 2002. OECD 301D for Hydrogenated Pyrolysis Gasoline (CASRN 68410-97-9). Original Robust Summary for High Benzene Naphthas Category. Available online at http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436rs.pdf as of September 28, 2010. 8 SRC. The Physical Properties Database (PHYSPROP). Syracuse, NY: Syracuse Research Corporation. Available online at http://www.syrres.com/esc/physprop.htm as of September 28, 2010. 9 Federal Register. 1999. Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances. Federal Register 64, Number 213 (November 4, 1999) pp. 60194–6020. 

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Table 8. Environmental Fate Characteristics of the High Benzene Naphthas Category1

SUPPORTING CHEMICALS Property

1,3-Butadiene, 2-methyl- (Isoprene)

n-Pentane 1,3-Cyclo-pentadiene

Pentane, 2-methyl-

(Isohexane)

n-Hexane Cyclopentane, methyl-

Benzene Benzene, methyl-

(Toluene)

Benzene, 1,3-dimethyl-

(m-Xylene)

Benzene, ethenyl- (Styrene)

4,7-Methano-1H-indene, 3a,4,7,7a-

tetrahydro- (Dicyclo-

pentadiene)

Naphthalene

CASRN 78-79-5 109-66-0 542-92-7 107-83-5 110-54-3 96-37-7 71-43-2 108-88-3 108-38-3 100-42-5 77-73-6 91-20-3 Photodegradation Half-life

1.2 hours (estimated)2

32 hours (estimated)2

0.84 hours (estimated)2

1.7 days (estimated)2

1.8 days (estimated)2

1.8 days (estimated)2

5.1 days (estimated)2

1.9 days (estimated)2

8.9 hours (estimated)2

4.3 hours (estimated)2

1.1 hours (estimated)2

5.6 hours (estimated)2

Hydrolysis Half-life

Stable

Biodegradation 2% in 28 days (not readily biodegradable)3

; half-life in surface soil = 6 hours at 5–40°C4

87% in 28 days (readily biodegradable); 96% in 28 days (readily biodegradable)3

No Data No Data 100% in 28 days (readily biodegradable)3

No Data 63% in 28 days (readily bio-degradable)

100–123% in 14 days (readily bio-degradable)3

100% in 28 days (readily bio-degradable)3

100% in 14 days (inherently bio-degradable)3; 68% in 10 days (readily bio-degradable)6

0% in 14 days (not readily bio-degradable)3

0–2% in 28 days (not inherently bio-degradable)3; 100% in 7 days (inherently bio-degradable)9

Bioaccumulation Factor

BCF = 5.0–14 (measured in carp at 50 ppb)3; BCF = <5.6–20 (measured in carp at 5 ppb)3;

BAF = 21.4 (estimated)2

BAF = 150 (estimated)2

BAF = 16.5 (estimated)2

BAF = 196 (estimated)2

BAF = 307 (estimated)2

BAF = 146 (estimated)2

BAF = 14.8 (estimated)2

BAF = 37.8 (estimated)2

BAF = 119 (estimated)2

BAF = 64.6 (estimated)2

BCF = 112–330 (measured in carp at 0.3 ppm)3; BCF = 58.9–384 (measured in carp at 0.03 ppm)3; BAF = 59.6 (estimated)2

BCF = 36–168 (measured in carp at 0.15 ppm)3; BCF = 23–146 (measured in carp at 0.015 ppm)3; BAF = 177 (estimated)2

Log Koc 2.10 (estimated)2

1.86 (estimated)2

1.95 (estimated)2

3.12 (estimated)2

3.38 (estimated)2

2.92 (estimated)2

1.75 (measured)8

2.07 (measured)8

2.25 (measured)8

2.96 (measured)8

2.41 (estimated)2

2.96 (measured)8

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Table 8. Environmental Fate Characteristics of the High Benzene Naphthas Category1

SUPPORTING CHEMICALS Property

1,3-Butadiene, 2-methyl- (Isoprene)

n-Pentane 1,3-Cyclo-pentadiene

Pentane, 2-methyl-

(Isohexane)

n-Hexane Cyclopentane, methyl-

Benzene Benzene, methyl-

(Toluene)

Benzene, 1,3-dimethyl-

(m-Xylene)

Benzene, ethenyl- (Styrene)

4,7-Methano-1H-indene, 3a,4,7,7a-

tetrahydro- (Dicyclo-

pentadiene)

Naphthalene

Fugacity (Level III Model)2

Air (%) Water (%)

Soil (%) Sediment (%)

3.63 92.2 3.78 0.398

43 56

0.91 0.23

0.918 86.1 12.6 0.437

33.1 65.6 0.874 0.423

37.6 61

1.03 0.362

33 65.1 1.51 0.45

31.4 41.3 26.8 0.372

18.4 41.5 39.7 0.446

6.14 40.7 52.5 0.634

1.2 27.5 70.8 0.493

0.309 36.3 61.5 1.85

0.842 11.5 86.6 0.998

Persistence5 P1 (low) P1 (low) P1 (low) P1 (low) P1 (low) P1 (low) P1 (low) P1 (low) P1 (low) P1 (low) P2 (moderate) P1 (low) Bioaccumulation5 B1 (low) B1 (low) B1 (low) B1 (low) B1 (low) B1 (low) B1 (low) B1 (low) B1 (low) B1 (low) B1 (low) B1 (low) 1 American Chemistry Council (ACC) Olefins Panel HPV Work Group. 2004. Revised Robust Summary and Test Plan for High Benzene Naphthas Category. Available online at

http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm as of September 28, 2010. 2 U.S. EPA. 2010. Estimation Programs Interface Suite™ for Microsoft® Windows, v4.00. U.S. Environmental Protection Agency, Washington, DC, USA. Available online at

http://www.epa.gov/opptintr/exposure/pubs/episuitedl.htm as of September 28, 2010. 3 National Institute of Technology and Evaluation. 2002. Biodegradation and Bioaccumulation of the Existing Chemical Substances under the Chemical Substances Control Law. Available

online at http://www.safe.nite.go.jp/english/kizon/KIZON_start_hazkizon.html as of October 12, 2010. 4Cleveland, CC; Yavitt, JB. 1998. Microbial consumption of atmospheric isoprene in a temperate forest soil. Appl Environ Microbiol 64(1):172–177. 5 Federal Register. 1999. Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances. Federal Register 64, Number 213 (November 4, 1999) pp. 60194–6020. 6 E.U. European Chemicals Bureau. 2002. European Union Risk Assessment Report on Styrene. Available online at http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/styrenereport034.pdf as of September 28, 2010.

7 Tabak, HH; Quave, SA; Mashni, CI; et al. 1981. Biodegradability studies with organic priority pollutant compounds. J Water Pollut Control Fed 53:1503–1518. 8 SRC. The Physical Properties Database (PHYSPROP). Syracuse, NY: Syracuse Research Corporation. Available from http://www.syrres.com/esc/physprop.htm as of September 28, 2010. 9 Federal Register.  1999.  Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances.  Federal Register 64, Number 213 (November 4, 1999) pp. 60194–6020. 

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3. Human Health Hazard A summary of health effects data submitted for SIDS endpoints is provided in Tables 9 and 10. The table also indicates where data for tested category members are read-across (RA) to untested members of the category. Acute Oral Toxicity Subcategory I: Pygas Pyrolysis gasoline (Dripolene) (No CASRN) Sprague-Dawley rats (5 sex/dose) were administered neat Dripolene via gavage at a single dose of 2000 mg/kg and observed for 14 days following dosing. No mortalities occurred. LD50 > 2000 mg/kg Rerun Tower Overheads (CASRN 64741-74-8, supporting chemical) Sprague-Dawley rats (5 sex/dose) were administered the rerun tower overhead mixture via gavage at a single dose of 2000 mg/kg and observed for 14 days following dosing. No mortalities occurred. LD50 > 2000 mg/kg 1,3-Cyclopentadiene (CASRN 542-92-7, supporting chemical) Rat LD50 < 1000 mg/kg Hexane (CASRN 110-54-3, supporting chemical) Rat LD50 = 28,700 mg/kg Subcategory II: High Benzene Naphthas Hydrogenated pyrolysis gasoline (CASRN 68410-97-9, Hydrotreated C6 – C8 Fraction) Fischer 344 rats (5sex/dose) were administered hydrogenated pyrolysis gasoline via unspecified oral route at doses of 4200, 4600, 5000 or 5400 mg/kg and observed for 14 days following dosing. Mortalities occurred only at the highest two dose levels (7/20 and 7/10 rats at doses of 5000 and 5400 mg/kg, respectively). At the 5000 mg/kg dose level, results from a previous acute toxicity test were combined with the results for this one (resulting in 20 animals in that dose group). LD50 = 5170 mg/kg Subcategory III: Quench/Compressor Oil Benzene (CASRN 71-43-2, supporting chemical) See human health data at: http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/benzenereport063.pdf) Rat LD50 > 810-10,000 mg/kg Toluene (CASRN 108-88-3, supporting chemical) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://ecb.jrc.ec.europa.eu/esis/ Rat LD50 = 5500 – 7500 mg/kg

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Xylenes, mixed (CASRN 1330-20-7, supporting chemical) See human health data at: http://ecb.jrc.ec.europa.eu/esis/ Rat LD50 = 3523 – 11,000 mg/kg Styrene (CASRN 100-42-5, supporting chemical) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://cerhr.niehs.nih.gov/evals/styrene/Styrene_final.pdf Rat LD50 = 2650 mg/kg Mouse LD50 = 316 mg/kg Naphthalene (CASRN 91-20-3, supporting chemical) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://ecb.jrc.ec.europa.eu/esis/ Rat LD50 (rat) > 2000 mg/kg Mouse LD50 = 533 mg/kg (male) – 710 mg/kg (female) Note: Rodents are not suitable animal models for the acutely toxic human health effects of naphthalene in relation to haemolytic anaemia. The LD50 results from the rat suggest relatively low acute toxicity in this species, but the available information in humans indicates significant toxicity. Dicyclopentadiene (CASRN 77-73-6, supporting chemical) See human health data at: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=c1669b2f-fe19-4ff0-8761-4d0e436e73e2&idx=0. Rat LD50 = 590 mg/kg Acute Inhalation Toxicity Subcategory I: Pygas Isoprene (CASRN 78-79-5, supporting chemical) See human health data at: http://www.chem.unep.ch/irptc/sids/OECDSIDS/78795.pdf Rat LC50 = 64,500 ppm (2-h; ~ 180 mg/L) Mouse LC50 = 56,363 ppm (2-h; ~157 mg/L) Pentane (CASRN 109-66-0, supporting chemical) See human health data for CASRN 109-66-0: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=0af02fa3-f3ef-4df9-b050-43116efd8ef1&idx=0 and C5 aliphatic hydrocarbon solvents category - http://webnet.oecd.org/hpv/ui/Search.aspx. Rat LC50 > 18.0 mg/L 1,3-Cyclopentadiene (CASRN 542-92-7, supporting chemical) Rat LC50 = 14,426 ppm (~ 39 mg/L) Hexane (CASRN 110-54-3, supporting chemical) Rat LC50 = 48,000 ppm

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Benzene (CASRN 71-43-2, supporting chemical) (1) Sprague-Dawley rats (10 females/test concentration) were exposed to benzene via inhalation at unspecified concentrations for 4 hours and observed for 14 days following dosing. Mortality was not specified. LC50 = 43.7 mg/L (2) See human health data at http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/benzenereport063.pdf Toluene (CASRN 108-88-3, supporting chemical) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/toluenereport032.pdf. Rat LC50 = 22.0 – 45.8 mg/L Mouse LC50 = 19.9 – 27.9 mg/L Xylenes, mixed (CASRN 1330-20-7, supporting chemical) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=296&tid=53. Rat LC50 = 18.8 mg/L Mouse LC50 = 16.9 mg/L Styrene (CASRN 100-42-5, supporting chemical) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://cerhr.niehs.nih.gov/evals/styrene/Styrene_final.pdf Rat LC50 = 11.8 mg/L (2710 ppm) Rat LC50 = 9.5 mg/L (2185 ppm) Naphthalene (91-20-3, supporting chemical) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://ecb.jrc.ec.europa.eu/esis/ Rat LC50 > 78 ppm Dicyclopentadiene (CASRN 77-73-6, supporting chemical) See human health data at: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=c1669b2f-fe19-4ff0-8761-4d0e436e73e2&idx=0. Rat LC50 = 1000 ppm/4-h Subcategory II: High Benzene Naphthas Hydrogenated pyrolysis gasoline (CASRN 68410-97-9, Hydrotreated C6 – C8 Fraction) Fischer 344 rats (5/sex/dose) were exposed whole-body to hydrogenated pyrolysis gasoline as an aerosol at measured concentrations ranging from 8642 to 17,371 ppm (average 12,408 ppm) for 4 hours and observed for 14 days following dosing. No mortalities occurred. NOTE: Because the test substance is a complex mixture for which exact component identify and concentration is not known, conversion from ppm to mg/L in air is not possible. LC50 > 12,408 ppm

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Subcategory III: Quench/Compressor Oil See data for CASRNs 71-43-2, 108-88-3, 1330-20-7, 100-42-5, 91-20-3 and 77-73-6 in subcategory I above. Acute Dermal Toxicity Subcategory I: Pygas Pyrolysis Gasoline (Dripolene) (No CASRN) New Zealand White rabbits (3 sex/dose) were administered Dripolene via the dermal route at 2000 mg/kg under occluded conditions for 24 hours and observed for 14 days following dosing. No mortalities occurred. LD50 > 2000 mg/kg Rerun Tower Overheads (CASRN 64741-74-8, supporting chemical) New Zealand white rabbits (3 sex/dose) were administered the rerun tower overhead mixture via the dermal route at 2000 mg/kg under occluded conditions for 24 hours and observed for 14 days following dosing. No mortalities occurred. LD50 > 2000 mg/kg Subcategory III: Quench/Compressor Oil Toluene (CASRN 108-88-3, supporting chemical) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://ecb.jrc.ec.europa.eu/esis/ Rabbit LD50 = 12,400 mg/kg Naphthalene (91-20-3, supporting chemical) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://ecb.jrc.ec.europa.eu/esis/ Rat LD50 > 2500 mg/kg Rabbit LD50 > 2000 mg/kg Repeated-Dose Toxicity Subcategory I: Pygas Rerun Tower Overheads (CASRN 64741-74-8, supporting chemical) New Zealand white rabbits (4/sex/dose) were administered the rerun tower overhead mixture via the dermal route at doses of 0, 0.1, 0.5 and 1 mL/kg/day (assuming a density of 1 g/mL; this is equivalent to 100, 500 and 1000 mg/kg/d) daily for 21 days. The dorsal area of the animals was clipped of hair and the skin was abraded. Daily application of the test material was done without wiping off and the animals wore a collar to prevent ingestion of the test article. No treatment-related mortalities occurred. The following local effects were observed in a dose-related manner (in terms of both incidence and severity): erythema, skin thickening, fissuring and necrosis. There were no significant systemic effects noted (parameters evaluated included body weight, food consumption, organ weight or histopathology, urinalysis or hematology [with the exception of elevated basophils in all treated males]. LOAEL (local) = 100 mg/kg/day (irritation, lowest dose tested) NOAEL (systemic) > 1000 mg/kg/day (highest dose tested)

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Isoprene (CASRN 78-79-5, supporting chemical) Repeated dose studies demonstrate clear species differences between rats and mice in susceptibility to isoprene. See human health data at: http://www.chem.unep.ch/irptc/sids/OECDSIDS/78795.pdf Mouse LOAEC = 700 ppm/day ( ~ 1.95 mg/L/day; based on hematological effects and histopathological changes in forestomach, olfactory epithelium and liver) Mouse NOAEC = 200 ppm/day (~ 0.61 mg/L/day) Rat NOAEC = 7000 ppm/day (~19.5 mg/L/day; highest concentration tested) Pentane (CASRN 109-66-0) (1) In a 90-day study, rats were exposed to pentane via inhalation at concentrations ranging from 5 to 20 mg/L. No adverse effects were observed (C5 aliphatic hydrocarbon solvents category - http://webnet.oecd.org/hpv/ui/Search.aspx). NOAEC = 20 mg/L/day (highest concentration tested) (2) See human health data for CASRN 109-66-0: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=0af02fa3-f3ef-4df9-b050-43116efd8ef1&idx=0 and C5 aliphatic hydrocarbon solvents category - http://webnet.oecd.org/hpv/ui/Search.aspx. 1,3-Cyclopentadiene (CASRN 542-92-7, supporting chemical) See data in Table 10 extracted from Appendix in Category Summary of HPV Challenge submission for high benzene naphthas category: http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436rt2.pdf Hexane (CASRN 110-54-3, supporting chemical) See human health data summarized in EPA IRIS assessment: http://www.epa.gov/iris/toxreviews/0486tr.pdf Methylcyclopentane (CASRN 96-37-7, supporting chemical) See data in Table 10 extracted from Appendix in Category Summary of HPV Challenge submission for high benzene naphthas category: http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436rt2.pdf Benzene (CASRN 71-43-2, supporting chemical) (1) In a 10-week study, CD-1 mice (11 – 12 males/test concentration) were exposed to benzene via inhalation at 0 or 9.6 ppm (0 or 0.03 mg/L), 6 hours/day, 5 days/week. Hematological parameters were evaluated at the end of exposure. No mortality was observed. Increases were observed in spleen weight, total nucleated cells per spleen and nucleated red blood cells (RBCs) at 0.03 mg/L. LOAEC ~ 0.03 mg/L/day (based on increases in spleen weight, total nucleated cells per spleen and nucleated RBCs) NOAEC = Not established (2) In a 13-week study, CD-1 mice (40/sex/test concentration) were exposed whole-body to benzene as a vapor at 0, 1, 10, 30 or 300 ppm (approximately 0, 0.003, 0.03, 0.10 or 0.96 mg/L),

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6 hours/day, 5 days/week. Endpoints included behavior, body weights, organ weights, clinical pathology, gross pathology, histopathology, hematology and clinical chemistry. At ~0.96 mg/L, hematological effects included decreases in RBC counts, WBC counts, platelets, hemoglobin, myeloid/erythroid ratios and hematocrit. Other effects at ~0.96 mg/L included femoral myeloid hypoplasia, extramedullary hemotopoiesis in the spleen, thymic atrophy, decreases in absolute and relative testis weights, minimal to moderately severe bilateral atrophy/degeneration of testes, moderate to moderately severe decreases in spermatozoa and a minimal to moderate increase in abnormal sperm morphology. Bilateral ovarian cysts were observed in four females at 0.96 mg/L. Histopathological changes were also observed in mesenteric and mandibular lymph nodes, as well as in the liver at ~0.96 mg/L. LOAEC ~ 0.96 mg/L/day (based on decreases in RBC counts, WBC counts, platelets, hemoglobin, myeloid/erythroid ratios and hematocrit, femoral myeloid hypoplasia, extramedullary hemotopoiesis in the spleen, thymic atrophy, decreases in absolute and relative testis weights, minimal to moderately severe bilateral atrophy/degeneration of testes, moderate to moderately severe decreases in spermatozoa, a minimal to moderate increase in abnormal sperm morphology, bilateral ovarian cysts and unspecified histopathological changes in the liver and mesenteric and mandibular lymph nodes) NOAEC ~ 0.10 mg/L/day (3) Several studies are described in the OECD SIDS documents at: http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/benzenereport063.pdf. Toluene (CASRN 108-88-3, supporting chemical) Several studies are available for repeated exposures of toluene to animals (see references below). (1) Subchronic 13- week oral rat study: LOAEL = 446 mg/kg-day (increased relative and absolute liver and kidney weights of male rats) NOAEL = 223 mg/kg-day (2) Subchronic 13-week oral mouse study: LOAEL = 312 mg/kg-day (based on increased absolute and relative liver weights in female mice) NOAEL = Not established (3) 14-week inhalation rat study: LOAEC = 1250 ppm/day (~ 4.7 mg/L/day) (based on changes in relative liver weight in males) NOAEC = 625 ppm/day (~ 2.4 mg/L/day) (4) 14-week inhalation mouse study:LOAEC = 625 ppm/day (~ 2.4 mg/L/day) (based on mortality and relative liver weight in both sexes) NOAEC = 100 ppm/day (~ 0.38 mg/L/day) (5) Lifetime inhalation exposure of rats caused degeneration of nasal epithelium and increased incidence of stomach ulcers.

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LOAEC = 600 ppm/day (~ 2.4 mg/L/day) (based on increased incidence of stomach ulcers; the LOAEC for hearing loss is 700 ppm/day) NOAEC = 300 ppm/day (~ 1.1 mg/L/day) (6) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx, http://www.epa.gov/iris/subst/0118.htm and http://www.epa.gov/oppt/vccep/pubs/chem13a.html Xylenes, mixed (CASRN 1330-20-7, supporting chemical) Repeated-dose studies in several species are available. See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=296&tid=53. (1) Rats exposed to mixed xylenes by inhalation daily for up to six months showed liver effects at 923 ppm/day (approximately 4.0 mg/L/day). http://webnet.oecd.org/hpv/UI/Search.aspx LOAEC = 923 ppm/day (~ 4.0 mg/L/day) (based on increased relative liver weight, histopatholgy, and enzyme activity) NOAEC = 346 ppm/day (~ 1.5 mg/L/day) (2) In 13-week repeated-dose studies, rats treated with mixed xylenes by the oral route showed decreased body weight gain but no overt signs of toxicity at 2000 mg/kg/day. http://webnet.oecd.org/hpv/UI/Search.aspx LOAEL = 2000 mg/kg/day (based on decreased body weight gain) NOAEL = 1000 mg/kg/day (3) In 13-week repeated-dose studies, mice treated with mixed xylenes by the oral route showed mortality at 2000 mg/kg/day. http://webnet.oecd.org/hpv/UI/Search.aspx LOAEL = 2000 mg/kg/day (based on mortality) NOAEL = 1000 mg/kg/day Styrene (CASRN 100-42-5, supporting chemical) Several repeated-dose studies in rats and mice are available. Mice appear to be more sensitive to inhalation toxicity than rats. Generally, inhalation exposures show histopathological changes in the olfactory epithelium whereas effects on the auditory system are observed at higher concentrations. (1) Four-week inhalation toxicity study in rats showed ototoxicity at concentrations > 300 ppm. Additional information not provided: http://ec.europa.eu/health/ph_risk/committees/04_scher/docs/scher_o_095.pdf LOAEC > 300 ppm (~1.28 mg/L/day) NOAEC = 300 ppm (~1.28 mg/L/day) (2) Two-year oral toxicity study in mice showed effects on nose, liver and lung. Additional information not provided. http://ec.europa.eu/health/ph_risk/committees/04_scher/docs/scher_o_095.pdf LOAEL > 150 mg/kg/day NOAEL = 150 mg/kg/day

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(3) In repeated inhalation exposures with rats, the NOAEC is 200 ppm (approximately 0.85 mg/L/day) based on the observance on neurotoxicity at higher concentrations. Histopathological changes in the olfactory epithelium indicating respiratory tract irritation was observed at 500 ppm (approximately 2.13 mg/L/day) and above and damage to the auditory system (hair cell loss) with associated functional impairment was observed at 800 ppm (approximately 3.41 mg/L/day). Additional information not provided. http://webnet.oecd.org/hpv/UI/Search.aspx (4) Long-term studies (120 weeks) in rats and mice showed liver, kidney and stomach lesions in rats (weekly at 500 mg/kg) and no significant effects in mice (weekly with 300 mg/kg). Other subchronic rat feeding studies showed LOAELs in the 350-500 mg/kg-day range and NOAELs in the 100-400 mg/kg-day range. http://cfpub.epa.gov/ncea/iris/index.cfm?fuseaction=iris.showKeywordResults&maxrows=15&startrow=1&textfield=100-42-5&searchtype=irisdata LOAEL = 350-500 mg/kg-day (based on systemic effects in rats) NOAEL = 100-400 mg/kg-day (5) In a two-year drinking water study, no adverse effects were observed in rats exposed to styrene at 35 mg/kg/day. http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=421&tid=74 NOAEL = 35 mg/kg/day (highest dose tested) (6) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx, http://ec.europa.eu/health/ph_risk/committees/04_scher/docs/scher_o_095.pdf and http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=421&tid=74 Naphthalene (CASRN 91-20-3, supporting chemical) (1) In a 13-week study, F344 rats treated with naphthalene in corn oil by gavage. Mortality in males at the high dose and clinical effects were observed; however, decreased body weight was the most sensitive effect noted6. LOAEL = 200 mg/kg/day (based on decreased body weight) NOAEL = 100 mg/kg/day (2) Albino CD-mice were administered naphthalene in corn oil by gavage. Effects were observed on the organ weights at 133 mg/kg-day. LOAEL = 133 mg/kg-day (based on decreased relative spleen weight, clinical chemistry) NOAEL = 53 mg/kg-day (3) In a 105-week study, F344 rats were exposed to naphthalene vapor via inhalation up to 60 ppm/day (approximately 0.3 mg/L/day). Neuroblastoma of the nasal olfactory epithelium was observed in both sexes. No lung tumors were observed. The incidences of a variety of non-neoplastic lesions of the nasal tract in both sexes were statistically significantly greater in treated animals when compared to controls. LOAEC (male) = 10 ppm/day (~ 0.05 mg/L/day; based on increased incidence of respiratory epithelial adenomas) NOAEC (male) = Not established 6 ATSDR and EPA IRIS: Decreased body weights in rats exposed by gavage to naphthalene 5 days/week for 13 weeks (NTP 1980) are used as a basis for derivation of the MRL and RfD, respectively.

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LOAEC (female) = 30 ppm/day (~0.15 mg/L/day; based on increased incidence of respiratory epithelial adenomas) NOAEC (female) = 10 ppm/day (~ 0.05 mg/L/day) (4) In a 104-week study, B6C3F1 mice were exposed to naphthalene vapor via inhalation up to 30 ppm/day (approximately 0.15 mg/L/day). A statistically significant increase in the incidence of alveolar/bronchiolar adenomas in high-exposure females was seen. Non-neoplastic changes were only seen in the lungs and nose where a dose-related increase in alveolar and bronchial inflammation was noted in all groups. LOAEC = 10 ppm (~ 0.05 mg/L/day; based on nasal and lung lesions) NOAEC = Not established (5) Rats treated with up to 1000 mg/kg/day naphthalene via the dermal route showed no adverse effects. NOAEL = 1000 mg/kg/day (highest dose tested) (6) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx, http://www.epa.gov/iris/subst/0436.htm, http://ecb.jrc.ec.europa.eu/esis/ and http://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=240&tid=43. Dicyclopentadiene (CASRN 77-73-6, supporting chemical) In a combined oral repeated-dose/reproductive/developmental toxicity screening test in rats, decreased body weights were seen in both sexes at 100 mg/kg-day and histopathological changes in the liver and kidney were observed in males at 20 mg/kg/day. See human health data at: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=c1669b2f-fe19-4ff0-8761-4d0e436e73e2&idx=0. LOAEL = 20 mg/kg-day (based on single cell necrosis in the liver, hyaline droplets and tubular changes in the kidneys in males) NOAEL = 4 mg/kg-day Subcategory II: High Benzene Naphthas See data for CASRNs 78-79-5, 109-66-0, 542-92-7, 110-54-3, 96-37-7, 71-43-2, 108-88-3, 1330-20-7, 100-42-5 and 77-73-6 above. Hydrogenated pyrolysis gasoline (CASRN 68410-97-9, Hydrotreated C6 – C8 Fraction) Fischer 344 rats (5/sex/dose) were exposed whole-body to hydrogenated pyrolysis gasoline as an aerosol at measured concentrations of 0, 4869 or 9137 ppm for 6 hours/day for five days and observed for two days post-exposure. Three animals (one male and two females) died in the high concentration group. All treated animals showed clinical signs (ocular discharge, increased respiratory rates, lethargy) and animals in the high concentration group also showed twitching and harsh respiratory sounds during exposures. Body weight was decreased in both treatment groups. NOTE: Because the test substance is a complex mixture for which exact component identify and concentration is not known, conversion from ppm to mg/L in air is not possible. The lowest concentration (4869 ppm) did cause some effects, so there is no NOAEC. Note: this study is not considered acceptable for the repeated-dose endpoint, but is provided for informational purposes only.

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Subcategory III: Quench/Compressor Oil See data for CASRNs 71-43-2, 108-88-3, 1330-20-7, 100-42-5, 91-20-3 and 77-73-6 above. Reproductive Toxicity Subcategory I: Pygas Isoprene (CASRN 78-79-5, supporting chemical) No guideline reproductive toxicity studies are available. However, significant effects on reproductive endpoints were observed in 13-week inhalation repeated dose studies with male mice exposed to isoprene at concentrations of 700 ppm/day (~ 1.95 mg/L/day) and above. These effects included testicular atrophy and decreases in epididymal weight, sperm head count, sperm concentration and sperm motility. See human health data at: http://www.chem.unep.ch/irptc/sids/OECDSIDS/78795.pdf Pentane (CASRN 109-66-0, supporting chemical) No specific reproductive toxicity study is available. However, in the 90-day inhalation repeated-dose inhalation study with rats described previously, no effects on the reproductive organs were observed (CASRN 109-66-0: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=0af02fa3-f3ef-4df9-b050-43116efd8ef1&idx=0 and C5 aliphatic hydrocarbon solvents category - http://webnet.oecd.org/hpv/ui/Search.aspx). Hexane (CASRN 110-54-3, supporting chemical) See human health data summarized in EPA IRIS assessment: http://www.epa.gov/iris/toxreviews/0486tr.pdf Benzene (CASRN 71-43-2, supporting chemical) (1) In the 13-week inhalation study in CD-1 mice described previously, effects on male reproductive organs at 0.96 mg/L included decreases in absolute and relative testes weights, minimal to moderately severe bilateral atrophy/degeneration of testes, moderate to moderately severe decreases in spermatozoa and a minimal to moderate increase in abnormal sperm morphology. In addition, bilateral ovarian cysts were observed in four females at 0.96 mg/L. (2) See human health data at: http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/benzenereport063.pdf. Toluene (CASRN 108-88-3, supporting chemical) (1) In a study designed to examine the effects of toluene on fertility, Sprague-Dawley rats were exposed to toluene up to 2000 ppm/day (approximately 7.5 mg/L/day) via inhalation. Toluene significantly decreased sperm count and epididymal weight at the high dose. http://www.epa.gov/iris/toxreviews/0118tr.pdf LOAEC (reproductive toxicity, female) = 2000 ppm/day (~ 7.5 mg/L/day) (highest concentration tested) LOAEC (reproductive toxicity, male) = 2000 ppm/day (~ 7.5 mg/L/day) (based on decreased sperm count) NOAEC (reproductive toxicity, male) = 600 ppm/day (~ 2.3 mg/L/day)

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(2) In a two-generation inhalation reproductive toxicity study, CD-1 rats were exposed by whole-body inhalation to toluene up to 2000 ppm/day (approximately 7.54 mg/L/day). No differences were observed in male or female fertility indices, length of gestation, mean numbers of viable and nonviable pups at birth, or pup survival indices during lactation in either the F0 or F1 generation. A statistically significant (p<0.05) decrease in pup weights relative to controls was observed in the first generation offspring (weeks 19-36) and maintained throughout lactation period in the F1 pups from F0 dams exposed to 2000 ppm. LOAEC (reproductive toxicity) = 2000 ppm/day (~ 7.5 mg/L/day) (based on decreased pup weights) NOAEC (reproductive toxicity) = 600 ppm/day (~ 2.3 mg/L/day) (3) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx, http://www.epa.gov/iris/toxreviews/0118tr.pdf and http://www.epa.gov/oppt/vccep/pubs/chem13a.html Xylenes, mixed (CASRN 1330-20-7, supporting chemical) (1) In a one-generation reproductive toxicity study, rats exposed via inhalation to mixed xylenes showed no dose-related effects on mating indices, mean duration of gestation, mean litter size, or pup survival. NOAEC (reproductive toxicity) = 500 ppm (~ 2.2 mg/L; highest concentration tested) (2) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=296&tid=53. Styrene (CASRN 100-42-5, supporting chemical) (1) In a 90-day inhalation toxicity study in rats, no evidence of testicular effects were observed up to 1500 ppm (approximately 6.39 mg/L/day). (2) In a two-generation inhalation reproductive toxicity study, rats were exposed whole-body to 50, 150 or 500 ppm (approximately 0.21, 0.64 or 2.13 mg/L/day) styrene vapor (see reference for details). In addition, a developmental neurotoxicity component was included to assess potential adverse functional and/or morphological effects in the F2 offspring following F0 and F1 generation exposures. No adverse exposure-related effects on survival or clinical observations were noted at any exposure level in the F0 or F1 generations. There were no indications of adverse effects on reproductive performance in either the F0 or F1 generations. No adverse exposure-related macroscopic pathology was noted at any exposure level in the F0 or F1 generations. (8EHQ-0803-15197) NOAEC (reproductive toxicity) = 500 ppm (~2.13 mg/L/day; highest concentration tested) (3) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=421&tid=74 Naphthalene (CASRN 91-20-3, supporting chemical) (1) No specific reproductive toxicity studies are available. However, in the 13-week oral repeated-dose studies in rats and mice, and the two-year inhalation carcinogenicity studies in rats and mice, no effects or histopathological changes were observed on the reproductive organs.

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(2) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx, http://www.epa.gov/iris/subst/0436.htm, http://ecb.jrc.ec.europa.eu/esis/ and http://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=240&tid=43. Dicyclopentadiene (CASRN 77-73-6, supporting chemical) In the combined oral repeated-dose/reproductive/developmental toxicity screening test in rats, no effects on reproductive parameters were observed up to the highest dose tested. However, two dams in the 100 mg/kg-day group did not nurse their litters and lost all of them within 2 days. See human health data at: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=c1669b2f-fe19-4ff0-8761-4d0e436e73e2&idx=0. NOAEL (reproductive toxicity) = 100 mg/kg-day (highest dose tested) Subcategory II: High Benzene Naphthas See data for CASRNs 78-79-5, 109-66-0, 110-54-3, 71-43-2, 108-88-3, 1330-20-7, 100-42-5 and 77-73-6 above. Subcategory III: Quench/Compressor Oil See data for CASRNs 71-43-2, 108-88-3, 1330-20-7, 100-42-5, 91-20-3 and 77-73-6 above. Developmental Toxicity Subcategory I: Pygas Rerun Tower Overheads (CASRN 64741-74-8, supporting chemical) Pregnant New Zealand White rabbits (16/dose) were administered the rerun tower overhead mixture orally via gavage at doses of 0, 10, 25 and 50 mg/kg/day from days 6-28 of gestation (NOTE: In an initial study that began with this protocol, 42 rabbits died – 14, 11, 13, and 13 in the 0, low, mid and high dose groups. Thus, the study was terminated and a new study was started). The only maternal effects noted were matted hair coat in the nasal region and a reduction in fecal material beneath cages (both in the high dose group only). One animal in the high dose group aborted. Most developmental parameters showed no treatment related effects: pregnancy ratios (two controls and one high dose animal had all resorptions); number of copora lutea, total implantations, early/late resorptions; post-implantation loss; viable fetuses, fetal sex index, fetal body weight; malformations (exceptions: one occurrence of atlas-occipital anomaly and one occurrence of enlarged heart with great vessel anomaly – each in separate litters). NOAEL (maternal/developmental toxicity) = 50 mg/kg/day (highest dose tested) Isoprene (CASRN 78-79-5, supporting chemical) In prenatal inhalation developmental toxicity studies in rats and mice, isoprene did not produce any maternal or developmental toxicity in rats following exposure to concentrations as high as 7000 ppm/day (~ 19.5 mg/L/day). In mice, maternal weight gain and uterine weight were significantly reduced at 7000 ppm/day (~ 19.5 mg/L/day). Significant reductions in fetal bodyweight were observed at 280 ppm in female fetuses (lowest concentration tested). See human health data at: http://www.chem.unep.ch/irptc/sids/OECDSIDS/78795.pdf Rat NOAEC (maternal/developmental toxicity) = 7000 ppm/day (~ 19.5 mg/L/day; highest concentration tested)

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Mouse LOAEC (maternal toxicity) = 7000 ppm/day (~ 19.5 mg/L/day; based on reduced maternal weight gain and uterine weight) Mouse NOAEC (maternal toxicity) = 1400 ppm/day (~ 3.9 mg/L/day) Mouse LOAEC (developmental toxicity) = 280 ppm/day (~ 1 mg/L/day; based on reductions in fetal bodyweight) Mouse NOAEC (developmental toxicity) = Not established Pentane (CASRN 109-66-0, supporting chemical) In a prenatal oral developmental toxicity study, pregnant Crl:CDBR rats were treated with 100, 500 or 1000 mg/kg/day n-pentane on days 6-15 of gestation. There was no mortality or statistically significant differences in mean body weight, body weight change, uterine weight, corrected body weight, or uterine implantation data between treated and control dams at any dose. There was no evidence of growth retardation or increased fetal death at any dose. There were no statistically significant differences in total or individual variations or malformations. (CASRN 109-66-0: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=0af02fa3-f3ef-4df9-b050-43116efd8ef1&idx=0 and C5 aliphatic hydrocarbon solvents category - http://webnet.oecd.org/hpv/ui/Search.aspx). NOAEL (maternal toxicity) = 1000 mg/kg/day (highest dose tested) NOAEL (developmental toxicity) = 1000 mg/kg/day (highest dose tested) Hexane (CASRN 110-54-3, supporting chemical) See human health data summarized in EPA IRIS assessment: http://www.epa.gov/iris/toxreviews/0486tr.pdf Benzene (CASRN 71-43-2, supporting chemical) (1) Pregnant Swiss-Webster Crl:CFW(SW)Br mice (15/dose) were exposed to benzene as a vapor at 0, 5, 10 or 20 ppm (approximately 0, 0.016, 0.032 or 0.064 mg/L), 6 hours/day on gestation days 6 – 15. Mice (5/dose) were sacrificed on gestation day 16. Endpoints included the numbers of live, dead and resorbed fetuses, fetal weights and external gross morphological malformations, RBC and WBC counts and hemoglobin analysis of fetal blood and numbers of cells in the hematopoietic differentiating proliferating pool (DPP) of fetal livers. Additional mice (5/dose) were allowed to proceed through normal parturition and on day 2 postpartum, pups were subjected to hematological examination, as above. The remaining mice (5/dose) were allowed to proceed through normal parturition and after 6 weeks postpartum, peripheral blood samples were removed from offspring for RBC and WBC counts; additionally, cells of the DPP were enumerated in the spleen and femoral bone marrow. No mortality, morbidity or weight loss of dams was observed during the exposure. No effects of exposure were observed on litter sizes, sex ratios, pup weights and numbers of dead, resorbed or malformed fetuses. Reduced counts of erythroid precursor cells (early nucleated cells) were observed in the peripheral blood of 2-day old pups exposed to benzene (concentrations not specified). Depressed numbers of late nucleated red cells and elevated numbers of granulocytic precursor cells (non-dividing granulocytes) were observed in the peripheral blood of 2-day old pups exposed to 0.064 mg/L. Lower numbers of early and late nucleated RBCs were observed in the livers of 2-day old pups at 0.064 mg/L. Elevated numbers of blasts, dividing/non-dividing granulocytes and lymphocytes were observed in the livers of 2-day old pups and spleens and femurs of 6-week old offspring of dams exposed to 0.064 mg/L. NOAEC (maternal toxicity) ~ 0.064 mg/L/day (highest concentration tested)

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LOAEC (developmental toxicity) ~ 0.064 mg/L/day (based on effects on the hematopoietic system) NOAEC (developmental toxicity) ~ 0.032 mg/L/day (2) In a modified prenatal developmental toxicity study, female Sprague-Dawley rats (26 /dose) were exposed to benzene as a vapor at 0, 1, 30 or 300 ppm (approximately 0, 0.0032, 0.096 or 0.96 mg/L), 6 hours/day, 5 days/week for a 10-week pre-mating and mating period and daily on gestation days 0 – 20 and lactation days 5 – 20. Endpoints included maternal body weight, pregnancy rate, length of gestation, numbers of live and dead pups, sex ratio, pup survival, pup body weight change and pup organ weights. Reduced body and liver weights were observed in female pups at 0.96 mg/L. [EPA’s Toxicological Review of Benzene, 2002 (EPA/635/R-02/001F)]. NOAEC (maternal toxicity) ~ 0.96 mg/L/day (highest concentration tested) LOAEC (developmental toxicity) ~ 0.96 mg/L/day (based on reduced body and liver weights in female pups) NOAEC (developmental toxicity) ~ 0.096 mg/L/day (3) See human health data at: http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/benzenereport063.pdf. Toluene (CASRN 108-88-3, supporting chemical) Generally, rat inhalation studies provide strong evidence of developmental toxicity (lower birth weight and long-lasting developmental neurotoxicity) in the absence of maternal toxicity. See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://www.epa.gov/oppt/vccep/pubs/chem13a.html In the two-generation inhalation reproductive toxicity study in rats, described above, effects on the development of fetuses and/or pups were observed in both generations. NOAEC (maternal toxicity) = 2000 ppm/day (~7.5 mg/L/day; highest concentration tested) LOAEC (developmental toxicity) = 1000 ppm/day (~ 3.8 mg/L/day; based on decreased fetal growth and pup weight and delayed ossification in F1 and F2 offspring) NOAEC (developmental toxicity) = 600 ppm/day (~ 2.3 mg/L/day) Xylenes, mixed (CASRN 1330-20-7, supporting chemical) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=296&tid=53. (1) In a prenatal developmental toxicity study, rats were exposed to mixed xylenes via inhation up to 2000 ppm/day (approximately 8.8 mg/L/day) on gestation days 6-20. Dams showed decreased body weight, body weight gain and reduced food consumption at 1000 ppm/day and above. Developmental effects included decreased fetal body weight at 500 ppm. Skeletal variations were increased at 2000 ppm. LOAEC (maternal toxicity) = 1000 ppm/day (~ 4.4 mg/L/day) (based on decreased body weight, weight gain and food consumption) NOAEC (maternal toxicity) = 500 ppm/day (~ 2.2 mg/L/day) LOAEC (developmental toxicity) = 500 ppm/day (~ 2.2 mg/L/day) (based on decreased fetal body weight)

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NOAEC (developmental toxicity) = 100 ppm/day (~ 0.44 mg/L/day) (2) In a developmental neurotoxicity study, rats exposed via inhalation to mixed xylenes on days 4-20 gestation showed impaired performance in a motor ability test. LOAEC (developmental neurotoxicity) = 200 ppm/day (~ 0.88 mg/L/day) (based on impaired motor ability) NOAEC (developmental toxicity) < 200 ppm/day (<~ 0.88 mg/L/day) Styrene (CASRN 100-42-5) (1) In the two-generation reproductive toxicity study described above, clear developmental findings were limited to treatment-related reductions in mean body weights of the F1 and F2 offspring at 150 ppm and above. Similarly, body weight decreases were observed for all animals in the mid- and high-dose groups. An overall pattern of delay was evident in the F2 offspring at the high dose and included both statistically significant and non-significant changes (e.g. reduced body weight, delayed appearance of some physical landmarks of development). There were no other alterations in behavioral performance parameters or in brain weight, histology or morphometry to suggest that selective developmental neurotoxicity occurred. LOAEC (maternal toxicity) = 150 ppm/day (~0.64 mg/L/day) (based on decreased body weight) NOAEC (maternal toxicity) = 50 ppm/day (~0.21 mg/L/day) LOAEC (developmental toxicity) = 150 ppm/day (~0.64 mg/L/day) (based on decreased fetal body weight and delayed development) NOAEC (developmental toxicity) = 50 ppm/day (~0.21 mg/L/day) NOAEC (developmental neurotoxicity) = 500 ppm/day (~2.13 mg/L/day) (highest concentration tested) (2) See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=421&tid=74 Dicyclopentadiene (CASRN 77-73-6, supporting chemical) In the combined oral repeated-dose/reproductive/developmental toxicity screening test in rats, no abnormal findings attributed to the test substance were found for external features, clinical signs or on necropsy of offspring. See human health data at: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=c1669b2f-fe19-4ff0-8761-4d0e436e73e2&idx=0. LOAEL (maternal toxicity) = 100 mg/kg-day (based on decreased body weight) NOAEL (maternal toxicity) = 20 mg/kg-day NOAEL (developmental toxicity) = 100 mg/kg-day (highest dose tested) Subcategory II: High Benzene Naphthas See data for CASRNs 78-79-5, 109-66-0, 110-54-3, 71-43-2, 108-88-3, 1330-20-7, 100-42-5 and 77-73-6 above. Subcategory III: Quench/Compressor Oil See data for CASRNs 71-43-2, 108-88-3, 1330-20-7, 100-42-5 and 77-73-6 above.

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Genetic Toxicity – Gene Mutation In vitro Subcategory I: Pygas Rerun Tower Overheads (CASRN 64741-74-8, supporting chemical) (1) Salmonella typhimurium strains TA98, TA100, TA1535, TA1537 and TA1538 were exposed to the rerun tower overhead mixture (see Table II.2 in Appendix II for component identification) diluted in dimethyl sulfoxide (DMSO) at concentrations of 0 (untreated control), 0.029, 0.094, 0.30 and 0.97 ul/plate (without S9) and 0, 0.30, 0.97 and 3.1 ul/plate (with S9). Preliminary testing showed cytotoxicity at 10 ul/plate (with S9) and above 3.1 ul/plate (without S9). Rerun tower ovreheads did not induce increases in the number of revertant colonies in any Salmonella strain. Positive controls were tested and performed appropriately. Rerun tower overhead mixture was not mutagenic in this assay. (2) In a mammalian cell mutation assay, mouse lymphoma cells (L5178Y TK +/-) were exposed to the rerun tower overhead mixture (see Table II.2 in Appendix II for component identification) at eight concentrations ranging from 0 – 0.10 ug/mL (without S9) and to eight concentrations ranging from 0 – 0.36 ul/mL (with S9). The induced mutation frequency (IMF) (mutation frequency of test substance minus the mutation frequency of the control) showed slight increases at the two highest concentrations for the cells exposed to the rerun tower overhead mixture without metabolic activation (IMFs of 0.4 and 0.8). A similar weak response was seen in two concentrations for cells exposed to the test mixture with metabolic activation; but it was not dose-related (i.e., they were the fourth highest [IMF of 0.9] and the highest [IMF of 0.4]). In all cases the IMFs were much lower than the positive control values (i.e., IMF of ~26 without activation and IMF of ~2.3 with activation). Rerun tower overhead mixture was weakly mutagenic (without metabolic activation) and not mutagenic (with activation) in this assay Isoprene (CASRN 78-79-5, supporting chemical) See human health data at: http://www.chem.unep.ch/irptc/sids/OECDSIDS/78795.pdf Isoprene did not induce gene mutations in these assays. Pentane (CASRN 109-66-0, supporting chemical) (1) In a reverse-mutation assay, Salmonella typhimurium strains TA97, TA98, TA100 and TA1535 were exposed to pentane in dimethylsulfoxide (DMSO) at concentrations up to 6667 µg/plate with and without metabolic activation. Positive and negative controls were tested concurrently and responded appropriately. Cytotoxicity was observed at concentrations ≥ 100 µg/plate for all strains with and without activation. Pentane did not cause an increase in mutation frequency in any strain with or without activation (NTP study 502864: http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchhome). Pentane was not mutagenic in this assay. (2) See human health data for CASRN 109-66-0: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=0af02fa3-f3ef-4df9-b050-

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43116efd8ef1&idx=0 and C5 aliphatic hydrocarbon solvents category - http://webnet.oecd.org/hpv/ui/Search.aspx. Hexane (CASRN 110-54-3, supporting chemical) See human health data summarized in EPA IRIS assessment: http://www.epa.gov/iris/toxreviews/0486tr.pdf Hexane was not mutagenic in these assays. Benzene (CASRN 71-43-2, supporting chemical) (1) Salmonella typhimurium strains TA98, TA100, TA104 and TA1535 were exposed to benzene as a vapor at concentrations of 0, 3, 6, 15, 30, 100, 300 or 1000 ppm with and without metabolic activation. A positive control was not used. Exposure to benzene increased the mutation frequency in TA100, TA104 and TA1535 with activation. Cytotoxicity was not specified. Benzene was mutagenic in this assay. (2) See human health data at: http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/benzenereport063.pdf. Toluene (CASRN 108-88-3, supporting chemical) Toluene has been tested for mutagenicity in several assays. See human health data at: http://ecb.jrc.ec.europa.eu/esis/index CASRN 108-88-3 was not considered mutagenic. Xylenes, mixed (CASRN 1330-20-7, supporting chemical) (1) Mouse lymphoma cells were exposed to mixed xylenes at doses of 0, 5.6-87.0 μg/ml with or without metabolic activation, no mutational events were induced. CASRN 1330-20-7 was not mutagenic in this assay. (2) Sister chromatid exchange (SCE) or chromosome aberrations were not observed in Chinese hamster ovary cells with or without activation or in cultured human lymphocytes that retain endogenous metabolic activity. CASRN 1330-20-7 was not mutagenic in this assay. (3) See human health data at: http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=296&tid=53. Styrene (CASRN 100-42-5, supporting chemical) Styrene is not genotoxic in the vast majority of in vitro standard mutagenicity tests. See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://ec.europa.eu/health/ph_risk/committees/04_scher/docs/scher_o_095.pdf CASRN 100-42-5 was not considered mutagenic. Naphthalene (CASRN 91-20-3, supporting chemical) See human health data at: http://ecb.jrc.ec.europa.eu/esis/ CASRN 91-20-3 was not mutagenic in these assays. Dicyclopentadiene (CASRN 77-73-6, supporting chemical) In a reverse mutation assay in bacteria with and without metabolic activation, CASRN 77-73-6 was not mutagenice. See human health data at:

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http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=c1669b2f-fe19-4ff0-8761-4d0e436e73e2&idx=0. CASRN 77-73-6 was not mutagenic in this assay. Subcategory II: High Benzene Naphthas See data for CASRNs 78-79-5, 109-66-0, 110-54-3, 71-43-2, 108-88-3, 1330-20-7, 100-42-5 and 77-73-6 above. Hydrogenated pyrolysis gasoline (CASRN 68410-97-9, Hydrotreated C6 – C8 Fraction) Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537 and Escherichia coli WP2(uvrA) were exposed to hydrogenated pyrolysis gasoline diluted in acetone at concentrations of 0 (untreated control), 33, 100, 333, 1000, 3333 or 10,000 µg/plate in the presence and absence of 20% S9 metabolic activation. Hydrogenated pyrolysis gasoline did not induce increases in number of revertant colonies and no toxicity was observed in any Salmonella strain or Escherichia coli WP2 with or without 20% S9 metabolic activation. Positive controls were tested and performed appropriately. CASRN 68410-97-9 was not mutagenic in this assay. Subcategory III: Quench/Compressor Oil See data for CASRNs 71-43-2, 108-88-3, 1330-20-7, 100-42-5 and 77-73-6 above. Genetic Toxicity – Chromosomal Aberrations In vitro Subcategory I: Pygas Isoprene (CASRN 78-79-5, supporting chemical) See human health data at: http://www.chem.unep.ch/irptc/sids/OECDSIDS/78795.pdf Isoprene did not induce chromosomal aberrations in these assays. Pentane (CASRN 109-66-0, supporting chemical) Chinese hamster ovary cells were treated with pentane with and without metabolic activation. The results obtained were inconclusive (See human health data for CASRN 109-66-0: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=0af02fa3-f3ef-4df9-b050-43116efd8ef1&idx=0 and C5 aliphatic hydrocarbon solvents category - http://webnet.oecd.org/hpv/ui/Search.aspx). Pentane was equivocal for chromosomal aberrations in this assay. Hexane (CASRN 110-54-3, supporting chemical) See human health data summarized in EPA IRIS assessment: http://www.epa.gov/iris/toxreviews/0486tr.pdf Hexane did not induce chromosomal aberrations in these assays. Benzene (CASRN 71-43-2, supporting chemical) (1) Human lymphocytes were exposed to benzene at concentrations of 16, 78 or 391 mg/L with or without metabolic activation. Increases in the frequency of sister chromatid exchange and cytotoxicity were observed with activation. No positive control was used. Benzene induced sister chromatid exchange in this assay.

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(2) See human health data at: http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/benzenereport063.pdf. Toluene (CASRN 108-88-3, supporting chemical) Toluene has been tested for genotoxicity in several assays. See human health data at: http://ecb.jrc.ec.europa.eu/esis/index CASRN 108-88-3 did not induce chromosomal aberrations in these assays. Xylenes, mixed (CASRN 1330-20-7, supporting chemical) See human health data at: http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=296&tid=53. CASRN 1330-20-7 did not induce chromosomal aberrations in these assays. Styrene (CASRN 100-42-5, supporting chemical) Styrene tested positive for SCEs, DNA strand breaks and DNA adducts in vitro. See human health data at: http://webnet.oecd.org/hpv/UI/Search.aspx and http://ec.europa.eu/health/ph_risk/committees/04_scher/docs/scher_o_095.pdf CASRN 100-42-5 induced chromosomal aberrations in these assays. Naphthalene (CASRN 91-20-3, supporting chemical) Naphthalene has been tested in Chinese Hamster Ovary (CHO) cells and in sister chromatid exchange assays. See human health data at: http://ecb.jrc.ec.europa.eu/esis/ CASRN 91-20-3 induced chromosomal aberrations in these assays. Dicyclopentadiene (CASRN 77-73-6, supporting chemical) In Chinese hamster lung (CHL/IU) cells treated with CASRN 77-73-6 with and without metabolic activation, structural chromosomal aberrations were marginally induced at 0.057 mg/mL after 24-h continuous treatment. However, the documents state that the test substance did not induce structural chromosomal aberrations or polyploidy in CHL/IU cells up to a concentration causing more than 50% cell growth inhibition. See human health data at: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=c1669b2f-fe19-4ff0-8761-4d0e436e73e2&idx=0. CASRN 77-73-6 was not considered to induce chromosomal aberrations in this assay. Subcategory II: High Benzene Naphthas See data for CASRNs 78-79-5, 109-66-0, 110-54-3, 71-43-2, 108-88-3, 1330-20-7, 100-42-5 and 77-73-6 above. Subcategory III: Quench/Compressor Oil See data for CASRNs 71-43-2, 108-88-3, 1330-20-7, 100-42-5 and 77-73-6 above. Genetic Toxicity – Chromosomal Aberrations In vivo Subcategory I: Pygas Isoprene (CASRN 78-79-5, supporting chemical) See human health data at: http://www.chem.unep.ch/irptc/sids/OECDSIDS/78795.pdf

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Isoprene induced mouse micronuclei in these assays. Pentane (CASRN 109-66-0, supporting chemical) In a micronecleus assay, rats were treated with pentane via inhalation and bone marrow micronuclei examined (See human health data for CASRN 109-66-0: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=0af02fa3-f3ef-4df9-b050-43116efd8ef1&idx=0 and C5 aliphatic hydrocarbon solvents category - http://webnet.oecd.org/hpv/ui/Search.aspx). Pentane did not induce micronuclei in this assay. Hexane (CASRN 110-54-3, supporting chemical) When tested in vivo, hexane is predominantly negative for genotoxicity. However, it has tested positive in mouse micronucleus assays in vivo. See human health data summarized in EPA IRIS assessment: http://www.epa.gov/iris/toxreviews/0486tr.pdf Hexane did induced micronuclei in these assays. Benzene (CASRN 71-43-2, supporting chemical) (1) In a sister chromatid exchange assay, male Sprague-Dawley rats (5/dose) were exposed to benzene as a vapor at 0, 0.1, 0.3, 1, 3, 10 or 30 ppm for 6 hours. Upon sacrifice, lymphocytes were assayed for sister chromatid exchange. The use of a positive control was not specified. At doses ≥ 3 ppm, a dose-dependent increase in the frequency of sister chromatid exchange was observed. Benzene induced sister chromatid exchange in this assay. (2) In a micronucleus assay, male Sprague-Dawley rats (5/dose) were exposed to benzene as a vapor at 0, 0.1, 0.3, 1, 3, 10 or 30 ppm for 6 hours. The use of a positive control was not specified. Significant increases in the frequency of micronuclei were observed at doses ≥ 1 ppm. Benzene induced micronuclei in this assay. (3) In a sister chromatid exchange assay, male DBA/2 mice (5/dose) were exposed to benzene as a vapor at 0, 10, 100 or 1000 ppm for 6 hours; upon sacrifice, lymphocytes were assayed for sister chromatid exchange. The use of a positive control was not specified. Increases in the frequency of sister chromatid exchange were observed at all doses. Benzene induced sister chromatid exchange in this assay. (4) In a micronucleus assay, male DBA/2 mice (5/dose) were exposed to benzene as a vapor at 0, 10, 100 or 1000 ppm for 6 hours. The use of a positive control was not specified. Significant increases in the frequency of micronuclei were observed at all doses. Benzene induced micronuclei in this assay. Toluene (CASRN 108-88-3, supporting chemical) Toluene has been tested for genotoxicity in several assays. See human health data at: http://ecb.jrc.ec.europa.eu/esis/index CASRN 108-88-3 did not induce chromosomal aberrations in these assays. Xylenes, mixed (CASRN 1330-20-7, supporting chemical)

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Mouse lymphoma cells were exposed to mixed xylenes at doses of 0, 5.6-87.0 μg/mL with or without metabolic activation, no mutational events were induced. See human health data at: http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=296&tid=53. CASRN 1330-20-7 did not induce chromosomal aberrations in this assay. Styrene (CASRN 100-42-5, supporting chemical) See human health data at: http://ecb.jrc.ec.europa.eu/esis/ CASRN 100-42-5 did not induce chromosomal aberrations in vivo. Naphthalene (CASRN 91-20-3, supporting chemical) See human health data at: http://ecb.jrc.ec.europa.eu/esis/ CASRN 91-20-3 did not induce micronuclei these assays. Subcategory II: High Benzene Naphthas See data for CASRNs 78-79-5, 109-66-0, 110-54-3, 71-43-2, 108-88-3, 1330-20-7 and 100-42-5 above. Hydrogenated pyrolysis gasoline (CASRN 68410-97-9, Hydrotreated C6 – C8 Fraction) In a mammalian bone marrow erythrocyte micronucleus assay, Crl:CD-1(ICR)BR Swiss mice (10 – 15/sex/dose) were administered hydrogenated pyrolysis gasoline by gavage at concentrations of 500, 1000 or 2000 mg/kg/day for 2 days. Negative controls were given corn oil (vehicle). One male given 2000 mg/kg died on day 2. Half the animals were sacrificed 24 hours after the last dose and the other half 48 hours after the last dose. Positive and negative controls gave appropriate responses. None of the surviving mice exhibited increased micronucleus formation. CASRN 68410-97-9 did not increase the frequency of micronucleated PCEs in bone marrow in this assay. Subcategory III: Quench/Compressor Oil See data for CASRNs 71-43-2, 108-88-3, 1330-20-7, 91-20-3 and 100-42-5. Genetic Toxicity – Other In vitro Subcategory I: Pygas Rerun Tower Overheads (CASRN 64741-74-8, supporting chemical) Salmonella typhimurium strains TA1978 uvrB+, TA1538 uvrB- and Escherichia coli WP2 (uvrA+ recA+) and WP100 (uvrA- recA-) were exposed to the rerun tower overhead mixture (see Table II.2 in Appendix II for component identification) at a single concentration of 10ul/plate (spot test), both with and without metabolic activation. The test was designed to determine general damage to DNA by evaluating whether a chemical is more toxic to DNA-repair deficient bacteria compared to DNA-repair efficient bacteria. Positive and negative controls were used and responded appropriately. Results indicated that the test mixture was weakly positive via differential killing of DNA repair deficient bacteria (without metabolic activation), but not with metabolic activation.

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Subcategory II: High Benzene Naphthas Hydrogenated pyrolysis gasoline (CASRN 68410-97-9, C6 – C8 Fraction) In an unscheduled DNA synthesis (UDS) assay, rat primary hepatocytes were exposed to the test substance (diluted in 10% Pluronic F68) at concentrations of 8, 16, 32, 64, 128, 256, 512 or 1024 µg/mL. At the two highest concentrations, hydrogenated pyrolysis gasoline induced toxicity following 18 hr exposure that left too few cells for UDS analysis. Hydrogenated pyrolysis gasoline did not induce unscheduled DNA synthesis at non-cytotoxic concentrations (≤ 256 µg/mL). Positive and negative controls gave appropriate responses. CASRN 68410-97-9 was negative for induction of unscheduled DNA synthesis (UDS) in this assay (at concentrations ≤ 256 µg/mL). Additional Information Skin Irritation Pentane (CASRN 109-66-0, supporting chemical) See human health data for CASRN 109-66-0: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=0af02fa3-f3ef-4df9-b050-43116efd8ef1&idx=0 and C5 aliphatic hydrocarbon solvents category - http://webnet.oecd.org/hpv/ui/Search.aspx. Pentane was not a skin irritant in rabbits in this study. Toluene (CASRN 108-88-3, supporting chemical) See human health data at: http://ecb.jrc.ec.europa.eu/esis/index CASRN 108-88-3 is irritating to the skin. Xylenes, mixed (CASRN 1330-20-7, supporting chemical) See human health data at: http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=296&tid=53, http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=64572a9c-b517-4f0a-a9c0-8953539bf5c9&idx=0. CASRN 1330-20-7 is irritating to the skin. Styrene (CASRN 100-42-5, supporting chemical) See human health data at: http://ecb.jrc.ec.europa.eu/esis/ CASRN 100-42-5 is irritating to the skin. Naphthalene (CASRN 91-20-3, supporting chemical) See human health data at: http://ecb.jrc.ec.europa.eu/esis/ CASRN 91-20-3 is irritating to the skin. Dicyclopentadiene (CASRN 77-73-6, supporting chemical) Three New Zealand White rabbits (sex not reported) were administered CASRN 77-73-6 (75% pure; 0.5 mL) to clipped skin for 4 hours under semi-occlusive conditions and observed for 14 days. Well-defined erythema was observed within 3 days of exposure in all animals. Signs of keratinization were observed on day 7. Moderate edema was observed at 24 hours in all animals, and regressed to slight by day 3. The primary irritation index was 4.7. These data are summarized in TSCATS OTS0558246. CASRN 77-73-6 was moderately irritating to rabbit skin in this study.

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Eye Irritation Subcategory I: Pygas Pentane (CASRN 109-66-0, supporting chemical) See human health data for CASRN 109-66-0: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=0af02fa3-f3ef-4df9-b050-43116efd8ef1&idx=0 and C5 aliphatic hydrocarbon solvents category - http://webnet.oecd.org/hpv/ui/Search.aspx. Pentane was minimally irritating to rabbit eyes in this study. Toluene (CASRN 108-88-3, supporting chemical) See human health data at: http://ecb.jrc.ec.europa.eu/esis/index CASRN 108-88-3 is irritating to the eye. Xylenes, mixed (CASRN 1330-20-7, supporting chemical) See human health data at: http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=296&tid=53, http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=64572a9c-b517-4f0a-a9c0-8953539bf5c9&idx=0. CASRN 1330-20-7 is irritating to the eye. Dicyclopentadiene (CASRN 77-73-6, supporting chemical) Three New Zealand White rabbits (sex not reported) were instilled with 0.1 mL of CASRN 77-73-6 (75% pure) into the eyes. A dulling of the corneal surface, iridial inflammation and moderate conjunctival irritation were observed. The test material produced a group mean score of 18.3. These data are summarized in TSCATS OTS0558243-1. CASRN 77-73-6 was moderately irritating to rabbit eyes in this study. Respiratory Tract Irritation Pentane (CASRN 109-66-0, supporting chemical) See human health data for CASRN 109-66-0: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=0af02fa3-f3ef-4df9-b050-43116efd8ef1&idx=0 and C5 aliphatic hydrocarbon solvents category - http://webnet.oecd.org/hpv/ui/Search.aspx. Pentane was not a respiratory tract irritant in mice in this study. Skin Sensitization Pentane (CASRN 109-66-0, supporting chemical) See human health data for CASRN 109-66-0: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=0af02fa3-f3ef-4df9-b050-43116efd8ef1&idx=0 and C5 aliphatic hydrocarbon solvents category - http://webnet.oecd.org/hpv/ui/Search.aspx. Pentane was not sensitizing to guinea pig skin in this study.

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Toluene (CASRN 108-88-3, supporting chemical) See human health data at: http://ecb.jrc.ec.europa.eu/esis/index CASRN 108-88-3 is negative in skin sensitization assays. Styrene (CASRN 100-42-5, supporting chemical) See human health data at: http://ecb.jrc.ec.europa.eu/esis/ CASRN 100-42-5 is negative in skin sensitization assays. Naphthalene (CASRN 91-20-3, supporting chemical) See human health data at: http://ecb.jrc.ec.europa.eu/esis/ CASRN 91-20-3 is negative in skin sensitization assays. Carcinogenicity Benzene (CASRN 71-43-2, supporting chemical) (1) In a NTP study, haploinsufficient p16Ink4a/p19Arf mice (15/sex/dose) were administered benzene in corn oil via gavage at 0, 25, 50, 100 or 200 mg/kg-bw, 5 days/week for 27 weeks. The incidence of malignant lymphoma was significantly increased in males at 200 mg/kg-bw. [Details were obtained from NTP study C99034: http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchhome]. Benzene was carcinogenic to mice in this study. (2) In an NTP study, F344/N rats (50/sex/dose) were administered benzene in corn oil via gavage at 0, 25, 50 or 100 mg/kg-bw, 5 days/week for 103 weeks. Treatment-related increases were observed in the incidences of Zymbal gland carcinomas, squamous cell papillomas and carcinomas of the oral cavity and squamous cell papillomas and carcinomas of the skin (males only). [Details were obtained from NTP study C55276: http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchhome]. Benzene was carcinogenic to rats in this study. (3) In an NTP study, B6C3F1 mice (50/sex/dose) were administered benzene in corn oil via gavage at 0, 25 (females only), 50, 100 or 200 (males only) mg/kg-bw, 5 days/week for 103 weeks. Exposure to benzene increased the incidences of Zymbal gland squamous cell carcinomas, malignant lymphomas, alveolar/bronchiolar carcinomas, squamous cell carcinomas of the preputial gland, ovarian granulosa cell tumors and carcinomas and carcinosarcomas of the mammary gland. [Details were obtained from NTP study C55276: http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchhome]. Benzene was carcinogenic to mice in this study. (4) Benzene is characterized as a known human carcinogen for all routes of exposure based upon convincing human evidence as well as supporting evidence from animal studies (http://www.epa.gov/ncea/iris/subst/0276.htm). Toluene (CASRN 108-88-3, supporting chemical) Toluene has been evaluated for carcinogenicity via the inhalation route of exposure in rats and mice. The rat study was negative and non-malignant tumors were observed in the pituitary gland in mice. In a skin painting study in mice, malignant skin tumors occurred at concentrations

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causing skin irritation; however, the effects were not considered statistically significant. See human health data at: http://ecb.jrc.ec.europa.eu/esis/index CASRN 108-88-3 is not considered to be carcinogenic. Xylenes, mixed (CASRN 1330-20-7, supporting chemical) Mixed xylenes has been evaluated for carcinogenicity via the oral route in rats and mice. There was no increased incidence of tumors in either specie. See human health data at: http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=296&tid=53, http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=64572a9c-b517-4f0a-a9c0-8953539bf5c9&idx=0. CASRN 1330-20-7 is negative in carcinogenicity studies. Styrene (CASRN 100-42-5, supporting chemical) An agreement on the interpretation of available information on the genotoxicity and carcinogenicity of styrene was not made at SIAM (1996; http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=96240163-414e-4da4-8f1f-82dce4c16be2&idx=0). The National Toxicology Program (NTP) found that styrene was negative for carcinogenicity in rats and female mice (oral route) but there was an increased incidence of lung adenomas and carcinomas in male mice, which was considered equivocal (http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=abstracts.abstract&chemical_name=Styrene&cas_no=100-42-5&study_no=C02200A&study_length=2%20Years&abstract_url=07059C3F-BEA9-487F-F6B78FB485DFE06F&next=longtermbioassaydata.datasearch). The carcinogenic potential of styrene has not been evaluated by EPA and DHHS (http://www.epa.gov/iris/subst/0104.htm and http://www.atsdr.cdc.gov/ToxProfiles/tp53.pdf) CASRN 100-42-5 shows increased incidence of tumors in mice but not rats. Naphthalene (CASRN 91-20-3, supporting chemical) Naphthalene has been evaluated for carcinogenicity via the inhalation route in mice. A statistically significant tumorigenic response was found in female B6C3F1 mice. See human health data at: http://ecb.jrc.ec.europa.eu/esis/ and http://www.epa.gov/iris/toxreviews/0436tr.pdf. CASRN 91-20-3 shows an increased incidence in tumors in female mice. Neurotoxicity Toluene (CASRN 108-88-3, supporting chemical) (1) See human health data at: http://ecb.jrc.ec.europa.eu/esis/index CASRN 108-88-3 is neurotoxic. (2) There is a considerable database on the effects of repeated exposure to styrene in humans (http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=e1315e8d-6a51-4a59-b4da-a3d24baade0d&idx=0). See human health data at: http://www.epa.gov/iris/subst/0118.htm and http://www.epa.gov/oppt/vccep/pubs/chem13a.html.

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LOAEC = 132 ppm (~ 0.5 mg/L/day) (based on neurological effects in occupationally exposed workers) NOAEC = 32 ppm (~ 0.12 mg/L/day) Xylenes, mixed (CASRN 1330-20-7, supporting chemical) (1) Signs of neurotoxicity observed in rats, mice, dogs, cats, and gerbils following acute and intermediate inhalation and gavage exposure to the various xylene isomers include narcosis, prostration, incoordination, tremors, muscular spasms, labored breathing, behavioral changes, hyperreactivity to stimuli, altered visual evoked potentials, elevated auditory thresholds, hearing loss, and decreased acetylcholine in midbrain and norepinephrine in hypothalamus. See human health data at: http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=296&tid=53. CASRN 1330-20-7 is neurotoxic. (2) See human health data at: http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=296&tid=53. LOAEC = 14 ppm (used to derive a chronic-duration minimal risk level (MRL) for mixed xylenes) CASRN 1330-20-7 increased prevalence of anxiety, forgetfulness, inability to concentrate and other subjective symptoms in chronically exposed humans. Styrene (CASRN 100-42-5, supporting chemical) (1) Neurotoxicity is a key issue with styrene; however, no agreement was reached at SIAM on the interpretation of neurotoxicity studies (1996; http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=96240163-414e-4da4-8f1f-82dce4c16be2&idx=0). (2) In the workplace, irritation is reported at styrene levels exceeding 0.105 mg/L. CNS depression is reported in workers exposed to styrene. Styrene-induced symptoms of acute CNS depression (similar to those observed with many solvents) include drowsiness, dizziness, headache, and impaired balance. See human health data at: http://ecb.jrc.ec.europa.eu/esis/ LOAEC >100 ppm (~ 0.43 mg/L) NOAEC ≤ 100 ppm (~0.43 mg/L) (3) See human health data at: http://www.epa.gov/iris/subst/0104.htm and http://www.atsdr.cdc.gov/ToxProfiles/tp53.pdf CASRN 100-42-5 is neurotoxic. Dicyclopentadiene (CASRN 77-73-6, supporting chemical) (1) In the acute inhalation toxicity study in rats described above, rats of both sexes exposed to 3.01 mg/L exhibited signs of neurotoxicity including loss of righting reflex, impaired gait and convulsions immediately prior to death. Stereotypic behavior and respiratory difficulty were observed in both sexes exposed to 1.41 mg/L and sluggish movement was noted in both sexes exposed to 0.7 mg/L. Convulsions were observed immediately before death in animals that died from exposure. All surviving animals fully recovered from clinical effects by day 2. No signs of neurotoxicity were noted at the lowest test concentration. CASRN 77-73-6 was neurotoxic to rats in this study.

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(2) In the acute inhalation toxicity study in mice described above, mice of both sexes exhibited signs of neurotoxicity including loss of righting reflex at 3.01 mg/L, impaired gait and loss of coordination at ≥ 1.41 mg/L and stereotypic behavior and respiratory difficulty at ≥0.7 mg/L. Females also exhibited loss of coordination and slight tremors at 0.7 mg/L. Convulsions were observed immediately before death in animals that died from exposure. No signs of neurotoxicity were noted at the lowest exposure concentration. CASRN 77-73-6 was neurotoxic to mice in this study.

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Table 9. Summary of Screening Information Data set Under the U.S. HPV Challenge Program – Human Health Data1

Subcategory I4 Subcategory II5 Subcategory III6

Endpoints SPONSORED CHEMICAL

Pyrolysis gasoline

(Dripolene)a

(No CASRN)

SPONSOREDCHEMICALRecovered

oil from wastewater

(No CASRN)

SPONSORED CHEMICAL Pyrolysis C6

fraction

(No CASRN)

SPONSORED CHEMICAL

Pyrolysis C6 – C8 fraction

(No CASRN)

SPONSORED CHEMICAL

Pyrolysis C5 – C6 fraction

(No CASRN)

SPONSORED CHEMICAL

Hydro-treated C6

fraction (No CASRN)

SPONSORED CHEMICAL

Hydro-treated C6 – C7 fraction

(No CASRN)

SPONSORED CHEMICAL Aromatic

extract from benzene

extraction (64741-99-7)

SPONSORED CHEMICAL

Hydro-treated C6 – C8 fraction

(68410-97-9)

SPONSORED CHEMICAL Quench loop pyrolysis oil

(69013-21-4) Acute Oral Toxicity LD50 (mg/kg)

> 2000

No Data > 2000 (RA)

No Data 5170 (RA)

No Data 5170 (RA)

No Data 5170 (RA)

No Data 5170 (RA)

No Data 5170 (RA)

No Data 5170 (RA)

5170

No Data2 590 – 8640

(RA)

Acute Inhalation Toxicity LC50 (ppm)

No Data 78 – 98,662

(RA)

No Data 78 – 98,662

(RA)

No Data > 12,408

(RA)

No Data > 12,408

(RA)

No Data > 12,408 (

(RA)

No Data > 12,408

(RA)

No Data > 12,408

(RA)

No Data > 12,408

(RA)

> 12,408

No Data2 1000-13,700 (RA)

Acute Dermal Toxicity LD50 (mg/kg)

> 2000

No Data > 2000 (RA)

– – – – – – – –

Repeated-Dose Toxicity3 NOAEL/LOAEL Oral (mg/kg-day)

No Data BMDL= 238

NOAEL = 4 - 500 LOAEL = 20 – 2000

(RA)

No Data BMDL= 238

NOAEL = 4 - 500 LOAEL = 20 – 2000

(RA)

No Data BMDL= 238 N= 4 - 250

L= 20 – 500 (RA)

Repeated-Dose Toxicity3 NOAEC/LOAEC Inhalation (ppm/day)

No Data BMCL= 2.6 - 61

NOAEC = 12 - 6600 LOAEC = 0.2 - 700

(RA)

No Data BMCL= 2.6 - 61

NOAEC = 12 - 6600 LOAEC = 14 - 700

(RA)

No Data BMCL= 2.6

NOAEC = 12 – 160LOAEC = 0.2 - 14

(RA)

Reproductive Toxicity3

NOAEL/LOAEL Oral (mg/kg/day)

Reproductive Toxicity

No Data NOAEL =100 (only dose

tested) Repro organ effects in some

repeated-dose studies (RA)

No Data NOAEL =100 (only dose tested)

Repro organ effects in some repeated-dose studies (RA)

No Data NOAEL =100 (only

dose tested) Repro organ effects in some repeated-

dose studies (RA)

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Table 9. Summary of Screening Information Data set Under the U.S. HPV Challenge Program –

Human Health Data1 Subcategory I4 Subcategory II5 Subcategory III6

Endpoints SPONSORED CHEMICAL

Pyrolysis gasoline

(Dripolene)a

(No CASRN)

SPONSOREDCHEMICALRecovered

oil from wastewater

(No CASRN)

SPONSORED CHEMICAL Pyrolysis C6

fraction

(No CASRN)

SPONSORED CHEMICAL

Pyrolysis C6 – C8 fraction

(No CASRN)

SPONSORED CHEMICAL

Pyrolysis C5 – C6 fraction

(No CASRN)

SPONSORED CHEMICAL

Hydro-treated C6

fraction (No CASRN)

SPONSORED CHEMICAL

Hydro-treated C6 – C7 fraction

(No CASRN)

SPONSORED CHEMICAL Aromatic

extract from benzene

extraction (64741-99-7)

SPONSORED CHEMICAL

Hydro-treated C6 – C8 fraction

(68410-97-9)

SPONSORED CHEMICAL Quench loop pyrolysis oil

(69013-21-4) Reproductive Toxicity3

NOAEC/LOAEC Inhalation (ppm/day)

Reproductive Toxicity

No Data No repro effects in repro

studies Inh (ppm)

NOAEC =500 - >2000 LOAEC = Not established

(RA)

No Data No repro effects in repro studies

NOAEC =500 - >2000 LOAEC = Not established

(RA)

No Data No repro effects in

repro studies NOAEC =

500 - >2000 LOAEC = Not

established (RA)

Developmental Toxicity3

NOAEL/LOAEL Oral (mg/kg-day)

Maternal Toxicity

Developmental Toxicity

No Data NOAEL = 20 – 1000 LOAEL = 50 – 100

NOAEL = 100 – 1000

LOAEL = Not established (RA)

No Data NOAEL = 20 – 1000

LOAEL = 100

NOAEL = 100 – 1000 LOAEL = Not established

(RA)

No Data NOAEL = 20

LOAEL = 50 – 100

NOAEL = 100 – 450

LOAEL = Not established

(RA) Developmental Toxicity3

NOAEC/LOAEC Inhalation (ppm/day)

Maternal Toxicity

Developmental Toxicity

No Data NOAEC = 10 – 1400 LOAEC = 50 - 7000

BMCL = 787

NOAEC = 10 – 600 LOAEC = 50 - 1000

(RA)

No Data NOAEC = 10 – 1400 LOAEC = 50 - 7000

BMCL = 787

NOAEC = 10 – 600 LOAEC = 50 - 1000

(RA)

No Data

NOAEC = 10 – 1000

LOAEC = 50 - 1000

NOAEC = 10 – 600

LOAEC = 50 - 1000

(RA)

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Table 9. Summary of Screening Information Data set Under the U.S. HPV Challenge Program –

Human Health Data1 Subcategory I4 Subcategory II5 Subcategory III6

Endpoints SPONSORED CHEMICAL

Pyrolysis gasoline

(Dripolene)a

(No CASRN)

SPONSOREDCHEMICALRecovered

oil from wastewater

(No CASRN)

SPONSORED CHEMICAL Pyrolysis C6

fraction

(No CASRN)

SPONSORED CHEMICAL

Pyrolysis C6 – C8 fraction

(No CASRN)

SPONSORED CHEMICAL

Pyrolysis C5 – C6 fraction

(No CASRN)

SPONSORED CHEMICAL

Hydro-treated C6

fraction (No CASRN)

SPONSORED CHEMICAL

Hydro-treated C6 – C7 fraction

(No CASRN)

SPONSORED CHEMICAL Aromatic

extract from benzene

extraction (64741-99-7)

SPONSORED CHEMICAL

Hydro-treated C6 – C8 fraction

(68410-97-9)

SPONSORED CHEMICAL Quench loop pyrolysis oil

(69013-21-4) Genetic Toxicity – Gene Mutation In vitro

No Data Positive

(RA)

No Data Positive

(RA)

Negative No Data Positive

(RA Genetic Toxicity – Chromosomal Aberrations In vitro

No Data Positive

(RA)

No Data Positive

(RA)

No Data Positive

(RA) Genetic Toxicity – Chromosomal Aberrations In vivo

No Data Positive

(RA)

No Data Positive

(RA)

Negative

No Data Positive

(RA) Genetic Toxicity- Unscheduled DNA Synthesis

Negative

Measured data in bold text; (RA) = Read Across; – indicates that endpoint was not evaluated for this substance ; BMDL or BMCL (lower limit of a one-sided 95% confidence interval for the benchmark dose [oral] or concentration [inhalation]). aAccording to the sponsor, Dripolene and pyrolysis gasoline are synonymous.

1 Please see Table 4 for general read-across strategy. 2 The range of values represents the individual values presented for the six components found in this stream as noted in Table 10. Note that the few mixtures data (although they are in other subcategories) fall within this range). 3 In general, the highest NOAEL/NOAEC, lowest LOAEL/LOAEC or lowest benchmark dose value from Table 10 are used for read-across. These values may come from different studies. 4 The range for all values (benchmark dose/concentration; NOAEL/NOAECs; and NOAEC/LOAECs) are presented since all 12 components are found in at least one stream in this subcategory. 5 The range for all values as noted in Footnote 4 except that it only considers 6/12 components (benzene, toluene, xylenes, styrene, naphthalene and Dicyclopentadiene) as noted in Table 4. 6 The range for all values as noted in Footnote 4 except naphthalene is not considered as noted in Table 4.

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Table 10 Summary of Screening Information Data set Under the U.S. HPV Challenge Program – Human Health Data1

SUPPORTING CHEMICALS Endpoints Isoprene3

(78-79-5)

n-Pentane4

(109-66-0)

1,3Cyclopenta-diene5

(542-92-7)

Isohexane6

(107-83-5)

Hexane7

(110-54-3)

Methylcyclo-pentane8

(96-37-7)

Benzene9

(71-43-2)

Toluene10

(108-88-3)

Xylenes, mixed11

(1330-20-7)

Styrene12

(100-42-5)

Naphtha-lene13

(91-20-3)

Dicyclo pentadiene14

(77-73-6) Acute Oral Toxicity LD50 (mg/kg)

2100

<1000

28,700

810-

10,000

5500-7500

3523-11,000

(rat) 2650

(mouse)

316

(rat) >2000

(mouse)

533 – 710

590

Acute Inhalation Toxicity Lc50 (ppm)

(rat) 64,500

(mouse) 56,363

98,662

14,426

48,000

13,700

(rat; mg/L)22.0 – 45.8

(mouse; mg/L)

19.9 – 27.9

(rat; mg/L) 18.8

(mouse; mg/L) 16.9

(mg/L) 9.5-11.8

>78

1000

Acute Dermal Toxicity LD50 (mg/kg)

12,400

(rat) >2500

(rabbit) >2000

Repeated-Dose Toxicity NOAEL/ LOAEL Oral (mg/kg-day)

(28-d, rat)

NOAEL = 500LOAEL =

2000

BMDL =

238

NOAEL =

250 LOAEL =

500

NOAEL

=200 LOAEL =

400

NOAEL =Not

established LOAEL = 50

NOAEL =4

LOAEL = 20

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Table 10 Summary of Screening Information Data set Under the U.S. HPV Challenge Program – Human Health Data1

SUPPORTING CHEMICALS Endpoints Isoprene3

(78-79-5)

n-Pentane4

(109-66-0)

1,3Cyclopenta-diene5

(542-92-7)

Isohexane6

(107-83-5)

Hexane7

(110-54-3)

Methylcyclo-pentane8

(96-37-7)

Benzene9

(71-43-2)

Toluene10

(108-88-3)

Xylenes, mixed11

(1330-20-7)

Styrene12

(100-42-5)

Naphtha-lene13

(91-20-3)

Dicyclo pentadiene14

(77-73-6) Repeated-Dose Toxicity NOAEC/ LOAEC Inhalation (ppm/day)

NOAEC = 220 LOAEC = 700

(rat; mg/L) NOAEC=20

(highest concentration

tested)

NOAEC =250 LOAEC = 500

BMCL = 61

BMCL = 2.6

(rat; mg/L) NOAEC =

0.10 LOAEC =

0.96

(rat; mg/L)NOAEC ~

2.4 LOAEC ~

4.7

(mouse; mg/L)

NOAEC ~ 2.4

LOAEC ~ 0.38

(6-month ; mg/L)

NOAEC ~ 1.5

LOAEC ~ 4.0

(4-week; mg/L)

NOAEC ~ 1.3

LOAEC > 1.3

MRL = 0.2

(2-y, rat; mg/L)

NOAEC(f) ~ 0.05

LOAEC(f) ~ 0.15

NOAEC (m)

~ Not established

LOAEC (m) ~ 0.05

Reproductive Toxicity NOAEL/ LOAEL Oral (mg/kg/day)

Reproductive Toxicity

Caused testicular

damage and changes in

estrus cyclicity in mice in 13-

week inhalation

study.

No effects on

reproductive organs in rats in 90-

day repeated-

dose study

– – Causes testicular damage in animals at high oral (>4000

mg/kg/day)

– – – – No testicular effects in 90-day study in

rats

No effects in reproductive

organs in subchronic or

chronic studies (oral

and inhalation).

NOAEL =100 (highest dose

tested)

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Table 10 Summary of Screening Information Data set Under the U.S. HPV Challenge Program – Human Health Data1

SUPPORTING CHEMICALS Endpoints Isoprene3

(78-79-5)

n-Pentane4

(109-66-0)

1,3Cyclopenta-diene5

(542-92-7)

Isohexane6

(107-83-5)

Hexane7

(110-54-3)

Methylcyclo-pentane8

(96-37-7)

Benzene9

(71-43-2)

Toluene10

(108-88-3)

Xylenes, mixed11

(1330-20-7)

Styrene12

(100-42-5)

Naphtha-lene13

(91-20-3)

Dicyclo pentadiene14

(77-73-6) Reproductive Toxicity NOAEC/ LOAEC Inhalation (mg/L/day)

Reproductive Toxicity

Effects on male and female

reproductive organs

observed at 0.96 mg/L in 13-week inhalation repeated-

dose toxicity study in

mice.

NOAEC =

2.3 LOAEC =

7.5

NOAEC =

2.2 (highest

concentration tested)

NOAEC =

2.1 (highest

concentration tested)

Developmental Toxicity

NOAEL/ LOAEL Oral (mg/kg-day)

Maternal Toxicity

Developmental Toxicity

NOAEL = 1000

(highest dose tested)

NOAEL =

1000 (highest dose

tested)

– –

– –

– –

– –

– –

– –

NOAEL = Not established

LOAEL = 50

NOAEL > 450LOAEL = Not

established

NOAEL =20 LOAEL = 100

NOAEL =100 (highest dose

tested)

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Table 10 Summary of Screening Information Data set Under the U.S. HPV Challenge Program – Human Health Data1

SUPPORTING CHEMICALS Endpoints Isoprene3

(78-79-5)

n-Pentane4

(109-66-0)

1,3Cyclopenta-diene5

(542-92-7)

Isohexane6

(107-83-5)

Hexane7

(110-54-3)

Methylcyclo-pentane8

(96-37-7)

Benzene9

(71-43-2)

Toluene10

(108-88-3)

Xylenes, mixed11

(1330-20-7)

Styrene12

(100-42-5)

Naphtha-lene13

(91-20-3)

Dicyclo pentadiene14

(77-73-6) Developmental Toxicity

NOAEC/ LOAEC Inhalation (ppm/day)

Maternal Toxicity

Developmental Toxicity

Maternal Toxicity

Developmental Toxicity

(mouse) NOAEC = 1400 LOAEC = 7000

NOAEC = Not

established LOAEC = 280

(rat) NOAEC = 7000

(highest concentration

tested)

NOAEC = 7000 (highest

concentration tested)

NOAEC = 1000

LOAEC = 5000

BMCL = 787

(rat; mg/L) NOAEC =

0.96 (highest

concentration tested)

NOAEC = 0.096

LOAEC = 0.96

(mouse; mg/L)

NOAEC = 0.064

(highest concentration tested)

NOAEC =

0.032 LOAEC =

0.064

(mg/L) NOAEC = 7.5

(highest concentration

tested)

NOAEC = 2.3LOAEC

= 3.8

(mg/L) NOAEC

= 2.2 LOAEC

= 4.4

NOAEC = 0.44

LOAEC = 2.2

(mg/L) NOAEC = 0.2

LOAEC = 0.64

NOAEC = 0.2 LOAEC =

0.64

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Table 10 Summary of Screening Information Data set Under the U.S. HPV Challenge Program – Human Health Data1

SUPPORTING CHEMICALS Endpoints Isoprene3

(78-79-5)

n-Pentane4

(109-66-0)

1,3Cyclopenta-diene5

(542-92-7)

Isohexane6

(107-83-5)

Hexane7

(110-54-3)

Methylcyclo-pentane8

(96-37-7)

Benzene9

(71-43-2)

Toluene10

(108-88-3)

Xylenes, mixed11

(1330-20-7)

Styrene12

(100-42-5)

Naphtha-lene13

(91-20-3)

Dicyclo pentadiene14

(77-73-6) Genetic Toxicity – Gene Mutation In vitro

Negative Negative – – Negative – Positive Negative Negative Negative Negative Negative

Genetic Toxicity – Chromosomal Aberrations In vitro

Negative Equivocal – – Negative – Positive Negative Negative Positive

Positive Negative

Genetic Toxicity – Chromosomal Aberrations In vivo

Positive Negative – – Positive

– Positive Negative Negative Negative Negative -

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Table 10 Summary of Screening Information Data set Under the U.S. HPV Challenge Program – Human Health Data1

SUPPORTING CHEMICALS Endpoints Isoprene3

(78-79-5)

n-Pentane4

(109-66-0)

1,3Cyclopenta-diene5

(542-92-7)

Isohexane6

(107-83-5)

Hexane7

(110-54-3)

Methylcyclo-pentane8

(96-37-7)

Benzene9

(71-43-2)

Toluene10

(108-88-3)

Xylenes, mixed11

(1330-20-7)

Styrene12

(100-42-5)

Naphtha-lene13

(91-20-3)

Dicyclo pentadiene14

(77-73-6) Additional Information Skin Irritation Eye Irritation Skin Sensitization Carcinogenicity Neurotoxicity

– – –

Positive –

Not Irritant Minimal Negative

– –

– – – – –

– – –

– –

– – – –

Positive

– – – – –

– – –

Positive –

Irritating Irritating Negative

Negative Positive

Irritating Irritating

-

Negative Positive

Irritating Irritating Negative

Positive Positive

Slightly irritating

Not irritatingNegative

Positive

Moderately Irritating

Moderately Irritating

– – –

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Table 10 Summary of Screening Information Data set Under the U.S. HPV Challenge Program – Human Health Data1

SUPPORTING CHEMICALS Endpoints Isoprene3

(78-79-5)

n-Pentane4

(109-66-0)

1,3Cyclopenta-diene5

(542-92-7)

Isohexane6

(107-83-5)

Hexane7

(110-54-3)

Methylcyclo-pentane8

(96-37-7)

Benzene9

(71-43-2)

Toluene10

(108-88-3)

Xylenes, mixed11

(1330-20-7)

Styrene12

(100-42-5)

Naphtha-lene13

(91-20-3)

Dicyclo pentadiene14

(77-73-6) Measured data in bold text; (RA) = Read Across; – indicates that endpoint was not evaluated for this substance ; (m) = male; (f) = female; BMDL or BMCL (lower limit of a one-sided 95% confidence interval for the benchmark dose [oral] or concentration [inhalation]); MRL = ATSDR Minimal Risk Level 1 Data were taken from documents found at the URLs listed in Table 4. If there were no readily available and reliable data, information was taken from Appendix 3 of the Category Summary submitted by the sponsor. Many of these chemicals are well-studied and so it is difficult to find a representative NOAEL/LOAEL for read-across purposes (especially for repeated-dose or systemic toxicity). For this HC, the study chosen for developing a hazard value for eventual risk assessment was used and is presented here (i.e., MRL from ATSDR, RfD from IRIS, key study from EU risk assessments, etc.) for the repeated-dose endpoint. Dose/derived Benchmark Dose (BMD) values were used; NOT the derived value with the associated safety/uncertainty factors. In those cases where a BMD was used, LOAEL/LOAECs are not presented and the BMD used was the BMDL (lower limit of a one-sided 95% confidence interval for the BMD). Also, many chemicals caused local effects (e.g., naphthalene, styrene), but these were not considered here – only systemic effects were used. Finally, although many human studies were referenced and summarized in the review documents examined, none were used here for read-across purposes unless they were the study chosen for MRL/RfD/key study use in their respective review documents.. 2 All inhalation data are presented in parts per million (ppm) for ease in use in read-across for complex mixtures. 3Isoprene. The studies reported here were taken from the SIDS Initial Assessment Profile (SIAP) from the 2005 OECD SIDS document published by UNEP. Studies were reported in both rats and mice; however, mice were more sensitive than rats in all cases and all values reported here are from studies in mice. The repeated dose study was a 13 week inhalation study in mice which showed hematology effects at the LOAEC. In the developmental study, maternal and developmental effects observed at the LOAEC were reductions in maternal weight gain and uterine weight and reductions in fetal body weight, respectively. All genotoxicity data were negative and the NTP cancer studies were positive (i.e., malignant tumors at various sites) in mice but negative (some benign tumors) in rats. 4n-Pentane. All values were taken from the European Union (EU) risk assessment published in 2003. There were no effects observed at the highest concentrations tested in the repeated-dose and developmental studies and available genotoxicity studies were also negative. 5 1,3-Cyclopentadiene. Information taken from Appendix 3 of the submitted Category Summary. 6 Isohexane – there was no readily available information from sources searched on isohexane. The data provided in Appendix 3 of the submission is for a different chemical (misidentified as 3-methylpentane – isohexane is 2-methylpentane). 7n-Hexane. IRIS derived two benchmark concentration (BMC) values; one for decreases in motor conduction value in rats (BMCL = 122 ppm; adjusted to Human Equivalent Concentration of 215 mg/m3, converted to 61 ppm) and one for fetal malformations in a developmental toxicity study (BMCL = 943 ppm, adjusted to Human Equivalent Concentration of 2770 mg/m3, converted to 787 ppm). Both values were derived from inhalation studies. For the neurological studies, two different studies were used (Ono et al, 1982 and Huang et al., 1989), although the BMC was chosen from the Huang et al. study (rats were exposed for up to 16 weeks at concentrations of 0, 500, 1200 or 3000 ppm). In the developmental study (Mast et al., 1987) pregnant rats were exposed to concentrations of 0, 200, 1000 and 5000 ppm; maternal toxicity was see at 5000 ppm as decreases in body weight. 8 Methylcyclopentane. Information taken from Appendix 3 of the submitted Category Summary; 28-day study in rats with no effects at 500 mg/kg/d and kidney effects and mortality at 2000 mg/kg/d. 9Benzene. The acute inhalation value was taken from ATSDR 2007. The 2002 IRIS document was used to identify the repeated-dose toxicity data to be used in this HC. The key study was the human epidemiology study (Rothman et al., 1996a as cited in IRIS). Three exposure groups were identified (0, 13.6 ppm and 91.9 ppm) in this occupational exposure study in China and the effect of concern was absolute lymphocyte count (ALC) – which represents blood effects. The calculated BMCL = 7.2 ppm. Because human data were used, there is no need to perform a human equivalent concentration; however, the data are from the occupational setting so it was adjusted to account for 24 hours of exposure vs the eight hours observed in the work environment (starting with 8.2 mg/m3 [dosimetrically correct valuea] and converting to ppm = 2.6 ppm). Reproductive toxicity data taken from Ward et al., (1985 (Table 7 in IRIS, 2002). Developmental data taken from Kuna and Kapp (1981) – Table 8 in IRIS, 2002 (maternal effects were reductions in body weigh/body weight gain and developmental effects were decreased pup body weight and skeletal and brain abnormalities). Most of the genotoxicity data reviewed in both ATSDR and IRIS point to benzene metabolites being responsible for (primarily) chromosomal effects).

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Table 10 Summary of Screening Information Data set Under the U.S. HPV Challenge Program – Human Health Data1

SUPPORTING CHEMICALS Endpoints Isoprene3

(78-79-5)

n-Pentane4

(109-66-0)

1,3Cyclopenta-diene5

(542-92-7)

Isohexane6

(107-83-5)

Hexane7

(110-54-3)

Methylcyclo-pentane8

(96-37-7)

Benzene9

(71-43-2)

Toluene10

(108-88-3)

Xylenes, mixed11

(1330-20-7)

Styrene12

(100-42-5)

Naphtha-lene13

(91-20-3)

Dicyclo pentadiene14

(77-73-6) 10Toluene. The 2005 IRIS document was used to obtain data on toluene; with the exception of the acute inhalation data which came from Appendix 3 of the submitted Category Summary. The oral repeated dose BMDL of 238 mg/kg/day was derived from a 90-day NTP repeated dose assay and is based on kidney effects. The inhalation repeated-dose value was based on a combining of 10 human studies with the critical effect being a deficit in neurological function. A benchmark dose analysis was not performed; rather an average NOAEL of 46 mg/m3 (12 ppm) was derived – after adjusting the human exposures from occupational (i.e., 8 hours) to continuous (24 hours). Although an average LOAEL was not presented; the lowest LOAEL was reported to be 40 ppm (adjusted to 24 hours = 14 ppm). Reproductive data taken from API (1984) and Roberts (2003) as cited in IRIS document. Rats were exposed to toluene via whole-body inhalation exposure at levels of 0, 100, 500 and 2000 ppm; there were no effects on fertility. Developmental data taken from Thiel and Chaloud (1997) as cited in IRIS document. Pregnant rats were exposed via inhalation to toluene at levels of 0, 300, 600, 1000 and 1200 ppm on days 9-21 of gestation. The LOAEC for maternal and developmental toxicity was 1000 ppm and based on reduced maternal weigh and reduced pup weight. The IRIS document states that “….toluene has generally not been genotoxic in short-term testing”. Toluene was negative in both rats and mice in NTP cancer bioassays. 11Xylenes. The 2007 ATSDR document for xylenes was used. This document addresses the three isomers (ortho, meta and para) as well as mixed xylenes (which contains all three isomers plus ethylbenzene). The chronic oral MRL is based on the 1986 NTP cancer bioassay in which rats were exposed to 0, 250 or 500 mg/kg/d of mixed xylenes via gavage for 103 weeks. Effects (mortality and reduced body weights) were seen only in the high dose group. The chronic inhalation MRL was based on an occupational study in humans (Uchida et al., 1993) in which there were only a control group and an exposed group. The exposed group experienced neurotoxic symptoms (subjective, self-reported – “…increased prevalence of anxiety, forgetfulness, inability to concentrate, eye and nasal irritation, dizziness, and sore throats”) and exposures were confirmed by measuring xylene metabolites in urine and estimated to be a geometric mean of 14 ppm over seven years. The reproductive toxicity study is from Biodynamics (1983) and includes inhalation exposure to rats during premating, mating, gestation and lactation; but only one concentration was used (500 ppm). There were no effects on fertility. Developmental studies have been performed in rats with each xylene isomer and with mixed xylenes as well. Most studies show developmental effects (reduced pup weight, fetotoxicity), some show neurobehavioral effects (reductions in water maze performance), and some show maternal effects. The lowest LOAECs for maternal (decreased body weight) and developmental (decreased fetal weight) are presented here (as taken from Table 3-1 in the ATSDR profile). ATSDR considers the xylenes to not be genotoxic. The NTP cancer bioassay reported above was negative. 12Styrene. The 2007 ATSDR document for styrene was used. The chronic inhalation MRL was based on a meta analaysis of multiple occupational studies in humans (Beningnus, 2005). The effects of concern were biologically significant decreases in choice reaction time and color vision impairment. The calculated LOAEC was 20 ppm. A two-generation reproductive toxicity (Cruzan et al.,2005b) was reported to have no effects on reproduction, estrus cycle, or sperm effects at inhalation exposure up to500 ppm – no other specifics were provided. Developmental studies have been performed in rats, mice, hamsters and rabbits. There did not appear to be maternal effects in any of these studies. The lowest LOAEC for developmental toxicity was 300 ppm for increased mortality and developmental delays in righting reflex and incisor eruption in hamsters (as taken from Table 3-1 in the ATSDR profile). ATSDR considers the genotoxicity of styrene to be inconsistent. In vitro gene mutations in bacteria are negative without metabolic activation and equivocal with activation. Chromosomal effects have been reported in human lymphocytes in the absence of activation. ATSDR considers the positive inhalation cancer studies in mice of possible significance to humans. 13Naphthalene. The 2005 ATSDR document for naphthalene was used. The intermediate oral ATSDR MRL was based on transient clinical signs in pregnant rats in a developmental study. Doses were 50, 150 and 200 mg/kg/d (oral) during gestation and clinical signs were observed at the lowest dose (NTP, 1991a as cited in ATSDR, 2005). The available chronic oral MRL was based on either 1- or 2-methylnaphthalene and so were not considered here. The chronic inhalation ATSDR MRL for naphthalene is also reported here, but it is based on local effects since the effects noted in the cancer study did not include systemic effects at any dose level (using combined data from NTP 1992a, 2000 and Abdo et al., 2001; in which rats were exposed to 0, 10, 30 or 60 ppm naphthalene and mice were exposed to 0, 10 or 30 ppm). In both studies, neoplastic and non-neoplastic effects were restricted to the nose and lung and were used to derive a human adjusted LOAEC of 0.2 ppm (rat data). Available in vitro data show naphthalene to not be genotoxic. 14 Dicyclopentadiene. The studies reported here were taken from body of the SIDS Initial Assessment Report (SIAR) from the 1998 OECD SIDS document published by UNEP. A combined repeated-dose/reproductive/developmental toxicity study was performed in rats via oral gavage at doses of 0, 4, 20 and 100 mg/kg/d. Systemic effects at 20 mg/kg/d included kidney and adrenal gland effects in males. Maternal effects at the high dose of 100 mg/kg/d included mortality and inability to nurse pups. Finally, there were no effects on reproductive parameters. In vitro genotoxicity tests were negative.

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Conclusion: For the human health endpoints, the ten streams in the high benzene naphthas category have been divided into three subcategories based on similarities and differences in the individual stream components. This division of the streams was based on the existence and concentration of 12 key components in each stream and is explained more fully in the Category Justification and Justification for Supporting Chemical sections of this document where the use of read-across is also described (see Table 4). Subcategory I: Pygas The acute oral and dermal toxicity of pyrolysis gasoline (No CASRN) is low in rats and rabbits, respectively. All other human health endpoints are filled using supporting chemical (stream component) data. Available information on repeated-dose toxicity for the supporting chemicals reveals a variety of effects from both inhalation and oral exposures. The range in benchmark dose/concentration (BMDL or BMCL) and NOAECs are from 2.6 – 61 ppm and 12 - 6600 ppm/day for inhalation and from a single BMDL of 238 mg/kg/day and NOAELs of from 4-500 mg/kg/day for oral exposures. The inhalation BMCL is based on blood effects in a human epidemiology study with CASRN 71-43-2 in China; and the 61 ppm value is based on decreases in motor conduction velocity measurements in animals for CASRN 110-54-3. The low NOAEC is based on deficits in neurological function based on a meta-analysis of 10 human occupational studies for CASRN 108-88-3 (average exposures where effects were observed was estimated to be 14 ppm). The high NOAEC value is based on no effects seen at this highest dose in a repeated-dose study with CASRN 109-66-0. However, there is a LOAEC lower than the lowest NOAEC or BMCL value; the ATSDR MRL (minimum risk level) for CASRN 91-20-3 estimated a LOAEC of 0.2 ppm for humans based on non-neoplastic and neoplastic effects in rats (restricted to the nose and lungs) in a two-year cancer study in which the lowest concentration used was 10 ppm. The oral BMDL is based on kidney effects in a 90-day animal study with CASRN 108-88-3. The low end of the range of oral NOAEL values is based on systemic effects observed in a combined repeated-dose/reproductive/developmental test with CASRN 77-73-6 in which rats experienced kidney and adrenal gland effects at 20 mg/kg/day. At the high end, kidney effects and mortality were observed at 2000 mg/kg/day in a 28-day study with CASRN 96-37-7. No effects on the reproductive organs were observed in oral repeated-dose studies in rats with CASRNs 109-66-0, 100-42-5 and 91-20-3; however, CASRN 78-79-5 showed testicular effects and changes in estrus cyclicity after repeated oral dosing in mice. CASRN 110-54-3 caused testicular damage in animals at high (>4000 mg/kg/day) oral doses. In a combined oral repeated-dose/reproductive/developmental toxicity screening test in rats with CASRN 77-73-6, no adverse effects on reproductive parameters were observed; the NOAEL for reproductive toxicity is 100 mg/kg/day (highest dose tested). Repeated inhalation exposures in mice with CASRN 71-43-2 showed effects on the reproductive organs in both sexes. In an inhalation reproductive toxicity screening test and a two-generation reproductive toxicity study in rats, CASRN 108-88-3 significantly decreased the sperm count, epididymal weight and pup weights at 7.5 mg/L/day; the NOAEC for reproductive toxicity is 2.3 mg/L/day. In inhalation reproductive toxicity studies in rats, CASRNs 1330-20-7 (one-generation study) and 100-42-5 (two-generation study) showed no treatment-related effects on reproductive parameters; the NOAEC for reproductive toxicity is 2 mg/L/day (highest concentration tested).

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For developmental toxicity, a BMCL of 787 ppm was determined for CASRN 110-54-3 (based on fetal malformations in the developmental toxicity study). In a prenatal oral developmental toxicity study in rats, CASRN 109-66-0 showed no maternal or developmental effects; the NOAEL for maternal developmental toxicity is 1000 mg/kg-day (highest dose tested). In the combined oral repeated-dose/reproductive/developmental toxicity screening test in rats with CASRN 77-73-6, no abnormal findings attributed to the test substance were found for external features, clinical signs or on necropsy of offspring; the NOAEL for maternal toxicity is 20 mg/kg-day (reduced body weight at 100 mg/kg-day) and for developmental toxicity is 100 mg/kg-day (highest dose tested). In prenatal inhalation developmental toxicity studies in rats and mice, CASRN 7879-5 did not produce any maternal or developmental toxicity in rats following exposure to concentrations as high as 19.5 mg/L/day; the NOAEC for maternal/developmental toxicity is 19.5 mg/L/day. In mice, maternal weight gain and uterine weight were significantly reduced at 19.5 mg/L/day. Significant reductions in fetal bodyweight were observed at 1 mg/L/day in female fetuses (lowest concentration tested); the NOAEC for maternal toxicity is 3.9 mg/L/day and the NOAEC is not established for developmental toxicity. In the two-generation inhalation reproductive toxicity study in rats with CASRN 108-88-3, developmental toxicity included decreased fetal growth and pup weight accompanied by delayed ossification in F1 and F2 offspring at 3.8 mg/L/day; the NOAEC for developmental toxicity is 2.3 mg/L/day and the NOAEC for maternal toxicity is 4.3 mg/L/day (highest concentration tested). In the two-generation inhalation reproductive toxicity study in rats, CASRN 100-42-5 showed decreased body weights and decreased fetal body weights and delayed development at 0.64 mg/L/day; the NOAEC for maternal and developmental toxicity is 0.2 mg/L/day. In a prenatal inhalation developmental toxicity study in rats, CASRN 1330-20-7 decreased body weight, weight gain and food consumption in dams at 4.4 mg/L/day and decreased fetal body weight at 2.2 mg/L/day; the NOAEC for maternal toxicity is 2.0 mg/L/day and the NOAEC for developmental toxicity is 0.44 mg/L/day. In an inhalation prenatal developmental toxicity study in mice, CASRN 71-43-2 showed effects on the hematopoietic system in offspring at 0.064 mg/L/day; the NOAECs for maternal and developmental toxicity are 0.064 mg/L/day (highest concentration tested) and 0.032 mg/L/day, respectively. Of the tested supporting chemicals, only CASRN 71-43-2 was mutagenic in bacteria and mammalian cells in vitro. CASRNs 78-79-5, 110-54-3, 108-88-3, 1330-20-7 and 77-73-6 did not induce chromosomal aberrations in vitro; CASRN 109-66-0 showed equivocal results and CASRNs 71-43-2, 100-42-5 and 91-20-3 were positive. CASRNs 109-66-0, 108-88-3, 1330-20-7, 100-42-5 and 91-20-3 did not induce chromosomal aberrations in vivo; CASRNs 78-79-5, 110-54-3 and 71-43-2 were positive. Some of the supporting chemicals increased the incidence of tumors (CASRNs 78-79-5, 71-43-2, 100-42-5 and 91-20-3) while CASRNs 108-88-3 and 1330-20-7 did not. The supporting chemicals are generally irritating to the skin and eyes but are not skin sensitizers. CASRNs 110-54-3, 108-88-3, 1330-20-7 and 100-42-5 are neurotoxic. Subcategory II: High Benzene Naphthas The supporting chemical data from subcategory I (excepting data for CASRN 91-20-3) can also be used to address the human health endpoints for subcategory II. Please see summary of available data in subcategory I above.

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The acute oral and inhalation toxicity of CASRN 68410-97-9 in rats is low. CASRN 68410-97-9 was not mutagenic in bacteria in vitro and did not induce mouse micronuclei in vivo. CASRN 68410-97-9 did not induce unscheduled DNA synthesis. Subcategory III: Quench/Compressor Oil There are no human health data available on the sponsored stream. The human health hazard of subcategory III is characterized by data for CASRNs 71-43-2, 108-88-3, 1330-20-7, 100-42-5, 77-73-6 and 91-20-3. Please see summary of available data for these CASRNS in subcategory I above. 4. Hazard to the Environment A summary of aquatic toxicity data submitted for SIDS endpoints is provided in Table 11. The table also indicates where data for tested category members are read-across (RA) to untested members of the category. Acute Toxicity to Fish Benzene (CASRN 71-43-2, supporting chemical) (1) http://webnet.oecd.org/hpv/UI/handler.axd?id=b09084f6-37fd-4969-b474-cbe687e5f2ba 96-h LC50 = 5.3 mg/L (2) Rainbow trout (Oncorhynchus mykiss) juveniles were exposed to CASRN 71-43-2 for 96 hours under flow-through conditions. 96-h LC50 = 9.9 mg/L (Hodson et al. 1984). (3) Fathead minnow (Pimephales promelas) fry were exposed to CASRN 71-43-2 for 96 hours under flow through conditions. 96-h LC50 = 15.6 mg/L (Marchini et al. 1992). n-Pentane (CASRN 109-66-0, supporting chemical) http://webnet.oecd.org/hpv/UI/handler.axd?id=940b1ed1-84c8-4433-98e9-18b19fc8f99e 96-h LC50 = 4.26 mg/L Naphthalene (CASRN 91-20-3, supporting chemical) (1) http://webnet.oecd.org/hpv/UI/handler.axd?id=663663d9-02b2-4469-8df2-d98919ac0aa9 96-h LC50 = 1- 10 mg/L (2) Rainbow trout (Oncorhynchus mykiss) juveniles were exposed to CASRN 91-20-3 for 96 hours. Temperature = 15 °C, pH = 7.9 – 8.0, hardness = 535-596 mg/L CaCO3, alkalinity = 147 – 165 mg/L CaCO3, conductivity = 901 – 1051 µmhos/cm, and DO = 7.0 mg/L. 96-h LC50 = 1.6 mg/L (DeGraeve et al. 1982). (3) Fathead minnow (Pimephales promelas) fry (120 days post hatch) were exposed to CASRN 91-20-3 for 96 hours at the following concentrations: 0.73, 1.95, 4.29, 10.71, and 24.74 mg/L. 96-h LC50 = 9.9 mg/L (Biodynamics, Inc. 1987).

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Toluene (CASRN 108-88-3, supporting chemical) (1) http://webnet.oecd.org/hpv/UI/handler.axd?id=78848f77-7cae-4745-a30e-8eb6ec7a4df7 96-h LC50 = 5.4-26 mg/L (2) Rainbow trout (Oncorhynchus mykiss) juveniles were exposed to CASRN 108-88-3 for 96 hours. Temperature = 13.9 - 14.3 °C, pH = 6.9 - 6.99, hardness = 54.5 - 56.1 mg/L CaCO3, alkalinity = 42.1 - 42.7 mg/L CaCO3, conductivity = 87.2 - 96.6 umhos/cm, and DO = 64.8 - 75.2 % saturation. 96-h LC50 = 6.78 mg/L (Brooke et al. 1986). m-Xylene (CASRN 108-38-3, supporting chemical) (1) Rainbow trout (Oncorhynchus mykiss) were exposed to CASRN 108-38-3 for 96 hours. http://webnet.oecd.org/hpv/UI/handler.axd?id=7f6b4807-5217-4626-b47c-e139327a412b. 96-h LC50 = 2.6 mg/L (2) Fathead minnow (Pimephales promelas) were exposed to CASRN 108-38-3 for 96 hours. http://webnet.oecd.org/hpv/UI/handler.axd?id=7f6b4807-5217-4626-b47c-e139327a412b 96-h LC50 = 26.7 mg/L Acute Toxicity to Aquatic Invertebrates Benzene (CASRN 71-43-2, supporting chemical) (1) http://webnet.oecd.org/hpv/UI/handler.axd?id=b09084f6-37fd-4969-b474-cbe687e5f2ba 48-h EC50 = 10 mg/L (2) Ceriodaphnia dubia were exposed to CASRN 71-43-2 for 48 hours in a closed system. 48-h EC50 = 17.2 mg/L (Niederlehner et al. 1998). n-Pentane (CASRN 109-66-0, supporting chemical) http://webnet.oecd.org/hpv/UI/handler.axd?id=940b1ed1-84c8-4433-98e9-18b19fc8f99e 48-h EC50 = 2.7 mg/L Naphthalene (CASRN 91-20-3, supporting chemical) (1) http://webnet.oecd.org/hpv/UI/handler.axd?id=663663d9-02b2-4469-8df2-d98919ac0aa9 48-h EC50 = 1- 10 mg/L (2) (1)http://webnet.oecd.org/hpv/UI/handler.axd?id=663663d9-02b2-4469-8df2-d98919ac0aa9. 48-h NOEC = 0.22 – 0.6 mg/L (3) Daphnia magna were exposed to CASRN 91-20-3 for 48 hours under flow through conditions. D. magna were exposed to a control, 0.25, 0.27, 1.96, and 5.15 mg/L of 100% purity. The water quality values were acceptable and measured values were reported. 96-h EC50 = 1.96 mg/L (Bio Dynamics Inc. 1987). Toluene (CASRN 108-88-3, supporting chemical) Daphnia magna were exposed to CASRN 108-88-3 for 48 hours. http://webnet.oecd.org/hpv/UI/handler.axd?id=78848f77-7cae-4745-a30e-8eb6ec7a4df7

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48-h EC50 = 11.5 mg/L m-Xylene (CASRN 108-38-3, supporting chemical) Daphnia magna were exposed to CASRN 108-88-3 for 48hours. http://webnet.oecd.org/hpv/UI/handler.axd?id=7f6b4807-5217-4626-b47c-e139327a412b 48-h EC50 = 8.5 mg/L Toxicity to Aquatic Plants Benzene (CASRN 71-43-2, supporting chemical) (1) http://webnet.oecd.org/hpv/UI/handler.axd?id=b09084f6-37fd-4969-b474-cbe687e5f2ba 72-h EC50 (biomass) = 28 mg/ L (Galassi et al. 1988). (2) Green algae (Pseudokirchneriella subcapitata) were exposed to CASRN 71-43-2 for 72 hours. 72-h EC50 = 29 mg/ L (Galassi et al. 1988). n-Pentane (CASRN 109-66-0, supporting chemical) http://webnet.oecd.org/hpv/UI/handler.axd?id=940b1ed1-84c8-4433-98e9-18b19fc8f99e 96-h EC50 (growth rate) = 10.7 mg/L Naphthalene (CASRN 91-20-3, supporting chemical) http://webnet.oecd.org/hpv/UI/handler.axd?id=663663d9-02b2-4469-8df2-d98919ac0aa9 72-h EC50 (growth rate) = 0.4 mg/L Toluene (CASRN 108-88-3, supporting chemical) Green algae (Pseudokirchneriella subcapitata) were exposed to CASRN 108-38-3 for 72 hours. 72-h EC50 = 12.5 mg/ L (Galassi et al. 1988). m-Xylene (CASRN 108-38-3, supporting chemical) (1) Green algae (Pseudokirchneriella subcapitata) were exposed to CASRN 108-38-3 for 72 hours. http://webnet.oecd.org/hpv/UI/handler.axd?id=7f6b4807-5217-4626-b47c-e139327a412b 72-h EC50 = 3.2 mg/L (Herman et al. 1990). (2) Green algae (Pseudokirchneriella subcapitata) were exposed to CASRN 108-38-3 for 72 hours. 72-h EC50 = 4.9 mg/ L (Galassi et al. 1988). Conclusion: No data are available for the sponsored streams. The 96-h LC50 value for fish ranges from 1 – 10 mg/L for CASRN 91-20-3, 5.4 – 26 mg/L for CASRN 108-88-3, 2.6 – 26.7 mg/L for CASRN 108-38-3, 5.3 – 15.6 mg/L for CASRN 71-43-2 and is 4.3 mg/L for CASRN 109-66-0. The 48-h EC50 value for aquatic invertebrates ranges from 0.22 – 1.96 mg/L for CASRN 91-20-3, 10 – 17.2 mg/L for CASRN 71-43-2, is 8.5 mg/L for CASRN 108-88-3, 11.5 mg/L for CASRN 108-38-3 and 2.7 mg/L for CASRN 109-66-0. The 72-h EC50 value for toxicity to aquatic plants is 0.4 mg/L for CASRN 91-20-3, 12.5 mg/L for CASRN 108-88-3, 10.7 mg/L for CASRN 109-66-0, 28 mg/L for CASRN 71-43-2 and ranges from

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3.2 – 4.9 mg/L for CASRN 108-38-3. 5. References

Brooke, L.T., D.J. Call, S.H. Poirier, and S.L. Harting. 1986. Toxicity of Toluene to Several Freshwater Species. Center for Lake Superior Environmental Stud., Univ.of Wisconsin-Superior, Superior, WI (Report to Battelle Memorial Research Institute, Columbus, OH) :10 p. Biodynamics, Inc. 1987. A Flow-Through Acute Fish Toxicity Test of Naphthalene. EPA/OTS Doc.#86-870000910 :26 p. (NTIS/OTS 0515348). DeGraeve, G.M., Elder, R.G., Woods, D.C. and Bergman, H.L. 1982. Effects of Naphthalene and Benzene on Fathead minnows and Rainbow trout. Archives of Environmental Contamination and Toxicology 11(4): 487-490. Devlin, E.W., J.D. Brammer, and R.L. Puyear. 1982. Acute Toxicity of Toluene to Three Age Groups of Fathead Minnows (Pimephales promelas). Bulletin of Environmental Contamination and Toxicology. 29(1):12-17. Galassi, S., Mingazzini, M., Vigano, L., Cesareo, D., and Tosato, M.L. 1988. Approaches to Modeling Toxic Responses of Aquatic Organisms to Aromatic Hydrocarbons. Ecotoxicology and Environmental Safety. 16(2):158-169. Herman, D.C., Inniss, W.E., and Mayfield, C.I. 1990. Impact of Volatile Aromatic Hydrocarbons, Alone and in Combination, on Growth of the Freshwater Alga Selenastrum capricornutum. Aquatic Toxicology. 18(2):87-100. Niederlehner, B.R., Cairns, J. Jr., and Smith, E.P.1998. Modeling Acute and Chronic Toxicity of Nonpolar Narcotic Chemicals and Mixtures to Ceriodaphnia dubia. Ecotoxicology and Environmental Safety. 39:136-146.

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Table 11. Summary of the Screening Information Data Set as Submitted under the U.S. HPV Challenge Program –

Aquatic Toxicity Data

Endpoints SPONSORED CHEMICAL

Pyrolysis gasoline

(No CASRN)

SPONSORED CHEMICAL

Pyrolysis C6 fraction

(No CASRN)

SPONSORED CHEMICAL

Pyrolysis C6-C8 fraction

(No CASRN)

SPONSORED CHEMICAL

Hydrotreated C6 fraction

(No CASRN)

SPONSORED CHEMICAL

Hydrotreated C6-C7 fraction

(No CASRN)

SPONSORED CHEMICAL

Hydrotreated C6-C8 fraction (68410-97-9)

SPONSORED CHEMICAL

Aromatic extract from benzene ext.

(64741-99-7) Fish 96-h LC50 (mg/L)

No Adequate Data 1-26.7 (RA)

No Adequate Data 1-26.7 (RA)

No Adequate Data 1-26.7 (RA)

No Adequate Data 1-26.7 (RA)

No Adequate Data 1-26.7 (RA)

No Adequate Data1-26.7 (RA)

No Adequate Data1-26.7 (RA)

Aquatic Invertebrates 48-h EC50 (mg/L)

No Adequate Data 1-17.2 (RA)

No Adequate Data 1-17.2 (RA)

No Adequate Data 1-17.2 (RA)

No Adequate Data 1-17.2 (RA)

No Adequate Data 1-17.2 (RA)

No Adequate Data1-17.2 (RA)

No Adequate Data1-17.2 (RA)

Aquatic Plants 72-h EC50 (mg/L)

No Adequate Data 0.4-29 (RA)

No Adequate Data 0.4-29 (RA)

No Adequate Data 0.4-29 (RA)

No Adequate Data 0.4-29 (RA)

No Adequate Data 0.4-29 (RA)

No Adequate Data0.4-29 (RA)

No Adequate Data0.4-29 (RA)

Endpoints SPONSORED CHEMICAL

Quench Loop/Compressor

Oil (69013-21-4)

SPONSORED CHEMICAL

Recovered oil from wastewater

(68956-70-7)

SUPPORTING CHEMICAL

n-Pentane

(109-66-0)

SUPPORTING CHEMICAL

Benzene

(71-43-2)

SUPPORTING CHEMICAL

Toluene

(108-88-3)

SUPPORTING CHEMICAL

m-Xylene

(108-38-3)

SUPPORTING CHEMICAL Naphthalene

(91-20-3) Fish 96-h LC50 (mg/L)

No Adequate Data 1-26.7 (RA)

No Adequate Data 1-26.7 (RA)

4.3

5.3-15.6

5.4-26

2.6-26.7

1-10

Aquatic Invertebrates 48-h EC50 (mg/L)

No Adequate Data 1-17.2 (RA)

No Adequate Data 1-17.2 (RA)

2.7

10-17.2

11.5

8.5

1-10

Aquatic Plants 72-h EC50 (mg/L)

No Adequate Data 0.4-29 (RA)

No Adequate Data 0.4-29 (RA)

10.7

28-29

12.5 3.2-4.9

0.4

bold = experimental data (i.e., derived from testing); (RA) Read across.

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APPENDIX The following pages show:

• Table 12 with the range of concentrations for the 12 supporting chemicals in each of the 10 streams in the high benzene naphtha category. Note that the first row in the table shows the total number of components for that particular stream as presented in Appendix 2: Composition, pp.42–44 of the 2004 Category Summary by the submitter (identified as the “Revised Test Plan” under the Final Revision posted on December 22, 2004 at the following link: http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm ). The last row provides an estimate of the total percentage of stream components that may be attributed to the 12 supporting chemicals.

• Table 13 with data provided for some SIDS endpoints (see text) on three streams; two of which are in this category.

• Table 14 with representative structures of the sponsored substances and the supporting chemicals.

• Table 15 with Reference Sources for Supporting Chemical Data. • Description of origin of the high benzene naphthas category members and the associated

diagram are taken from the sponsor’s original final 2004 Category Summary (identified as “Revised Test Plan” under the Final Revision posted on December 22, 2004 at: http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm).

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Table 12. Predominant Components (% of total) of the Process Streams in the High Benzene Naphthas Category1

Subcategory I Subcategory II Subcategory III Chemical Name

Pyrolysis Gasoline

Recovered Oil From

Wastewater Treatment

Pyrolysis C6

Fraction

Pyrolysis C6 – C8 Fraction

Pyrolysis C5 – C6 Fraction

Hydro-treated C6 Fraction

Hydro-treated C6

– C7 Fraction

Hydro-treated C6

– C8 Fraction

Aromatic Extract

from Benzene

Extraction

Quench Loop Pyrolysis Oil

and Compressor Oil

Total # of Components2 58 (58?)3 17 13 5 7 15 5 3 13 Isoprene 0.6–10 ? 2.0–6.0 6.0 n-Pentane 10.0 ? 1.0 1,3-cyclopentadiene 1.0–20.0 ? 0.1–5.0 1.0 Isohexane 1.3 ? 4.0 10.0–20.0 Hexane 0–9.0 ? 1.0–5.0 6.0 2.0–15.0 Methylcyclopentane 4.9 ? 5.0–15.0 Benzene 15.0–62.0 ? 35.0–77.0 30.0–80.0 70.0 75.0–75.7 40.0–69.0 40.0–60.0 60.0–75.0 10.0–21.6 Toluene 17.4 ? 0.5–5.0 15.0–25.0 5.0 0.3 3.0–15.0 10.0–25.0 25.0–40.0 5.0–10.9 m-Xylene (“xylenes” in Table A2-1)

10.0 ? 1.0–10.0 1.0 1.5

Styrene 10.0 ? 1.0–10.0 10.0–15.0 Naphthalene 15.0 ? 4.3–10.0 Dicyclopentadiene 20.0 ? 1.0–5.0 3.7 Approx. Percentage of Total Covered by Predominant Components4

>80 ? 37-93 50-100 81 ~85 >60 50-85 100 33-60

Other Major Components (%)

~ 15 (>C9) ? 30 (C6 non-aromatics)

- - - 5-20 (C6) ~5-10 (C7)

20-26 (non-aromatic

HC)

- 38-50 (>C11)

1 Taken from Appendix 2: Composition, pp.42–44 of the 2004 Category Summary by the submitter (identified as the “Revised Test Plan” under the Final Revision posted on December 22, 2004 at the following link: http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm ).  Only the 12 chemicals identified as supporting chemicals are presented. 2 This row shows the total number of components in each category stream. 3 There are no specific composition data for this stream. It is expected to contain the components of pyrolysis gasoline. 4 These approximations show that – collectively - the 12 supporting chemicals represent a significant percentage of the streams in this category.

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Table 13. Predominant Components (% of total) of the Process Streams Tested for Some SIDS Endpoints in the High Benzene Naphthas Category1

Chemical Name Pyrolysis Gasoline

(Dripolene) Hydrotreated C6-8

Fraction3 Rerun Tower Overheads4

Total # of Components2 58 7 ? Isoprene 0.6–10 n-Pentane 10.0 7 1,3-cyclopentadiene 1.0–20.0 Isohexane 1.3 Hexane 0–9.0 2 Methylcyclopentane 4.9 Benzene 15.0–62.0 55 40 Toluene 17.4 25 13 m-Xylene (“xylenes” in Table A2-1)

10.0 10

Styrene 10.0 Naphthalene 15.0 Dicyclopentadiene 20.0 Approx. Percentage of Total Covered by Predominant Components

>80 ~100% 53

Other Major Components (%)

~ 15 (>C9) - 26 (C5) 20 (other)

1 Taken from Appendix 3, p.53 of the 2004 Category Summary by the submitter (identified as the “Revised Test Plan” under the Final Revision posted on December 22, 2004 at the following link: http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm ). 2 This row shows the total number of components in each category stream. 4The total percentage on p. 53 of the Category Summary is greater than 100% (109%). 5 Not a member of the category. Is considered a sufficiently similar mixture for read-across purposes in this hazard characterization

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Table 14. Representative Chemical Structures of Low Benzene Naphthas Category stream constituents and supporting chemicals1

Name CASRN Description and Representative Structures Sponsored Chemicals

Pyrolysis Gasoline 68606-10-0; 68921-67-5; 64742-83-2; 64742-91-2; 67891-79-6; 67891-80-9; 68476-45-9; 68526-77-2; 68606-28-0; 68955-29-3

CH3

(Pygas) consists predominantly of C5+ hydrocarbons produced by ethylene cracking furnaces. Typically, the combined concentrations of benzene, toluene, and dicyclopentadiene make up 50% or more of this stream. This stream is also called “Dripolene” (see test plan p. 19). Robust summaries for this stream are identified with this synonym.

Pyrolysis C5 – C6 Fraction

68955-29-3; 64742-83-2; 68956-52-5

CH3 CH3 The carbon number distribution for this stream is predominantly C5 – C6. One typical composition for this stream is reported as 70% benzene and 10% pentenes.

Pyrolysis C6 Fraction

68955-29-3; 64742-83-2; 68606-10-0

CH3

CH2

CH2

CH3

CH3 CH3 The carbon number distribution for this stream is predominantly C6. Reported compositions vary from 35 to 77% benzene, 0.5–5% toluene with the balance primarily C6 non-aromatics, which are expected to be largely unsaturated.

Pyrolysis C6-C8 Fraction

68475-70-7; 68955-29-3; 64742-83-2; 68476-45-9

CH3

CH3CH3 CH2

This stream has a carbon number distribution that is predominantly C6 – C8. The reported compositions are 30–80% benzene, 15–25% toluene, and 3–23% C8 aromatics.

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Table 14. Representative Chemical Structures of Low Benzene Naphthas Category stream constituents and supporting chemicals1

Name CASRN Description and Representative Structures Hydrotreated C6 Fraction

68410-97-9; 8030-30-6

CH3

CH3CH3 CH3

CH3

This stream is very similar in composition to the Pyrolysis C6 fraction except that the non-aromatics present in the hydrotreated stream are essentially all saturates. The reported composition for the Hydrotreated C6 stream indicates typical benzene content of 75%.

Hydrotreated C6 – C7 Fraction

68410-97-9; 64742-49-0; 64742-73-0; 68955-29-3

CH3CH3

CH3

CH3CH3 CH3

CH3

The carbon number distribution for this stream is predominantly C6 – C7 and the reported values indicate 40–70% benzene, and 3–15% toluene.

Hydrotreated C6-C8 Fraction

68410-97-9 CH3 CH3 CH3

The reported typical compositions for this stream are 40–60% benzene, 10–25% toluene, and 3–10% C8 aromatics.

Aromatic Extract from Benzene Extraction

64741-99-7 CH3

The carbon number distribution for this stream is predominantly C6 – C8. A reported typical concentration indicates 60–75% benzene, 25–40% toluene and 0–1% xylenes.

Quench Loop Pyrolysis Oil and Compressor Oil

69013-21-4

CH3

CH3

CH2

This stream represents higher boiling hydrocarbons that condense in the water quench system of an ethylene plant, typically at an ethylene unit cracking ethane, propane, or butane. The carbon number distribution for Pyoil is C4 (or even lower) through heavier hydrocarbons such as naphthalene or even heavier. The reported typical composition includes 10–22% benzene and 5–11% toluene.

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Table 14. Representative Chemical Structures of Low Benzene Naphthas Category stream constituents and supporting chemicals1

Name CASRN Description and Representative Structures Recovered Oil from Wastewater Treatment

68956-70-7 CH3

CH3 CH3

CH3

CH3 CH3 This stream can be expected to be of variable composition and made up largely of the components found in Pyrolysis Gasoline. No composition data or process-specific information have been reported

Supporting Chemicals 1,3-Butadiene, 2-methyl- (Isoprene)

78-79-5

CH2

CH2

CH3

n-Pentane 109-66-0

CH3 CH3 1,3-Cyclopentadiene

542-92-7

Pentane, 2-methyl- (Isohexane)

107-83-5

CH3 CH3

CH3

n-Hexane 110-54-3

CH3

CH3

Cyclopentane, methyl-

96-37-7 CH3

Benzene 71-43-2

Benzene, methyl- (Toluene)

108-88-3 CH3

Benzene, 1,3-dimethyl- (m-Xylene)

108-38-3 CH3 CH3

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Table 14. Representative Chemical Structures of Low Benzene Naphthas Category stream constituents and supporting chemicals1

Name CASRN Description and Representative Structures Benzene, ethenyl- (Styrene)

100-42-5 CH2

4,7-Methano-1H-indene, 3a,4,7,7a-tetrahydro- (Dicyclopentadiene)

77-73-6

Naphthalene 91-20-3

1Note on representative structures: The structures chosen for each category member were largely based on the compositional data presented on pp.42–44 of the 2004 Category Summary by the submitter (identified as the “Revised Test Plan” under the Final Revision posted on December 22, 2004 at the following link: http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm ). It should be understood that each category member consists of numerous hydrocarbon substances, well beyond the two to five compounds shown in the Appendix for most members. Moreover, the component process streams designated by the CASRNs below can be blended in various proportions when manufacturing each category member, which accounts for the wide range of compositions stated for several of the constituent compounds in each category member. For xylenes, the representative structure chosen was m-xylene, as it is a supporting chemical for the category.

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Table 15. Reference Sources for Supporting Chemical Data CASRN CHEMICAL SOURCE 78-79-5

Isoprene

Assessed as OECD HPV at SIAM 20: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=2d073e86-b448-45d4-9975-674f14c59bf8&idx=0 2008 Env/Health Canada screening assessment: http://www.ec.gc.ca/substances/ese/eng/challenge/batch2/batch2_78-79-5_en.pdf

108-88-3

Toluene

2000 ATSDR Tox Profile: http://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=161&tid=29 2005 EPA IRIS toxicological review: http://www.epa.gov/iris/subst/0118.htm EPA VCCEP Program: http://www.epa.gov/oppt/vccep/pubs/chemmain.html Assessed as OECD HPV at SIAM 11: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=e1315e8d-6a51-4a59-b4da-a3d24baade0d&idx=0 2003 EU Risk Assessment Report: http://ecb.jrc.ec.europa.eu/esis/

108-38-3 m-Xylene Assessed as OECD HPV at SIAM 16 in the xylenes category: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=64572a9c-b517-4f0a-a9c0-8953539bf5c9&idx=0

1330-20-7 Xylenes, mixed 2007 ATSDR Tox Profile: http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=296&tid=53 Assessed as OECD HPV at SIAM 16 in xylenes category: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=64572a9c-b517-4f0a-a9c0-8953539bf5c9&idx=0 2003 EPA IRIS assessment: http://www.epa.gov/ncea/iris/toxreviews/0270tr.pdf EPA VCCEP Program: http://www.epa.gov/oppt/vccep/pubs/chemmain.html

100-42-5

Styrene 2010 ATSDR draft Tox Profile: http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=421&tid=74 NIEHS CERHR review: http://cerhr.niehs.nih.gov/evals/styrene/Styrene_final.pdf EPA IRIS assessment: http://cfpub.epa.gov/ncea/iris/index.cfm?fuseaction=iris.showKeywordResults&maxrows=15&startrow=1&textfield=100-42-5&searchtype=irisdata Assessed as OECD HPV at SIAM 4: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=96240163-414e-4da4-8f1f-82dce4c16be2&idx=0 2002 EU Risk Assessment Report: http://ecb.jrc.ec.europa.eu/esis/

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Table 15. Reference Sources for Supporting Chemical Data CASRN CHEMICAL SOURCE 91-20-3 Naphthalene 2005 ATSDR Tox Profile:

http://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=240&tid=43 EPA IRIS assessment: http://www.epa.gov/iris/toxreviews/0436tr.pdf Assessed as OECD HPV at SIAM 5: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=6e0025b7-e1b2-459d-b61e-54db1a4016b4&idx=0

109-66-0 n-Pentane Assessed as OECD HPV at SIAM 13 and at SIAM 26 in the C5 aliphatic hydrocarbon solvents category; http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=ed4e1315-0f28-4a6f-9563-9a88b20a66bf&idx=0 2003 EU RAR: http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/n-pentanereport043.pdf

542-92-7 1,3-Cyclopentadiene HPV submission for this category: http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm Reliable screening Information not readily available (Note: This chemical was not sponsored in the US HPV program and was subject to a Section 8(a) rule in 2007 (see http://www.epa.gov/fedrgstr/EPA-TOX/2006/August/Day-16/t13479.htm )

107-83-5 Isohexane HPV submission for this category: http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm

110-54-3 n-Hexane 2005 EPA IRIS assessment: http://www.epa.gov/ncea/iris/toxreviews/0486tr.pdf 1999 ATSDR draft Tox Profile: http://www.atsdr.cdc.gov/ToxProfiles/tp113.pdf

96-37-7 Methylcyclopentane HPV submission for this category: http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm

71-43-2 Benzene 2005 EPA IRIS assessment: http://www.epa.gov/ncea/iris/toxreviews/0276tr.pdf (2002, noncancer) http://www.epa.gov/ncea/iris/supdocs/0276index.html (other IRIS benzene documents, including cancer) 2007 ATSDR draft Tox Profile: http://www.atsdr.cdc.gov/ToxProfiles/tp3.pdf Assessed as OECD HPV at SIAM 21: http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/benzenereport063.pdf

77-73-6 Dicyclopentadiene Assessed as OECD HPV at SIAM 7: http://webnet.oecd.org/hpv/UI/SIDS_Details.aspx?Key=c1669b2f-fe19-4ff0-8761-4d0e436e73e2&idx=0

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Origin of High Benzene Naphtha Streams The following diagram is taken from p. 41 of the 2004 Category Summary by the submitter (identified as the “Revised Test Plan” under the Final Revision posted on December 22, 2004 at the following link: http://www.epa.gov/oppt/chemrtk/pubs/summaries/hibenznp/c13436tc.htm ).