environmental ghs for beginners

Environmental GHS for Beginners

- Substances -

-Mixtures –

- Hazard Communication -

GHS Classification of Substances

Scope & Rationale

• Intrinsic hazards to aquatic organisms• 3 acute categories & 4 chronic categories applied

independently – basis for use in all regulatory systems

• Acute hazard category assigned using acute data• Chronic hazard category assigned using acute

data in conjunction with potential for long-term exposure (i.e. lack of rapid degradability) and/or potential to bioaccumulate

• Declassification of chronic hazard possible through use of chronic data

Data Elements for Classification

• Acute aquatic toxicity – representative species e.g.– fish 96 h LC50; crustacea 48 h EC50; algae 72 or 96 h

ErC50

• Bioaccumulation potential– log Kow or Bioconcentration Factor (BCF)

• Rapid degradability– Ready biodegradability; BOD5/COD ≥ 0.5; other

evidence for rapid degradation

• Chronic toxicity – relevant species e.g.– Fish Early Life Stage; Daphnia reproduction; Algal

Growth Inhibition

Acute I

• 96 h LC50 (for fish) 1 mg/L and/or• 48 h EC50 (for crustacea) 1 mg/L and/or• 72 or 96 h ErC50 (for 1 mg/L

algae or other aquatic plants)

• Acute I may be subdivided for some regulatory systems to include a lower band at L(E)C50

0.1mg/L

Acute II

• 96 h LC50 (for fish) >1 - 10 mg/L and/or

• 48 h EC50 (for crustacea) >1 - 10 mg/L and/or

• 72 or 96 h ErC50 (for >1 - 10 mg/L algae or other aquatic plants)

Acute III




• Some regulatory systems may extend this range

beyond an L(E)C50 of 100 mg/L through the introduction of another category

Chronic I

• 96 h LC50 (for fish) 1 mg/L and/or

• 48 h EC50 (for crustacea) 1 mg/L and/or

• 72 or 96 h ErC50 (for 1 mg/L algae or other aquatic plants)

AND• the substance is not rapidly degradable and/or

the log Kow 4 (unless the experimentally determined BCF <500).

Chronic II




AND• the substance is not rapidly degradable and/or the

log Kow 4 (unless the experimentally determined BCF <500)

• unless the chronic toxicity NOECs are >1 mg/L for the species showing acute toxicity

Chronic III

• 96 h LC50 (for fish) >10 - 100 mg/L and/or• 48 h EC50 (for crustacea) >10 - 100 mg/L and/or• 72 or 96 h ErC50 (for >10 - 100 mg/L

algae or other aquatic plants) AND

• the substance is not rapidly degradable and/or the log Kow 4 (unless the experimentally determined BCF <500)

• unless the chronic toxicity NOECs are >1 mg/L for the species showing acute toxicity

Chronic IV

• ‘Safety Net’ classification for poorly soluble substances (normally substances with solubility >1 mg/L)

• no acute toxicity at levels up to the water solubility, AND

• not rapidly degradable, AND

• log Kow 4

• Classified unless – experimentally determined BCF <500, OR– chronic toxicity NOECs >1 mg/L (or > solubility), OR – evidence of rapid degradation in the environment

Proposal on chronic hazards

• In the adoption process at OECD.

• To be submitted to the UN Sub-Committee of Experts on the GHS

• Surrogate chronic system: acute + persistency or bioacumulation potential

• Surrogate system to be superseded when experimental chronic NOECs/ECx values are available

Proposed flowchart submitted to the UN Sub-Committee of Experts

Notes

• Provisional classification if acute toxicity data are available for <3 species

• Declassification from chronic categories II & III requires chronic data with NOECs >1 mg/L for species in which acute toxicity data resulted in classification

• Declassification from chronic class IV requires chronic data with NOECs > water solubility

Examples• Substance X

– Fish LC50 9.7mg/L; Daphnia EC50 20mg/L; Algae ErC50 82mg/L

– Biodegradability <5% in OECD 301– log Kow 2.7

• Classification– Acute toxicity in range >1 - 10 mg/L– Not rapidly degradable (therefore log Kow < 4 is not

taken into account)– No BCF or chronic toxicity data– Therefore assign:

Acute II & Chronic II

Variations on Substance X• Substance X – variation 1


– Daphnia reproduction study NOEC >1mg/l– Biodegradability <5% in OECD 301– log Kow 2.7

• Classification– Acute toxicity in range >1 - 10 mg/L (fish)– Not rapidly degradable (therefore log Kow <4 is not

taken into account)– No BCF, but chronic NOEC >1 mg/L (Daphnia)– Therefore assign:

Acute II & Chronic II would need fish NOEC to declassify



– Fish Early Life Stage study NOEC > 1mg/l– Biodegradability <5% in OECD 301– log Kow 2.7

• Classification– Acute toxicity in range >1 - 10 mg/L (fish)– Not rapidly degradable (therefore log Kow <4 is not

taken into account)– No BCF, but chronic NOEC >1 mg/L (fish)– Therefore assign:

Acute II not Chronic II due to fish NOEC >1 mg/l

Variations on Substance X

• Substance X – variation 3– Fish LC50 9.7mg/L; Daphnia EC50 20mg/L; Algae ErC50

82mg/L– Biodegradability – no data

– log Kow 2.7

• Classification– Acute toxicity in range >1 - 10 mg/L (fish)

– No data for rapid degradability, and log Kow <4

– No BCF or chronic toxicity data– Therefore assign:

Acute II & Chronic II as assume not rapidly degradable in absence of data


– Fish LC50 no data; Daphnia EC50 20mg/L; Algae ErC50 82mg/L

– Biodegradability <5% in OECD 301– log Kow 2.7

• Classification– Acute toxicity in range >10 - 100 mg/L (Daphnia &

Algae)– Not rapidly degradable (therefore log Kow <4 is not taken

into account)– No BCF or chronic toxicity data– Therefore assign:

Provisional Classification Acute III; Chronic III as classification based on data from 2, not 3 species


– Fish LC50, Daphnia EC50 and Algae ErC50 all above water solubility

– Water solubility 50 mg/L– Biodegradability <5% in OECD 301– log Kow 2.7

• Classification– Acute toxicity above water solubility– Not rapidly degradable, but log Kow <4– No BCF or chronic toxicity data– Therefore assign:

No Classification



– Water solubility >1 mg/L– Biodegradability <5% in OECD 301– log Kow 2.7

• Classification– Considered poorly soluble & acute toxicity above water

solubility– Not rapidly degradable, but log Kow <4– No BCF or chronic toxicity data– Therefore assign:

No Classification



– Water solubility <1 mg/L– Biodegradability <5% in OECD 301– log Kow 5

• Classification– Considered poorly soluble & acute toxicity above water

solubility– Not rapidly degradable and log Kow >4– No BCF or chronic toxicity data– Therefore assign:

Chronic IV

GHS Classification of Mixtures

GHS - Mixtures Options

• Testing• Bridging• Calculation

– Additivity– Summation (including M-factors)

• Examples

• Classification based on testing of mixture

• Classification based on bridging principles

• Classification based on calculation.

Hierarchy of Data Acceptability

Testing

• GHS allows classification based on testing of mixtures but only for toxicity:

(Toxicity)

0

10

20

30

40

50

60

70

80

90

100

1 10 100

LC50

Concentration (mg/l)

Res

pons

e (%

)

Testing not allowed• Biodegradation and bioaccumulation are used to

derive chronic classification classes.• Testing is not allowed for biodegradation and

bioaccumulation.• So, chronic classification can only be assigned

using bridging or calculation methods.

Time (days)% T

heor

etic

al C

O2

prod

uced

(Biodegradation)

Cfish

Cwater

(Bioconcentration)

Testing allowed

• The toxicity of mixtures can be tested using the same methodology as used for single substances, setting up a range of concentrations to determine the LC50 or EC50,

1 10 100

LC50

Concentration of mixture (mg/l)

Res

pons

e (%

)

100

0

but there may be additional complications……..

Testing Issues

• Components with differing solubility:– undissolved components may cause

physical interference (fouling), which is excluded from measures of toxicity.

– WAF approach is the answer.

• Confirmation of exposure concentrations:– May be impractical to monitor the

concentration of all components. – Need for Best Professional Judgement as to

what should be measured.

Bridging

• Provides for the situation in which the mixture has not been tested, but a similar mixture has been tested. ‘Similar’ can be defined in terms of:– Dilution– Batching– Concentration of Chronic I or Acute I components– Interpolation– Substantially similar mixtures

Bridging I - dilution

Mixture A(Tested)

Mixture orSubstance B

(Classification known)

Mixture of A+B (=C)(Not Tested)

=

+

Bridging - dilution

• If ‘B’ is water or is totally non-toxic, then classification of ‘C’ can be calculated – eg if LC50 of ‘A’ is 6 mg/l (Acute II), and it is diluted 2x with water, then

toxicity of ‘C’ is estimated to be 12 mg/l (Acute III)

• If ‘B’ is classified but has a hazard classification less than the least toxic component of ‘A’, then ‘C’ can be classified as for ‘A’.– eg if LC50 of ‘B’ is 15 mg/l (Acute III) and least toxic component of ‘A’ has

an LC50 of 6 mg/l (Acute II), then ‘C’ can be classified as Acute II

=

A B C+ =

Bridging II - batching

• The classification of two batches of product from one manufacturer is assumed to be the same………

………….unless there is reason to believe that variation (in, for

example, feedstock, manufacturing process) will have affected the classification.

Bridging III - concentration

• If a component causes a mixture to be classified as Acute I or Chronic I, and that component is concentrated, the new mixture will also be classified as Acute I or Chronic I.

Bridging IV - interpolation

• If Mixture C contains the same components as Mixtures A & B, in quantities intermediate between those in A & B…..

……. and if Mixtures A & B have the same classification…..

…….then Mixture C will also have the same classification

Bridging – interpolation example

90% 10%

Mixture AAcute II

30% 70%

Mixture BAcute II

60% 40%

Mixture CInterpolate as Acute II

Bridging V - substantially similar mixtures

• If two mixtures differ in one component, but otherwise have the same composition……

…… and if the components that differ have the same classification……

…… then the two mixtures can be assumed to have the same

classification.

• Thus, if the toxicity of one of the mixtures has been tested and a classification derived, the classification of the second mixture can be assumed to be the same as that of the first.

Bridging – substantially similar mixtures, example

Mixture ATested - Acute II

Mixture BNot tested

If Component ‘m’ has the same classification as Component ‘n’, then Mixture B should be

Acute II, as is Mixture A. If toxicity of ‘m’ and ‘n’ differs, bridging is not possible.

Component p, 10%Component j, 80%

Component n,10%

Component m,10%

Component p, 10%Component j, 80%

Calculations

• Summation

• Additivity

Calculation – summation (acute)

(all components toxicity > 0.1 mg/l)

Components classified as: Mixture is classified as:

Acute I >25% Acute I

(10 x Acute I) + Acute II >25% Acute II

(100 x Acute I)+(10 x Acute II)+Acute III

>25% Acute III

Calculation – summation (acute)(some components toxic at 0.1 mg/l)


Acute I x M* >25% Acute I

(M x 10 x Acute I) + Acute II >25% Acute II

(M x 100 x Acute I)+(10 x Acute II)+Acute III

>25% Acute III

* M is a multiplying factor to take account of the toxic contribution of components toxic at 0.1 mg/l. It is calculated separately for each Acute I component.

Calculation – summation, M-factor

L(E)C50 value Multiplying factor (M)

0.1<L(E)C50 1 1

0.01<L(E)C500.1 10

0.001<L(E)C500.01 100

0.0001<L(E)C500.001 1000

0.00001<L(E)C500.0001 10000

(continue in factor 10 intervals)

Summation example I (data)

Component Classification* Concentration (wt %)

A Acute II 3

B Acute II 10

C No classification

87

* All components are readily biodegradable and have log Kow<4

Summation example I (acute analysis)

• Apply summation to all components

– No components toxic at 0.1 mg/l, so no M-factor to apply

acute I components = 0, which is <25%, so acute I does not apply

(10 x acute I) + acute II = 13%, which is <25%, so acute II does not apply.

(100 x acute I) + (10 x acute II) + acute III=130%, which is >25%, so acute III applies.

Calculation – summation (chronic)(some components toxic at 0.1 mg/l)


Chronic I x M* >25% Chronic I

(M x 10 x Chronic I) + Chronic II

>25% Chronic II

(M x 100 x Chronic I)+(10 x Chronic II)+ Chronic III

>25% Chronic III

Chronic I + Chronic II + Chronic III + Chronic IV

>25% Chronic IV

* Same M-factor as for acute

Summation example II (data)

Component Classification Concentration (wt %)

A Acute II Chronic II

3

B Acute III Chronic III

10

C No classification

87

Summation example II (chronic analysis)

• Apply summation to all components*

– No components toxic at 0.1 mg/l, so no M-factor to apply

chronic I components = 0, which is <25%, so chronic I does not apply

(10 x chronic I) + chronic II = 13%, which is <25%, so chronic II does not apply.

(100 x chronic I) + (10 x chronic II) + chronic III=130%, which is >25%, so chronic III applies.

* Acute classification is ignored in this example

Summation example III (data)Component Classification L(E)C50

(mg/l)Concentration

(wt %)M-factor

A Acute I 0.003 0.009 100

B Acute III, Chronic III

n/r 10 -

C No classification

n/r 80.991 -

D Acute II n/r 5 -

E Acute I, Chronic I

0.4 4 1

n/r – not relevant to summation

Acute classification (M x acute I) =

(100x0.009)+(1x4)=4.9, which is <25%, so acute I does not apply

(10 x ( (M x acute I)) + acute II = (10 x 4.9)+5=54%, which is >25%, so acute II applies.

• Since acute II applies, no need to analyse for acute III.

Summation Example III (acute and chronic analysis)

Component

Classification

L(E)C50

(mg/l)

Concentration (wt

%)

M-factor

A Acute I 0.003

0.009 100

B Acute III, Chronic III

n/r 10 -

C No classificati

on

n/r 80.991 -

D Acute II n/r 5 -


0.4 4 1

Chronic classification (M x chronic I) = 1x4=4,

which is <25%, so chronic I does not apply

(M x 10 x chronic I) + chronic II = 40%, which is >25%, so chronic II applies.

• Since chronic II applies, no need to analyse for chronic III.

Overall classification is acute II, chronic II

Summation Example III (acute and chronic analysis)

Component

Classification

LC50

(mg/l)

Concentration (wt

%)

M-factor

A Acute I 0.003

0.009 100

B Acute III, Chronic

III

n/r 10 -

C No classifica

tion

n/r 80.991 -

D Acute II n/r 5 -


0.4 4 1

However, …………..

…………… in some jurisdictions it may be necessary to consider the Summation method, as described so far, and the Additivity method…………..and take the more conservative classification.

Calculations - additivity

• The additivity formula should be used for components for which adequate data exist but which have not been classified. Toxicity derived by the additivity formula should be used to derive a classification for such components which is then used in the summation method.

• In the EU, the additivity formula should be redundant, since if toxicity data exist they should be used to classify the substance.

• However, if both methods are used, the method yielding the most conservative result should be used.

Calculation – additivity formula

Ci = Concentration of component i (weight percentage)L(E)C50i = LC50 or EC50 for component i (mg/l)n = number of components with adequate, but unused, toxicity dataL(E)C50m = L(E)C50 of the part of the mixture with test data which have not been used in classification

L(E)C50m

Ci

L(E)C50i

n=

Ci

Calculation – additivity formula rearranged

L(E)C50m =Ci

L(E)C50i

n

Ci /Ci = Concentration of component i (weight percentage)L(E)C50i = LC50 or EC50 for component i (mg/l)n = number of components with adequate, but unused, toxicity dataL(E)C50m = L(E)C50 of the part of the mixture with test data which have not been used in classification

Additivity example I (data)

Component Classification LC50 (mg/l) Concentration (wt %)

A - 2 3

B - 5 10

C No classification

- 87

* Assume components ‘A’ & ‘B’ are readily biodegradable and have log Kow<4

Additivity example I (analysis)

• Apply additivity to estimate combined toxicity of components ‘A’ and ‘B’– L(E)C50(A+B)= (3+10)/ ((3/2)+(10/5))

= 13/3.5= 3.7 mg/l ( Acute II)

• Apply summation formula to all components– There are no Acute I components Acute II = 13%, since this is <25%, acute II does not apply. (10 x Acute II) + Acute III = 130%, since this is >25%, acute III

applies.

• Additivity classification is Acute III. Since all components are readily biodegradable and not bioaccumulative (log Kow<4), chronic classification does not apply.

• It is now necessary to check whether the Summation formula would have given a more conservative classification…………

Component

Classification

LC50 (mg/l)

Concentration (wt %)

A - 2 3

B - 5 10

C No classification

- 87

L(E)C50m =Ci

L(E)C50i

nCi /L(E)C50m =

Ci

L(E)C50i

nCi / Ci

L(E)C50i

n

Ci

L(E)C50i

n

nCi /

Additivity example I (acute analysis- Step II)

• The data should have been used to classify both ‘A’ and ‘B’ as acute II.

• Summation formula then gives: Acute II = (3+10)=13, which is <25%, so acute II does not apply. (10 x Acute II) + Acute III = (10x13)=130%, since this is >25%,

acute III applies.– Summation classification is acute III.

• Summation and additivity methods give same classification so no choice is required, the classification is acute III.

Component

Classification

LC50 (mg/l)


A - 2 3

B - 5 10

C No classification

- 87

Additivity example II (data)

Comp-onent

Classification L(E)C50 (mg/l)

Concen-tration (wt %)

M-factor

Biodeg/Bioaccum

A - 0.03 3 10 Rapidly/log Kow<4

B - 5 10 - Rapidly/log Kow<4

C No classification - 73.6 -

D - 0.006 1 100 Rapidly/log Kow>4

E Acute II, Chronic II

n/r 10 -

F Acute I 0.02 2.4 10 -

Additivity Example II (acute and chronic

analysis- Step I)

Toxicity of unclassified components• Apply additivity formula to estimate combined toxicity of

‘unclassified’ components (‘A’, ‘B’ and ‘D’): (3+10+1)/ (3/0.03)+(10/5)+(1/0.006)=0.052 mg/l

• Note additivity calculations only calculate acute toxicity, biodegradability and bioaccumulation information is taken into account in the subsequent Summation calculation. In this subsequent calculation, ‘component’ ‘ABD’ is considered as if it has a chronic classification because one of its components (‘D’) has a chronic I.

Comp-onent

Classi-fication

LC50 (mg/l)


M-factor

Biodeg/Bioaccum

A - 0.03 3 10 Rapidly/logKow<4

B - 5 10 - Rapidly/logKow<4

C No classi-fication

- 73.6 -

D - 0.006 1 100 Rapidly/logKow>4


n/r 10 -

F Acute I 0.02 2.4 10 -

L(E)C50m =Ci

L(E)C50i

nCi /L(E)C50m =

Ci

L(E)C50i

nCi / Ci

L(E)C50i

n

Ci

L(E)C50i

n

nCi /

Additivity example II (acute and chronic analysis- Step II)

Component Classification L(E)C50 (mg/l)


M-factor

ABD Acute I, Chronic I

0.052 14 10

C No classification

- 73.6 -


n/r 10 -

F Acute I 0.02 2.4 10

The data table can now be simplified:

And the Summation formula can be applied….

Additivity example II (acute and chronic analysis- Step III)

• Acute classification (M x acute I) = (10x14)+(10x2.4)=144, which is >25%, so acute I

applies– Since acute I applies there is no need to analyse for acute II or III.

• Chronic classification (M x chronic I) = 10x14=140, which is >25%, so chronic I applies.– Since chronic I applies, no need to analyse for chronic II or III.

• Additivity classification is acute I, chronic I• As usual, it is necessary to check whether, if all

components had been individually classified, the Summation formula would have given a more conservative classification…………

Component Classification LC50 (mg/l)


M-factor

ABD Acute I, Chronic I

0.052 14 10

C No classification - 73.6 -


n/r 10 -

F Acute I 0.02 2.4 10

Additivity Example II (acute and chronic analysis - Step IV)

• The data should have been used to classify ‘A’ as acute I (M-factor of 10); ‘B’ as acute II; ‘D’ as acute I & chronic I (M-factor of 100)

• Summation formula then gives: (M x Acute I) = (10x3)+(1x100)+(10x2.4)=154%, since this is

>25%, Acute I applies. (M x chronic I) = (10x3)+(100x1)=130, which is >25%, so chronic I

applies.– Summation classification is acute I, chronic I.

• Summation and additivity methods give same classification so no choice is required, classification is acute I, chronic I.

Comp-onent

Classi-fication

LC50 (mg/l)


M-factor

Biodeg/Bioaccum

A - 0.03 3 10 Rapidly/logKow<4

B - 5 10 - Rapidly/logKow<4

C No classi-fication

- 73.6 -

D - 0.006 1 100 Rapidly/logKow>4


n/r 10 -

F Acute I 0.02 2.4 10 -

Components with missing data

• If a mixture contains components without data (either toxicity values or classification information), the mixture is classified on the basis of those components with data with the additional statement: ‘x% of the mixture consists of component(s) of unknown hazard to the aquatic environment’

Hazard Communication

Hazard Communication

Current GHS

Hazard Communication - AcuteAcute I Acute II Acute III No

classification

Symbol Fish & tree None None None

Signal word Warning None None None

Phrase Very toxic to aquatic life

Toxic to aquatic life

Harmful to aquatic life

None

N, R50 No change

NewDoes not apply to

packaged goods

New Does not apply to

packaged goods

cf Existing legislation

Hazard Communication - Chronic

Chronic I Chronic II Chronic III Chronic IV No classificati

on

Symbol Fish & tree Fish & tree None None None

Signal word Warning None None None None

Phrase Very toxic to aquatic life with long

lasting effects

Toxic to aquatic life with long

lasting effects

Harmful to aquatic life with long

lasting effects

May cause long lasting

effects to aquatic life

None

N, R50/53N, R51/53

R52/53cf Existing legislation

R53No

change

GHS Differences from EU classification legislation

Key Areas of Difference

• If you have been classifying according to 67/548 & 1999/45/EC you’ll recognise most of the GHS. The major areas of difference that you need to take into account are:– Criteria used for classification

• Endpoints• Bioconcentration• Degradation• Escape clause• Categories

– Methods for dealing with mixtures– Hazard Communication

Endpoints

Change Potential Impact

48 h EC50 (Daphnia) becomes 48 h EC50

(Crustacea)

This has been practice in EU for some time.

72 h IC50 (algae) becomes 72 or 96 h IrC50 (algae), provided exponential growth in the control vessels

Growth rate alone may alter some classifications (Note, there is still some debate around this point).

Acceptance of 96 h data has been EU practice for some time.

Bioconcentration


Bioconcentration potential cut-offs of log Kow<3 and BCF<100 become log Kow<4 and BCF<500

Some substances may no longer require classification

Bioconcentration was not considered as a trigger for chronic toxicity for substances with acute toxicity > 10 mg/l. Under GHS bioconcentration will be considered for all substances.

Some previously non-classified substances may require classification.

Degradation


Readily degradable become rapidly degradable

Abiotic degradation has been rarely applied in the past. Degradation criteria have not changed under GHS, so the change of phrase does not indicate a significant change.

Inherent test data cannot be used to declassify

Declassification based on inherent data has not commonly been applied in the past, so impact is likely to be small.

Escape Clause (No need for chronic classification if chronic toxicity data

indicate no toxicity at 1 mg/l)


Under 67/548 applied to substances with acute toxicity > 10 mg/l, under GHS applies at > 1 mg/l.

Some previously classified substances may no longer need classification.

Acceptability of test species may be more restricted. 67/548 states eg Daphnia, but for substances toxic in the range 10-100 mg/l, recent practice has been to require data for all trophic levels showing acute toxicity at <100 mg/l. Under GHS, data showing lack of toxicity are required, but it is not stated on which species.

Restriction on test species acceptability has been recent practice in the EU, but since this guidance is new, it has not been performed routinely on all test substances. If the ‘new’ practice is applied under GHS, it will be more costly to activate the escape clause.

Categories


There is no equivalent in GHS to R52 classification

None, R52 alone has never been applied.

Introduction of Acute II and Acute III

More substances will be classified.

Methods for Dealing with Mixtures

• GHS adopts a method that is very similar to that used in the Prep’s Directive. The major differences are:– More prescriptive description of bridging principles– Adoption of ‘M-factors’ to take account of the greater

toxicity of substances toxic at <1 mg/l– To calculate classifications, the Summation method

(akin to the Prep’s Dir methodology) is supplemented by the Additivity method

environmental ghs for beginners

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