Migration of Migration of PerfluorochemicalsPerfluorochemicals

From Food Contact MaterialsFrom Food Contact Materials

Tim Begley

Office of Regulatory ScienceCenter for Food Safety and Applied Nutrition

Food and Drug Administration

Why are we interested in Why are we interested in perfluoroperfluoro chemical chemical

migration?migration?

• Perfluoro chemicals found in human serum (Olsen et al. 1999) . Occupational exposure.

• May 2000, 3M Company announce phase out of perfluorooctyl chemistry.

• August 2002, marine mammals, fishes and birds (Kannan et al. Environ. Sci. Technol.)

• Elderly in Seatle WA are found to have perfluorochemicals in their serum (Olsen et al. 2003) .

Why are we interested in Why are we interested in perfluoroperfluoro

chemical migration?chemical migration?

• PFOA is biopersistent / bioaccumulative

• Half-life in human serum may be 4.4 years (Butenhoff et al. 2004).

• Potential concerns for carcinogenesis; developmental/reproductive and immunotoxic.

• Many fluorochemicals regulated for food-contact contain PFOA as an impurity and/or have chemical moieties similar to PFOA.

22--perfluorooctylethanol or (8:2 telomer alcohol) has perfluorooctylethanol or (8:2 telomer alcohol) has

been shown to biodegrade to PFOAbeen shown to biodegrade to PFOA

DinglasanDinglasan, M.J.A., et al., 2004, Environmental Science and Technology, 38, M.J.A., et al., 2004, Environmental Science and Technology, 38, 2857, 2857--2864.2864.

PerfluorooctanoicPerfluorooctanoic acid = PFOAacid = PFOA

Structures of Structures of perfluorochemicalsperfluorochemicals

found in human serumfound in human serum

O

HO

FF

FF

FF

FF

FF

FF

F

FF

C

FF

F F

F F

F F

F F

F F

FF

F

F

F

S

O

O

-O

••PerfluorooctanoicPerfluorooctanoic acid = PFOAacid = PFOA

••PerfluoroocatanesulfonatePerfluoroocatanesulfonate = PFOS= PFOS

Typical Commercial Products Potentially Made Typical Commercial Products Potentially Made

with with FluorochemicalsFluorochemicals

Food package types that contain Food package types that contain

fluorochemicalsfluorochemicals

PolymersPolymers

PaperPapermicrowave popcornmicrowave popcorn

muffin bagsmuffin bags

frenchfrench fry bagsfry bags

pizza linerspizza liners

sandwich wrapperssandwich wrappers

burger/pizza boxesburger/pizza boxes

cookwarecookware

tubingtubing

gasketsgaskets

Historical Regulation in the USAHistorical Regulation in the USA

•• 1962 1962 PTFE for cookwarePTFE for cookware

•• 19841984 perfluorochemicalperfluorochemical elastomerselastomers

•• 19581958 paper coatings (priorpaper coatings (prior--sanctioned)sanctioned)

•• 19621962 11stst paper coatings (petition)paper coatings (petition)

Where are Where are perfluorochemicalsperfluorochemicals for for

paper regulated?paper regulated?

•• In US approximately 15 materials are In US approximately 15 materials are regulatedregulated

•• BfR also has a number of BfR also has a number of perfluoroperfluorochemicals regulatedchemicals regulated

Types of Types of perfluorochemicalsperfluorochemicals

added to food contact paperadded to food contact paper

•• PerfluoroPerfluoro telomer type telomer type

CC66 CC88 CC1010 CC1212 CC1414 basedbased

•• Polymeric typePolymeric type

Typical structures of Typical structures of perfluoroperfluoro telomer based telomer based

paper coatingspaper coatings

NH4+

POO

O

-OS

O

O N

F

FF

F F

FF

F

F

F

F

F

F

FF

FF

SOO

N

F

F

F

F

F

F

F

F

F

F

F

F

F

FF

F F

S

S

F

FF

HF

FF

F

F

FF

FF

F

FF

F

FF

F

F

F

FF

F F

F

F

F

FF

FF

F

O

O

OO

P

NH4+

F

FF

F

FF

F

F

F

FF

F

F

F

F

F

F

FFF

F F

F

F

F

F

F

F

F

F

F

F

F F

O

P

O

O

O

H2N

OH

OH

m/zm/z = 889= 889

m/zm/z 12021202

m/zm/z =1021=1021

Analysis of PTFE Cookware for PFOAAnalysis of PTFE Cookware for PFOA

Summary of PFOA analysis of some Summary of PFOA analysis of some

polymerspolymers

NDNDFEP TubingFEP Tubing

18001800PTFE Sealant TapePTFE Sealant Tape

44Dental TapeDental Tape

33Dental FlossDental Floss

44--7575PTFE CookwarePTFE Cookware

Conc. PFOAConc. PFOA µµg/kgg/kgMaterialMaterial

Does PFOA migrate from PTFE Does PFOA migrate from PTFE

during cooking?during cooking?

•• Use PTFE sealant film for migration test.Use PTFE sealant film for migration test.

•• PTFE film has CPTFE film has Cp0p0 = 1.8 mg/kg= 1.8 mg/kg

•• Test for migration at 100Test for migration at 100°°C and 175C and 175°°C C

into water and oil.into water and oil.

Typical LCMS analysis for PFOA Typical LCMS analysis for PFOA

migrating from PTFE into Miglyol at migrating from PTFE into Miglyol at

100100°°CC

400

600

800

1000

1200

1400

0 2 4 6 8

Time (min)

Rela

tive S

IM Inte

nsity

PFOA

Migration of PFOA from PTFE sealant Migration of PFOA from PTFE sealant

film after 2hrs at cooking temperaturesfilm after 2hrs at cooking temperatures

Mt (PFOA)

100°C Water 150 ng/dm2 ( 1.6 ±±±± 0.4µg/kg)

Miglyol 120 ng/dm2 (1.3 ±±±±.07 µg/kg)

175°C Miglyol 710 ng/dm2 (7.7±±±± 0.1 µg/kg)

Fractional PFOA Migration from PTFEFractional PFOA Migration from PTFE

•• Fractional Migration Fractional Migration oiloil at 175at 175°°C MC Mtt/M/M∞∞= 17%= 17%

•• Fractional Migration Fractional Migration waterwater at 100at 100°°C MC Mtt/M/M∞∞= 4%= 4%

Simulated Loss of PFOA from Cookware based on

Fractional Migration, Potential Values

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 10 20 30 40

Number of uses

ng

/cm

2 i

n p

oly

me

r

0

0.02

0.04

0.06

0.08

0.1

0.12

ng

/g i

nto

Fo

od

Water

Oil

CP0 = 75 ng/g

Simulated Loss of PFOA from Cookware based on

Fractional Migration, Potential Values

0

0.05

0.1

0.15

0.2

0.25

0.3

0 10 20 30 40

Number of uses

ng

/cm

2 in

po

lym

er

Sinclair et al., Environ. Sci. Tech. 2007

at 179° - 233°C

Does PTFE Degrade to PFOA at High Temperature?Does PTFE Degrade to PFOA at High Temperature?

•• FDA, No detectable increase in PFOA in PTFEFDA, No detectable increase in PFOA in PTFE

•• Sinclair et al., Environ. Sinclair et al., Environ. SciSci. Tech. 2007, No . Tech. 2007, No

PFOAPFOA

Temperature Respnse for Heating an Empty 28cm

PTFE Coated Pan with a Flame

0

50

100

150

200

250

300

350

0 50 100 150 200 250 300 350

Time (seconds)

Tem

pera

ture

°C

32

132

232

332

432

532

632

Tem

pera

ture

°F

Smoke point for oils

FluorochemicalsFluorochemicals for Food Contact Paperfor Food Contact Paper

Fluorochemical Paper coatingsFluorochemical Paper coatings

•• Fluorochemical paper concentrations can Fluorochemical paper concentrations can be up to 0.5% or 5000 mg/kg.be up to 0.5% or 5000 mg/kg.

•• Temperature range for paper applications Temperature range for paper applications --55°°C C –– 200+200+°°C. C.

•• Most Most perfluoroperfluoro telomertelomer based paper based paper treatments have treatments have molecular weights >1000molecular weights >1000but the but the molecular sizemolecular size is similar to much is similar to much smaller molecules.smaller molecules.

F versus H

MW = 1121 MW = 510

Migration of chemicals with MW > 1000 ?Migration of chemicals with MW > 1000 ?

MW = 1121

Molecular Area = 558Ǻ2

MW = 510

Molecular Area = 541Ǻ2

Molecular Volume = 609Ǻ3 Molecular Volume = 530Ǻ3

C71H141 MW = 997 Molecular Volume = 1225Ǻ3

FF HH

Is PFOA in Is PFOA in PerfluorochemicalPerfluorochemical Paper Paper

Coatings and treated Paper Products?Coatings and treated Paper Products?

Concentration of PFOA in Concentration of PFOA in PerfluoroPerfluoro Paper Paper

Coatings and Paper ProductsCoatings and Paper Products

88 88 -- 160160PerfluoroPerfluoro paper coating paper coating

(not applied)(not applied)

0.90.9Hash brown potato bagHash brown potato bag

0.5 0.5 –– 1.21.2Sub Sandwich wrapperSub Sandwich wrapper

0.50.5Muffin bagMuffin bag

0.30.3Popcorn bagsPopcorn bags

CCp0p0 PFOA (mg/kg)PFOA (mg/kg)MaterialMaterial

Migration of PFOA from microwave Migration of PFOA from microwave

popcorn bags?popcorn bags?

Temperature of oil from microwave susceptor

heating

0

50

100

150

200

250

0 0.5 1 1.5 2 2.5 3 3.5

Time (min)

Te

mp

era

ture

°C

Migration of PFOA from Migration of PFOA from

microwave popcorn bags?microwave popcorn bags?

NoneNone detected into oildetected into oil

T. H. Begley, et al., 2005, T. H. Begley, et al., 2005, PerfluorochemicalsPerfluorochemicals: Potential sources of : Potential sources of and migration from food packaging. and migration from food packaging. Food Food

Additives and Additives and ContaminatsContaminats, 22 (10) 1023, 22 (10) 1023--1031.1031.

Test for Test for perfluorochemicalperfluorochemical

migration from commercially migration from commercially

produced paperproduced paper

Typical structures of Typical structures of PerfluoroPerfluoro telomer based telomer based

paper coatingspaper coatings

NH4+

POO

O

-OS

O

O N

F

FF

F F

FF

F

F

F

F

F

F

FF

FF

SOO

N

F

F

F

F

F

F

F

F

F

F

F

F

F

FF

F F

S

S

F

FF

HF

FF

F

F

FF

FF

F

FF

F

FF

F

F

F

FF

F F

F

F

F

FF

FF

F

O

O

OO

P

NH4+

F

FF

F

FF

F

F

F

FF

F

F

F

F

F

F

FFF

F F

F

F

F

F

F

F

F

F

F

F

F F

O

P

O

O

O

H2N

OH

OH

AABB

CC

Test conditions for Test conditions for

perfluorochemicalperfluorochemical migrationmigration

•• Food simulating liquids/foods at 100Food simulating liquids/foods at 100°°CC

•• SingleSingle--sided contact with paper sided contact with paper

•• Contact time 15 minutes Contact time 15 minutes

•• LCMS analysis for LCMS analysis for perfluorochemicalperfluorochemical

Typical structures of Typical structures of PerfluoroPerfluoro telomer telomer

based paper coatingsbased paper coatings

NH4+

POO

O

-OS

O

O N

F

FF

F F

FF

F

F

F

F

F

F

FF

FF

SOO

N

F

F

F

F

F

F

F

F

F

F

F

F

F

FF

F F

S

S

F

FF

HF

FF

F

F

FF

FF

F

FF

F

FF

F

F

F

FF

F F

F

F

F

FF

FF

F

O

O

OO

P

NH4+

F

FF

F

FF

F

F

F

FF

F

F

F

F

F

F

FFF

F F

F

F

F

F

F

F

F

F

F

F

F F

O

P

O

O

O

H2N

OH

OH

AABB

CC

Migration results for incidental contact, Migration results for incidental contact,

Coating Coating AA

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

Re

lati

ve

Mig

rati

on

(m

g/k

g)

Wat

erVin

egar

10%

EtO

H20

% E

tOH

25%

EtO

H30

% E

tOH

Butte

r

Oil

Migration results for incidental contact, Migration results for incidental contact,

Coating Coating BB

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Re

lati

ve

mig

rati

on

(m

g/k

g)

Wate

rVin

egar10%

EtO

H20%

EtO

H25%

EtO

H30%

EtO

H

Butte

r

Oil

Migration results for incidental contact, Migration results for incidental contact,

Coating Coating CC, paper produce in 1987, paper produce in 1987

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

0.800R

ela

tiv

e M

igra

tio

n

(mg

/kg

)

Wate

r

Vinegar

10% E

tOH

25% E

tOH

Butt

er

Oil

Potential Problem for Potential Problem for

Exposure Estimates?Exposure Estimates?

Water and oil are not the extremes!Water and oil are not the extremes!

Typical Migration Results From a PolymerTypical Migration Results From a Polymer

Migration of Irganox 1076 from PP at 135Migration of Irganox 1076 from PP at 135°°CC

0

500

1000

1500

2000

2500

3000

3500

4000

4500

µg

/dm

2

Wat

er

Gra

vy (n

o fat)

Bak

e bea

n

Bab

y Food (b

anan

a)

Corn

ed B

eef H

ash

Gra

y (1

0%fa

t)

Chic

ken S

oup

Chic

ken B

roth

Bab

y Food (t

urkey

)B

eef S

tew

Corn

Oil

Migration into EmulsionsMigration into Emulsions

•• Butter = waterButter = water--inin--oil Emulsion (20% / 80%)oil Emulsion (20% / 80%)

•• NonNon--ionic surfactant (ionic surfactant (polyoxyethylenepolyoxyethylenesorbitansorbitan / oil / water)/ oil / water)

•• Ionic surfactant (lecithin / oil / water)Ionic surfactant (lecithin / oil / water)

Migration from paper, 40Migration from paper, 40°°C 1 dayC 1 day

0

0.2

0.4

0.6

0.8

1

1.2

Mig

rati

on

µg

/cm

2

Butter

Chocolate spread

Emulsion -nonionic

Emulsion -ionic

Oil

Oil + ionic (soy)

Oil + nonionic

Migration of Fluorochemical is Migration of Fluorochemical is

Kinetic to food at 40Kinetic to food at 40°°CC

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

Mig

rati

on

µg

/cm

2

Chocolate

1 day

Chocolate

10 day

Butter

40 day, 4°C

Do Do PerfluoroPerfluoro telomer Paper Coatings telomer Paper Coatings

Migrate Under Actual Conditions of Migrate Under Actual Conditions of

Use?Use?

Migration from microwave Migration from microwave

susceptorsusceptor into oilinto oil

Results for migration of fluorotelomer Results for migration of fluorotelomer

from popcorn bagsfrom popcorn bags

2.1 mg/kg 2.1 mg/kg

77µµg/ dmg/ dm22

Concentration in Concentration in

Miglyol Miglyol afterafter 2 min. 2 min.

microwave heating microwave heating

1.4 mg/kg 1.4 mg/kg

4 4 µµg/ dmg/ dm22

Concentration in Concentration in

Popcorn Oil Popcorn Oil beforebefore

HeatingHeating

LCMS analysis of LCMS analysis of PopcornPopcorn for the Migration of for the Migration of

Fluorotelomer from Popcorn bagFluorotelomer from Popcorn bag

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

0 1 2 3 4 5 6 7 8 9 10

Time (min)

LC

MS

Re

sp

on

se

Fat Free Popcorn Control Popcorn

m/z = 921 --

m/z = 1021 --

-- m/z = 1121

Migration of Migration of perfluorotelomerperfluorotelomer into into

microwave popcornmicrowave popcorn

mg/kgmg/kgBrandBrand

2.12.1EE

1.21.2DD

3.83.8CC

0.80.8BB

1.21.2AA

Conclusions of Migration TestsConclusions of Migration Tests

•• The food The food simulantssimulants waterwater and and oiloil are not are not the extremes for these the extremes for these fluorochemicalsfluorochemicals..

•• The soy emulsifier (lecithin, 0.05%) can The soy emulsifier (lecithin, 0.05%) can change oil into a potent solvent for change oil into a potent solvent for migration.migration.

•• Fluorotelomers do migrate to food in the Fluorotelomers do migrate to food in the mg/kg (mg/kg (ppmppm) range.) range.

S

S

F

FF

FF

FF

F

F

FF

FFF

F

FF

FF

F

FF

FF

FFF

FF

F

F F

F

F

O

O

OHO

P

Migration to oil = noneMigration to oil = none

Migration to oil + emulsifier = hugeMigration to oil + emulsifier = huge