Document mpYDb8NGqGxZJManqEZ2kB4G0
NFPA WSC&E
2-5 June 2008 Las Vegas, Nevada
Dr. Stephen Korzeniowski E. I. duPont de Nemours & Co., Inc.
Copyright DuPont 2008
"Safety & Protection - Be Sure"
The miracles o f science US00007979
Reference Forums
Fluorinated surfactants in AFFF products discussed and debated in numerous journal articles and highlighted in each of the three Reebok Meetings:
- Meeting 1, August 2002
Focused on general information about FFFC, TRP, Testing Approaches and Plans in Toxicology and EF&E
Presented initial physical property and Environmental Effects data
- Meeting 2, December 2004, "Foam Under Fire!"
AFFF Surfactant Beliefs - Fact or Fiction Toxicology and Ecotoxicology Updates and Plans
- Meeting 3, September 2007
Key Questions, Comparative Chemistry, Sources of PFCAs Trends, Toxicology, Biopersistence and Bioaccumulation EF&E and Industry Efforts
"Safety & Protection - Be Sure"
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Central Questions
Where are PFOA and higher homologues (PFCAs) and related polyfluorinated materials found in the environment?
Where did/do the PFCAs come from? Are consumers exposed? Are there any hazards? What is being done? Emission Reduction Efforts? How will we know exposure is getting lower? Are my products safe?
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Highlighted Results
PFHxA, C6 acid, toxicology in rats
- NOAEL for subchronic toxicity is 20 mg/kg/day; No effects on reproductive parameters, NOAEL = 500 mg/kg/day; NOAEL in development toxicity test is 100 mg/kg/day. Neither a selective developmental nor reproductive toxicant
- NOAEL for Neurotoxicological behavior was 500 mg/kg/day - Not Genotoxic
Biopersistence screening in rats
- PFHxA, 6-2 FTS, and Fluorotelomer-based AFFF surfactants showed very low uptake and rapid clearance overall and versus PFOS
Environmental Fate and Effects Studies on 6-2 FTS
- Rainbow Trout Early Life Stage (ELS) 90-day Study gave NOEC values of low concern for chronic toxicity
- Rainbow Trout Bioconcentration and Bioaccumulation Study showed rapid depuration and gave BCF/BAF values of low concern (BCF <50)
6-2 FTS = 6-2 Fluorotelomer sulfonate; PFHxA = Perfluorohexanoic Acid
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Fluorotelomer and ECF Products : Different Chemistry
Fluorotelomers (Fluorotelomers)
ECF (Electrochemical Fluorination)
C F 2= C F 2
(T F E )
I
F(CF2)J
Perfluoroalkyl Iodide
n = 6,8,10,12, even ir
F(CF2)n- u -- I Fluorotelomer Iodide
-- F(CF2)nCH2CH2S 03X: FT Sulfonate -- AFFF Surfactants
F(CF2)n
|
,OH
Fluorotelomer Alcohol
H(CH2)nSH
F(CF2)nS 0 2F ----------- F(CF2)n X
PFOS n = 8; PFHXS n = 6 PFBS n = 4
F(CF2)nS 0 2N(R)CH2CH20H
Perfluoroalkyl sulfonamido ethanol
ir
Sales Products
Sales Products
Even number, straight chains, No Branching Polymers n> 8 ; Surfactants n=6 primarily
ECF produced materials have up to 30% branched isomers at the fluorinated chain end and contain odd and even carbon chain lengths
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PFOA = Perfluorooctanoic Acid = C7F15C 02H = CF3(CF2)nC 02H, where n =6
PFCAs = Perfluorocarboxylic Acids, where n = 3-12
Precursors - can transform to PFCAs by abiotic and/or biotic means
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What is Perfluorooctanoic Acid (PFOA)?
PFOA is a surfactant used as a processing aid to produce fluoropolymer high-performance materials
PFOA and other PFCAs are unintended byproducts of other fluorochemical manufacturing and the previous manufacture of POSF-based products
PFOA and other PFCAs are not used to make a different family of compounds, called fluorotelomers.
- However, they are found at very low trace levels in some fluorotelomer products as a byproduct of their synthesis and as a result of residuals/precursors breaking down to PFCAs
PFOS and its derivatives are not used to make fluorotelomerbased products and are not formed during manufacture and processing
Other PFCAs = Other Perfluorocarboxylic Acid chain lengths such as C8F17C 02H, also called C9 and PFNA
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Sources of Periluorocarboxylie Acids (PFCAs) in the Environment : A COMPLETE Picture
Direct Sources
APFO
APFN
1950's - Present 1970's - Present
PFCA Manufacture
1950's - Present
Fluoropolymer Manufacture 1950's - Present
Fluoropolymer Dispersions 1950's - Present
AFFF Products 1965- 1974
Consumer & Industrial Products
1950's - Present
Indirect Sources
lomer-Based P 1970's - Presen OSF-Based Produc PFCA Impurities
Prevedouros, et al. Environ. Sci. Techno!. 2006 40(1), 32.
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Sources, Fate & Transport Summary
The sources of PFCAs:
Largest historical sources = direct emissions Small historical sources = indirect emissions (fluorotelomers, fluorotelomer-based AFFF, POSF derivatives, residuals, degradation, etc.)
How PFCAs move in the environment:
Multiple mechanisms in air and water result in long-range transport of PFCAs Surface waters are the environmental sink compartment for PFCAs
We believe we understand how to minimize future exposure:
Global action is needed by all manufacturers and users Significant PFCA emission reductions have already occurred US EPA 2010/15 Stewardship Program - commitment to dramatically reduce future manufacturing emissions and product content
Prevedouros, etal. Environ. Sci. Technol. 2006, 40, 32. Armitage, etal. Environ. Sci. Technol. 2006, 40, 6969 Wania, F., Environ. Sci. Technol. 2007, 41, 4529
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Global Fluorotelomer Industry Manufacturing Volumes and PFOA Blood Levels over Time
.QQ. CDC Data
U) aa>>>
published in 2007 for
NHANES study
re
E
confirms trend in US
(0 re
Q_ TOO3 00
o<
LL
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1974 1985 1989 1990 1999 2000 2001 2004
Year
US data from Olsen et al, Environmental Health Perspectives, Feb 2005; 2005 3M 8(e) filing AR 226-3575/3576 - this mean data point for PFOA is 3.0 ppb for 2004 sampling:
German data from German Federal Environmental Agency UBA report 2004.
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Trend Data
Human Data
- Statistical correlations observed between PFOA and PFOS in human blood - Results do not correlate with fluoropolymer or fluorotelomer historic production
and are inconsistent with biodegradation of fluorotelomer products
Arctic Wildlife
- Limited data suggest decreasing concentrations in Arctic biota of PFOS and PFCAs over the past few years (Butt et al.; Kannan et al.; Tomy et al.)
- PFOA and PFCAs < 8 have negligible bioaccumulation potential in wildlife - Water is proposed to be an important exposure medium - No statistical correlation between PFCAs and any fluorotelomer-based substance
Research Needs
- Additional longitudinal studies of human blood - More spatially and temporally integrated monitoring data
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Fluorotelomers Perfluorohexanoic Acid, Sodium Salt AFFF Surfactants
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Fluorotelomer-based Raw Materials & Products
More than 125 DuPont fluorotelomer-based raw materials and products have been studied:
Test substances are commercial products as they are made and sold
Extensive repeated-dose studies have been completed
- Oral, dermal, inhalation; reproduction, developmental
Toxicity testing has been conducted over the past 30+ years
Fluorotelomer-based products are not generally regarded as hazardous chemicals:
- As a class of compounds, Fluorotelomer products are not genotoxins i.e. not mutagenic materials
- Fluorotelomer products are not viewed as significant environmental toxins
- Fluorotelomer products that have been tested are neither selective developmental nor selective reproductive toxins
- Fluorotelomer products must be used as directed on their respective MSDS
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NaPFHxA* Toxicity Data
Subchronic toxicity study in rats - Crl:CD(SD) Rats (male and female) dosed with either 0, 20, 100, or 500 mg/kg/day via gavage for 90-days - NOAEL for Subchronic Toxicity was 20 mg/kg/day
Reproductive toxicity study in rats - No effects observed on reproductive parameters. Not a selective reproductive toxicant - NOAEL for Reproductive Toxicity was 500 mg/kg/day
Neurobehavioral toxicity study in rats - No effects seen on neurobehavioral parameters - NOAEL for Neurobehavioral Toxicity was 500 mg/kg/day
*Perfluorohexanoic Acid, C6 acid sodium salt
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NaPFHxA Toxicity Data (Cont.)
Developmental Toxicity Study in Rats
- Crl:CD(SD) Rats (time-mated female) Dose groups: 0, 20, 100, or 500 mg/kg/day via gavage during pregnancy
- NOAEL = 100 mg/kg/day. Not a selective developmental toxicant
Genotoxicity Studies (in vitro)
- No evidence of mutations in the Bacterial Reverse Mutation Assay (OECD 471)
- No evidence of chromosome aberrations in human lymphocytes (OECD 473) Conclusion: Not genotoxic
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Forafac 1157 AFFF Surfactant Toxicity
Test Description
Results
Comment
28-day Subchronic Oral Toxicity in Rats
De1 '
NOEL for M/F rats is Doses were 0, 10, 40, 200,
200 mg/kg/day
and 1000 mg/kg/day.
No mortality seen
NOAEL 1000 mg/kg/day
F___i selective
< m ~ ` ant
B ioconcentration in
5 ug/L, BCF = <5.1
Whole fish test
Carp, Cyprinus c a r p io ,
50 ug/L, BCF = <51 Very low bioaccumulation
via OECD 305
potential
By all criteria, n o t
bioaccumulative
Ecotoxicity: low-moderate toxicity in acute fish, invertebrates, and bacterial toxicity tests. Conclusion: of low concern
Forafac 1157 backbone is F(CF2CF2)nCH2CH2S 0 2Y, where n = 3 predominantly , and Y are various organic functional groups or appendages
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Forafac 1157 Developmental Toxicity Study (in Rats)
Results
- Maternal toxicity No Observed Effect Level (NOEL) is 150 mg/kg/day based on "body weight gain reduction" at 1000 mg/kg/day
-F etal developmental toxicity NOEL is 1000 mg/kg/day, the highest dose level tested
Conclusion
-Forafac 1157 is not a developmental toxin
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Mean |jM Equivalents
Forafac 1157 AFFF Surfactant Biouptake and Clearance in Rats: Biopersistence Screen
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AUCINF/Dose
Internal Dose Comparison using Blood AUCINF/Dose (normalized)
600000 n
500000 400000 300000 200000
PFOS PFHxA, 6-2 FTS, and both AFFF FS
Behavior is very different in Biopersistence Screen Test
100000
0
PFOS
PFOA
PFHxA
6-2FTS
Test substance
AF3FS 1 AF3FS2 (F1157) (F 1157N)
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Biopersistence Screen Summary
Fluorine residues can be used to screen test substances for differences in bio-uptake and clearance
Absorption and distribution is evident
- AUCINF provides relative integrated measure of absorbed dose
Relative ranking for blood AUCINF/Dose is
PFOS PFOA > 6-2FTS * PFHxA > F 1157N F 1157
Elimination is evident based on declining concentrations in blood and tissues
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Inherent Biodegradation in Sludge of Forafac 1157 AFFF Fluorosurfactant
OECD 302B - Modified Zahn-Wellens/EMPA test
Main Study Conclusions
- No biodegradation products were observed - No fluorinated species were observed in the gaseous effluent - No additional fluoride was produced (No C-F degradation)
Levels measured were at background and did not change - Test substance was not toxic to the microorganisms and the
system remained aerobic
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Aerobic Biodegradation of 6-2 Fluorotelomer Sulfonate Study Rational and Objectives
Reported that 6-2 FT Sulfonate [F(CF2)6CH2CH2S03X] may be converted to 6-2 FTOH [F(CF2)6CH2CH2OH] and 6-2 FTA [F(CF2)6CH2COOH] (> 15%) and small percentage of PFHxA [F(CF2)5C 0 0H ] (< 4%) in activated sludge when sulfate was depleted (an artificial condition that rarely exists in the environment).
- Erin Marchington et al., 2007 SETAC NA meeting poster
The experimental systems using bacterial culture and activated sludge can readily degrade 6-2 FTOH and 8-2 FTOH and thus serve as positive controls
- Wang et al., ES&T, 2005 and unpublished data.
The present study investigates whether or not 6-2 FT Sulfonate is biodegradable and can be converted to PFHxA under aerobic conditions.
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Study Background : What do we know? What do we want to know?
Known biodegradation pathway for
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No discernible increase of Fluoride (F ), indicative of degradation, in activated sludge and mixed bacterial culture 28 - 60 days after incubation of 6-2 FTS
0 5 10 15 20 25
Days after the initiation
82 FTOH Control
30
0 10 20
30 40 50 60 70
Days after the initiation
62 FTOH Control
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Results and Conclusions
No PFHxA or other metabolites indicative of biodegradation were observed above background level in any samples from activated sludge or bacterial culture.
* 62 FTS was not biodegraded in activated sludge under the aerobic study conditions.
Potential transformation products of 2 mg L~1 6-2 FTS_______
6-2 FTOH 6-2 FTA 6-2 FTUA 5-3 Acid PFHxA
LOD (pg L-1)
Activated sludge (Day 0 - 28)
10 1.6 0.16 0.54 0.32
Mixed bacterial culture With sulfate (Day 0 60)
Mixed bacterial culture W ithout sulfate (Day 0 60)
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Environmental Fate & Effects: Key Results
Rainbow Trout 90-day Early Life-stage Study (ELS) on F1176* - Regulatory guideline study (USEPA 850.1400, OECD 210) conducted under GLP - Exposure concentrations (mean measured):
Control (well water), 0.857, 1.66, 2.62, 4.85, 8.70 mg/L
- No Observed Effect Concentrations
NOEC (first day of hatching, first day of swimup) = 2.62 mg/L NOEC (egg hatching) = 4.85 mg/L NOEC (larval survival and abnormalities at thinning, test end; last day of hatching;
length and dry weight (i.e., growth) at test end) = 8.7 mg/L (highest test concentration)
- These NOEC values are much higher (less concern) than typical values used to screen for chronic toxicity, e.g., NOEC < 0.1 mg/L (Canadian DSL)
*Forafac 1176 = 6-2 FTS, Potassium Salt
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Environmental Fate & Effects: Key Results
Rainbow Trout Bioconcentration and Bioaccumulation Study on Forafac 1176 (Preliminary unaudited analysis)
- Elimination of compound appears relatively rapid (95% within 28 days) once exposure is terminated
- BCF/BAF values suggest low concern for bioaccumulation either from water or diet (e.g., CA DSL, EU criteria BCF > 2000, USEPA criterion > 1000)
Steady state BCF <50; Steady state BAF <2
* Not bioaccumulative according to published regulatory criteria
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Copyright DuPont 2008
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EPA 2010/2015 PFOA Stewardship Program
Participation in the stewardship program requires voluntary corporate commitment to two goals:
1) To commit to achieve, no later than 2010, a 95% reduction, measured from a year 2000 baseline, in both:
- facility emissions to all media of PFOA, precursor chemicals that can break down to PFOA, and related higher homologue chemicals, and
- product content levels of PFOA, precursor chemicals that can break down to PFOA, and related higher homologue chemicals.
2) To commit to working toward the elimination of PFOA, PFOA precursors, and related higher homologue chemicals from emissions and products by five years thereafter, or no later than 2015.
Results from 1st year reported results under VSP indicate significant reductions in both product content and plant emissions
Asahi Glass, Arkema, Ciba Specialty Chemicals, Clariant, Daikin, DuPont, Solvay-Solexis, 3M
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Overall Summary Points
Risk perception regarding PFCs requires a more sophisticated knowledge base and a more refined set of risk communications tools
- Not all fluorochemicals are the same
Rely on suppliers that are willing to work toward defining riskbased safe use and exposure levels. Safe is safe. Period.
The industry needs to consider ways to take action to address the confusion and misleading claims in the marketplace regarding safety and product stewardship
Fluorotelomer-based products are safe for their intended uses and offer significant and unique benefits to society
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Contact Information Steve Korzeniowski Tel : 302.695.8672 Email : stephen.h.korzeniowski@usa.dupont.com
Copyright DuPont 2008
"Safety & Protection - Be Sure"
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