Ref. Ares(2021)6233449 - 13/10/2021
Discussion on PFHxA
Meeting with DG Environment
and DG Grow
3 July 2018
Background and Purpose
• Planned regulatory activities under REACH related to short-chain PFASs
– RMOA on PFHxA recommending SVHC and restriction proposal
– RMOA on PFBS recommends similar approach
– CLH (STOT) for PFBA
– UBA has initiated preparatory work on a restriction proposal for C4-C7 substances
• Concerns related to short-chain PFASs subject to consultation within the MSC
and PBT Expert group
• The FluoroCouncil would like to share its knowledge on PFHxA and views on
possible ways forward
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Introduction to FluoroCouncil and
FluoroTechnology
About the FluoroCouncil
• Represents the world’s leading manufacturers of FluoroTechnology
based on per-and polyfluoroalkyl substances (PFASs)
• FluoroCouncil has a fundamental commitment to product stewardship
and rigorous, science-based regulation, and, as part of its mission,
addresses science and public policy issues related to PFASs
• Member companies:
– Archroma Management LLC
– Arkema France
– Asahi Glass Co., Ltd.
– Daikin Industries, Ltd.
– Solvay Specialty Polymers
– The Chemours Company LLC
– Tyco Fire Products LP (associate member)
– Dynax (associate member)
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FluoroTechnology
Fluorotelomers - Fluoropolymers
Fluorotelomers:
Fluoropolymers: (Fluoroplastics &
Fluorinated polymers and
fluoroelastomers)
surfactants
• “Short” fluorinated side-chains
• High molecular weight polymers
that may be attached to organic
• PTFE, Melt Copolymers,
polymer backbones (polymers)
Thermoset Elastomers
• Fluorinated “backbone”
•
Modify material properties:
•
Material properties: chemical
surface modification & protection,
resistance, thermal stability,
water & oil repellency; soil
resilience (elastomers)
resistance; wetting, leveling &
•
Applications: Breathable
spreading
membranes, Aerospace Materials,
Hydraulic tubing, Chemical
•
Applications: Textiles, Carpets,
Processing , Semiconductor
Paper, Stone & Tile, AFFF, Paints &
Manufacture, Transportation
Coatings
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Key facts on PFHxA
Toxicological Data for PFHxA Demonstrates Low
Human Health Risk
• PFHxA does not exhibit carcinogenicity, mutagenicity, or genotoxicity.
• PFHxA is neither a reproductive nor developmental toxicant and is not an
endocrine disruptor.
• The PFHxA toxicity value (0,32mg/kg/d) derived by ANSES is four orders of
magnitude higher (less stringent) than the perfluorooctanoic acid (PFOA)
toxicity value currently used by the USEPA
→ The margin of safety for potential daily intake of PFHxA from all routes of
exposure in infants is more than 300,000.
→ Application of standard US EPA drinking water health advisory calculation :
2.2 x106 ppt compared to 70 ppt for PFOA ,i.e. 32,000 times higher
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PFHxA Does Not Bioaccumulate and is Rapidly
Eliminated from the Human Body
• PFHxA does not have as high of a binding affinity for proteins as long-chain
PFAAs, as demonstrated by numerous protein binding assays
• Rapidly eliminated from all mammalian bodies
→ Nearly 100% eliminated within the first day after dosing in rodents (Gannon et al 2011)
→ Elimination half-lives of PFHxA between 0.5 to 1.7 hours in rats and 2.4 to 5.3 hours in
monkeys (reviewed in Han 2011)
→ Elimination kinetics for PFHxA analyzed in humans (a cohort of professional ski wax
technicians) : apparent half-life estimated at approximately 28-32 days (Russell 2013)*
•
Occurrence studies involving PFHxA have confirmed that PFHxA typically has a low
frequency of detection or low level of detection. For these reasons:
– PFHxA was not included in the USEPA Unregulated Contaminant Monitoring Rule evaluation
of the Centers for Disease Control and Prevention’s National Health and Nutrition
Examination Survey (NHANES)
*Not designed as a definitive half-life study
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Environmental occurrence is and will most likely
remain low
• C6-based fluorotelomer products have been available on the market since
the 1970’s
– The notion that this chemistry is new is misleading and false
• PFHxA is present due to one of three pathways: as a manufacturing
impurity, as a degradation product or from direct use
• Recent degradation tests on a C6 methacrylate-based fluorinated polymers
show very slow degradation: t1/2 ca. 3,000 years*
• Effective and responsible use of C6-based fluorotelomer products by
employing industry best practice guidance coupled with emission controls –
will help ensure that levels of PFHxA remain low
• To date there are no known definitive published temporal studies that
support the premise that “exposure to PFHxA is increasing everywhere“.
*Publication of this work in preparation
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Multiple Full-Scale Treatment Technologies Available to
Remove PFHxA and Other Short Chain Acids From Water
• Demonstrated full-scale water treatment technologies are available for the
removal of PFHxA to published safe drinking water levels
– Best Removal/Treatment Options Consists of a “Treatment Train”
• 2 or more technologies in series
– Options Include Ion Exchange Resins, Membrane Filtration such as RO,
GAC as well as other options
• Treatment technologies capable of complete removal and destruction of
PFHxA and other related fluorotechnology products are available as well as
in development and will likely evolve to commercial full-scale applications
– Advanced chemical oxidation techniques
– Incineration
– Filtration, Coagulation, RO membranes etc.
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Industry and Market Reliance on C6
Fluorotelomer-based Chemistry
•
The main applications include performance textiles, carpeting, paints and
coatings, high hazard Class B fire fighting foams (AFFF), electronics, food
packaging, as well as building and construction.
The
MIDWOR-LIFE analysis, co-funded by European Union, assessed as
regards textiles:
Fluorine free alternatives only offer a similar level of protection with the singular
property of water repellency.
◼
t
•
Non-fluorinated alternatives may be used in applications requiring limited
performance: water-repellency and water-based stains only, fire fighter training
and extinguishing of some Class B fires
•
Substitution from C8- to C6-based products was the result of years of research, product
redesign and reformulation as well as significant customer requalifications, work with
governmental agencies, and significant investments.
C6 fluorotelomer-based substances are key in supporting and
completing the transition from C8 fluorotelomers globally
Continued efforts in the field of Best Practices
• The FluoroCouncil works with downstream sectors to develop Best
Management Practices along the life cycle of products
– BAT/BEP Textile : For Textile Mills and Finishers, as well as for
Packagers, Brands and Retailers
•
Safety Data Sheet (SDS) and Technical Data Sheet (TDS) advice
•
Material reuse/recycle and waste disposal
•
Emissions’ minimisation
– BEP Fire fighting foams :
• Covers use conditions, training, containment and disposal
• The FluoroCouncil and industry recommends to avoid the use of AFFF for
training purposes
• Transition to short-chain fluoro-chemicals and responsible use of these will
greatly and immediately diminish the emissions of long-chain PFAS
PFHxA Assessment of Risk Considerations
• PFHxA exhibits low overall toxicity
• Soil biodegradation studies on C6 fluorotelomer side-chain
polymers provide a degradation half life of thousands of years
• Large Margins of Safety using the published derived Reference
Dose
– Several Orders of Magnitude Margins in both human exposure and via
drinking water
• Current use patterns, trends, emission controls and best
practices will help keep both presence and exposure low
The data do not support the
listing of PFHxA as SVHC
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Options going forward
• We do not believe the data on PFHxA provide basis for
SVHC
identification based on an equivalent level of concern to PBT/vPvB
• Data are available to quantify the risk, which questions the use of the
precautionary principle
• REACH Restriction process requires in-depth risk and socio-economic
assessment
• Continuous efforts to minimise emissions to the lowest levels
technically feasible via application of BAT/BEPs through the entire
value chain
• US EPA PFOA Stewardship Programme, a successful example of
authorities-industry cooperation
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Thank you
Human monitoring data
Sample
LOD
Country / Study
Size
(ng/mL)
FOD (%)
Citation
U.S. / C8 Health Study
67,000
<0.5
53%
Frisbee (2009)
New Zealand / POP Study
747
<0.5
0%
New Zealand Ministry of
Health (2013)
U.S. / American Red Cross
2,294
<0.02 – 0.1
6%
Olsen (2017)
South Korea
1,874
<0.11
0%
Lee (2017)
Canada / Health Measures
1,524
<0.1
2%
Health Canada (2013)
Study
Japan / Exposure to Chemical
326
<0.1
0%
Japan Ministry of the
Compounds
Environment (2016)
China / General Population
202
<0.01
53%
Li (2017)
Study of Three Provinces
Norway / A-Team Study
61
<0.045
0%
Poothong (2017)
* Second analysis of 1,180 samples by another laboratory: PFHxA detected in none of the samples
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Degradation Test Data
Report
Status or
Test name
Method
Test Item
Conclusion
number
deadline
Inherent
The results clearly show that up to day 55
Biodegradability
Perfluoro
only the 6-2 FtOH that remained in the test
OECD302B
Zahn-Wellens-
polymer
AZW15653 Finalized
solution long enough, was transformed to
(adapted)
Test / EMPA
dispersion
PFHxA. No degradation of the polymer was
Test
determined.
The test item has to be considered to be very
Aerobic
Perfluoro
OECD307
slowly transformed by aerobic biological
Transformation
polymer
ASB15653 Finalized
(extended)
processes in soil (t1/2 > 2900 years in all four
in Soil
dispersion
soils tested)
Anaerobic
Perfluoro
OECD307
Ongoing
Interim results show longer half-life time than
Transformation
polymer
(extended)
Sept-2018
in aerobic conditions
in Soil
dispersion
•
These recent degradation tests on a C6 methacrylate-based fluorinated polymers show
very slow degradation: t1/2 ca. 3,000 years
➢ Test conclusion: sum of all potential degradation products less than 0.04% of 6-2 FTOH
equivalents in all four soils
➢ Transformation rates would be even slower in soils with less aerobic biological activity.
Studies under anaerobic conditions are underway.
➢ The test protocols were conducted along OECD testing method guidelines and were
approved the US EPA.
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