technologies and alternatives richard holt biac 1
TRANSCRIPT
Technologies and Alternatives
Richard HoltBIAC
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Limitations for any Discussion of AlternativesNumerous alternativesTime constraintsCompetitive considerationsAnti-trust considerationsKnowledge base – proprietary uses and formulations
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Primary Current Transition Path Surfactants
From >6-Carbon to 4-Carbon-based sulfonate chemistryFrom >8-Carbon to <6-Carbon Fluorotelomer chemistry From 8- and 9-Carbon Perfluorocarboxylate
Polymerization Aids (PFOA/PFNA) to certain Mono- and Poly-perfluoroethers or other substances
Surface Modification PolymersFrom >6-Carbon to 4-Carbon-based sulfonate chemistryFrom >8-Carbon to <6-Carbon Fluorotelomer chemistry
Requires cooperation from manufacturers in a wide range of downstream industries, from consumer product manufacturers to defense and aerospace industries
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Potential AlternativesIn Kind: Fluorinated
C6: Fluorotelomer-based six fluorinated carbon functionality compounds
C4: Electrochemical fluorination-based four fluorinated carbon functionality compounds - Perfluorobutane sulfonate (PFBS)
Mono- and poly-fluorinated ether functionality compounds (e.g., CF3 or C2F5 fluoroalkyl polyethers)
Fluorinated oxetanesOther fluorinated polymers
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Potential AlternativesNot-in-kind
Hydrocarbons Propylated naphthalenes or biphenyls Fatty alcohol polyglycol ether sulfate Sulfosuccinate Hydrocarbon surfactants Naphthalene derivatives
Siloxanes and silicone polymers
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Do The Alternatives Work?
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The transition from the current highly effective products to suitable alternatives has been accomplished with the following criteria as guidelines:•Efficacy of use be maintained•Reduced biopersistence•Minimization of customer disruption •Value in use be maintained•Critical societal uses are not compromised•Reduction of the environmental footprint
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Non-Fluorinated AlternativesNon-fluorinated alternatives, such as
different hydrocarbon surfactants and silicone products, have been identified… however, in most cases or at least in larger application areas, other fluorinated compounds are used instead…. non-fluorinated alternatives do not work as well, especially in situations, where extreme low surface tension is needed (Danish EPA, 2006).
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Effectiveness of Newer Alternatives: What are we finding?C-6 and C-4 chemistries adequately meet the criteria for replacement of most current C-8 and higher homologue uses.
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New Chemical Review of Alternatives*US EPA is reviewing substitutes for Long Chain
PFCs as part of its review process for new chemicals under EPA's New Chemical Program
– Ongoing since 2000– Consistent with the approaches to alternatives encouraged under the PFOA Stewardship Program
– Over 100 alternatives of various types have been received and reviewed by EPA
More information at http://epa.gov/oppt/pfoa/pubs/altnewchems.html
* EPA presentation April 19, 2010 (Las Vegas, Nevada USA) and various other industry and trade meetings
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Unique Properties•Lower aqueous surface tension = wetting power
•the power to spread and coat surfaces•Function at very low concentrations
•100 parts per million•Work well in tandem with hydrocarbon and silicone surfactants•Unique function in “dynamic” systems
Synthesis OriginElectrochemical
fluorination (ECF)FluorotelomerFluoro(poly)etherFluorinated
oxetane
Fluorinated Products - Technology
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Electrochemical Fluorination (ECF) Products
F(CF2)nSO2N(R)CH2CH2OH
Perfluoroalkyl sulfonamido ethanol
An Example of New Products based on n=4
Perfluorobutane sulfonyl (PFBS)
Chemistry
C4F9SO2 - R
H(CH2)nSH aliphatic mercaptan
F(CF2)nSO3XF(CF2)nSO2F
PFDS n = 10
PFOS n = 8
PFHxS n = 6
PFBS n = 4
HF, e-
Sulfonyl fluoride
PFBS = C4F9SO3-
Potential degradation product
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Fluorotelomer-based ProductsCF2=CF2 (TFE)
F(CF2)6I
F(CF2)6CH2CH2I
F(CF2)6CH2CH2OH
An Example of New Products based on
n = 6
PhosphateEthoxylate
Betaine
Fluorotelomer Alcohol
Fluorotelomer Iodide
Perfluoroalkyl Iodide
Potential degradation product
PFHxA, perfluorohexanoate: F(CF2)5CO2-
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Serum concentration of PFHxA or PFBS after
single intravenous administration
1
10
100
1,000
10,000
100,000
1,000,000
PFHxA-MalePFHxA-FemalePFBS-MalePFBS-Female
(hr)
(ng/
mL)
PFHxA
PFBS
Pharmacokinetics in Monkey: PFBS and PFHxA
Fluoropolyether (PFPE) SurfactantsPFPE-diol raw material
MW 1500 AMU; Made by photooxidation including tetrafluoroethylene (TFE)
Phosphate ammonium saltCarboxylate ammonium saltEthoxylated diol
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HOCH2-CF2O-(CF2O)m-(CF2CF2O)n-CF2CH2OH
Summary for the AlternativesAlternatives exist for nearly all current usesThere are some uses still for which adequate
replacements have not yet been identifiedAlternatives with a shorter fluorinated alkyl
chain are still environmentally persistent but not bioaccumulative
The C4 sulfonate and the C6 carboxylate have shown different pharmacokinetics (shorter half-life) and lower toxicity than PFOA and PFOS
Non-fluorinated alternatives do not work as well
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Summary for the AlternativesPFOS and PFOA are some of the most
studied chemicals, therefore ...Alternatives will almost always have less
supporting data, however ...Adequate supporting data have been
submitted to obtain regulatory approval, generally subject to requirements to submit additional data to robustly define hazard and exposure profiles.
Good business move for the future! 17