On September 13, the U.S. Environmental Protection Agency (EPA) published a notice proposing to remove 12 per- and polyfluoroalkyl substances (PFAS) from its list of inert ingredients approved for use in regulated pesticide products. The 12 PFAS are listed below. According to EPA’s review, none of the 12 PFAS are being used as inert ingredients in any registered pesticide products; however, removing chemicals from EPA’s list of approved inert ingredients ensures that any future proposed use of these PFAS as inert ingredients would require substantiation with data (including, among other things, studies evaluating potential carcinogenicity, genotoxicity, adverse reproductive effects) and approval by EPA.
EPA has also recently released new data from its ongoing evaluation of potential PFAS leaching into liquid pesticide products from fluorinated high-density polyethylene (HDPE) product containers. EPA released an initial set of data in March 2021 that preliminarily concluded that PFAS could leach into pesticide products due to a chemical reaction during the product container fluorination process. EPA’s new study data shows that PFAS present in fluorinated HDPE pesticide product container walls can readily leach into the formulated liquid products over time. This leaching occurs in higher total amounts for formulated organic solvents, such as methanol, as opposed to water-based products; but for both methanol- and water-based solvents, EPA’s data indicates gradual PFAS leaching into the product over time, with higher leaching over longer periods. EPA’s study did not evaluate whether fluorinated HDPE containers treated by different fluorination methods and technologies would cause PFAS to be present in the containers.
Based on these recent studies, EPA has reiterated (see number 4 in the “PFAS in Pesticides Questions”) that per Section 6(a)(2) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), if a pesticide registrant discovers any level of PFAS in its pesticide products, it should report that information to the agency within 30 days as a detection of “additional factual information regarding unreasonable adverse effects,” such as “metabolites, degradates, contaminates, [or] impurities,” per EPA’s FIFRA regulations (40 C.F.R. § 159.155(a)(5)). This is because EPA considers any level of PFAS to be toxicologically significant. EPA has also reiterated to pesticide registrants that if they discover PFAS leaching from product containers, the registrant should consult with EPA about the identification and use of alternative packaging moving forward.
Appendix: 12 PFAS Chemicals EPA Is Proposing to Remove From Approved Inert Ingredient List
- 2-Chloro-1,1,1,2-tetrafluoroethane (CAS Reg. No. 2837-89-0)
- α-(Cyclohexylmethyl)-ω-hydropoly(difluoromethylene) (CAS Reg. No. 65530-85-0)
- Dichlorotetrafluoroethane (CAS Reg. No. 1320-37-2)
- Ethane, 1,1,1,2,2-pentafluoro- (CAS Reg. No. 354-33-6)
- Hexafluoropropene, polymer with tetrafluoroethylene (CAS Reg. No. 25067-11-2)
- Montmorillonite-type clay treated with polytetrafluoroethylene (No CAS Reg. No.)
- Poly(difluoromethylene), α-chloro-ω-(1-chloro-1-fluoroethyl) (CAS Reg. No. 131324-06-6)
- Poly(difluoromethylene), α-chloro-ω-(2,2-dichloro-1,1,2-trifluoroethyl)- (CAS Reg. No. 79070-11-4)
- Poly(difluoromethylene), α-(2,2-dichloro-2-fluoroethyl)-, ω-hydro- (CAS No. 163440-89-9)
- Poly(difluoromethylene), α-fluoro-ω-[2-[(2-methyl-1-oxo-2- propenyl)oxy]ethyl]- (CAS Reg. No. 65530-66-7)
- Poly(oxy-1,2-ethanediyl), α-hydro-ω-hydroxy-, ether with α-fluoro-ω-(2-hydroxyethyl)poly(difluoromethylene) (1:1) (CAS Reg. No. 65545-80-4)
- Propane, 1,1,1,2,3,3,3-heptafluoro- (CAS Reg. No. 431-89-0)