© Kelly Franklin, Chemical Watch News & Insight
California's Office of Environmental Health Hazard Assessment (OEHHA) has said it intends to add three PFAS as reproductive toxicants under Proposition 65, after finding the substances qualify for listing under the scheme's ‘authoritative bodies’ mechanism.
If the listings are finalised, companies would be required to provide warnings for significant exposures to perfluorobutanoic acid (PFBA), perfluorodecanoic acid (PFDA), perfluorohexanoic acid (PFHxA) and their related salts.
OEHHA announced the plan on 30 October, saying it intended to list the substances under Prop 65 based on toxicological assessments by the US EPA's Integrated Risk Information System (IRIS), which found they are likely to cause reproductive or developmental effects in humans.
PFBA and PFHxA are both used in the manufacture of photographic film and as substitutes for long-chain perfluoroalkyl carboxylic acids (LC-PFCAs) in consumer products, according to IRIS assessments completed in 2022 and 2023. Both substances are breakdown products of other PFAS used in stain-resistant fabrics, paper food packaging and carpets.
PFDA, meanwhile, has been used in consumer products and industrial applications, including stain- and grease-proof coatings for food packaging, furniture, upholstery and carpet. It has also been detected in outdoor textiles, gloves, ski wax and leather, according to IRIS, which completed a toxicological review of the compound in 2024.
While the EPA has sought to minimise the value of IRIS assessments under the current administration, the programme’s findings can still support a Prop 65 listing under the law's ‘authoritative bodies’ mechanism, if OEHHA determines they are are based on evidence that meets specified sufficiency criteria.
Growing number of PFAS on Prop 65 list
The addition of the three substances would double the number of widely recognised PFAS on the Prop 65 list, joining PFOA, PFOS and PFNA and their salts.
The Prop 65 list includes two other substances that may qualify as PFAS under some broader definitions of the substance class: para-chlorobenzotrifluoride (PCBTF) and acifluorfen sodium. Tetrafluoroethylene (TFE), which is used to make polytetrafluoroethylene (PTFE), known by the brand name Teflon, is also listed under the state’s right-to-know scheme.
In addition, OEHHA identified PFBS and GenX as candidates for addition to Prop 65 in 2022, and gathered information in 2021 on the potential reprotoxic properties of PFHxS and PFUnDA.
Comments on the planned listings for PFBA, PFDA and PFHxA are due by 30 November.