On December 23, 2025, the agency implementing California’s Proposition 65, the Office of Environmental Health Hazard Assessment (OEHHA), published an Information Letter on exposures to vinyl acetate from consumer products. The Letter clarifies that the warning requirement applies only to the monomer vinyl acetate and provides guidance on testing.  

By way of brief background, vinyl acetate was added to the Prop 65 List as a carcinogen on January 3, 2025. In its Evidence on the Carcinogenicity of Vinyl Acetate, OEHHA commented that vinyl acetate is approved as a modifier for food starch, as well as that “[v]inyl acetate-based polymers are used in adhesives and glues, paints, paper coatings, textile and leather finishing, plastics and resins, inks and lacquers, heat sealing films, pesticides, and cosmetics” and that vinyl acetate-based polymers have been approved as food additives for use in chewing gum bases.

With the warning requirement for vinyl acetate taking effect on January 3, 2026, OEHHA’s Information Letter clarifies that the warning requirement applies to only the monomer vinyl acetate. As stated in the Letter, vinyl acetate “is mainly used in the production of polymers and copolymers” that were not added to the Prop 65 List, and that the monomer vinyl acetate, CAS No. 108-05-4, “is uncommon in consumer products, although residual unreacted monomer may be present in some products made with vinyl acetate polymers and copolymers.”

Accordingly, OEHHA’s Information Letter cautions that “[t]he fact that a consumer product contains a vinyl acetate-based polymer or copolymer is not, by itself, factual information sufficient to establish a potential exposure to vinyl acetate.” Accordingly, to determine whether a warning is required for an exposure to vinyl acetate, “[a] test should not . . . reflect the amount of vinyl acetate obtained from dissolving vinyl acetate-containing polymers in a manner which would not otherwise occur during the foreseeable use, purchase, storage, maintenance, or repair of the product.”   

OEHHA’s December 23 Information Letter can be found here.