New Carcinogen Listing for Vinyl Acetate

As of January 3, 2025, vinyl acetate has been officially added to California’s Proposition 65 list as a carcinogen. This decision follows the Carcinogen Identification Committee’s (CIC) assessment that the chemical poses a significant cancer risk based on scientifically valid testing. The warning requirement for significant exposures to vinyl acetate will take effect on January 3, 2026.

Proposition 65 Carcinogen Listing Process

The listing of vinyl acetate as a carcinogen was made through the "State’s Qualified Experts" mechanism, where the CIC determined through expert review that the chemical has been clearly shown to cause cancer. This conclusion was reached after reviewing a body of scientific evidence and is in line with California’s Proposition 65 regulations.

On December 19, 2024, the CIC held a meeting to discuss the evidence supporting the carcinogenicity of vinyl acetate. After reviewing the findings, the committee voted 11-0 in favor of listing the chemical. Public comments were also taken into account before the final decision.

Public Participation and Data Review

Ahead of the CIC meeting, OEHHA (Office of Environmental Health Hazard Assessment) issued a request for relevant data on vinyl acetate's carcinogenicity, which was open from July 7, 2023, to September 18, 2023. Following the data collection, OEHHA published a hazard identification document and held a public comment period from October 4, 2024, to November 18, 2024.

Other CIC Actions: HFPO and New Appointments

In addition to the vinyl acetate listing, the CIC also voted 11-0 to add 2,2,3-trifluoro-3-(trifluoromethyl)oxirane (known as hexafluoropropylene oxide or HFPO) to a separate list of chemicals requiring additional testing due to inadequate data.

Moreover, the CIC welcomed two new members appointed by the Governor in 2024: Dr. Ludmil Alexandrov, Associate Professor at UC San Diego, and Dr. Dean Felsher, Professor at Stanford University School of Medicine. These appointments were noted as part of the committee’s ongoing efforts to ensure diverse expertise in reviewing chemical safety.

Conclusion: Implications for Businesses and Consumers

With the inclusion of vinyl acetate on the Proposition 65 list, businesses will need to assess exposure levels and provide appropriate warnings to consumers starting January 3, 2026. The decision underscores California's commitment to protecting public health by addressing chemicals with potential cancer risks.