California adds three substances to Proposition 65 list


Nov. 17, 2023

The California Office of Environmental Health Hazard Assessment has added coal-tar pitch, fluoro-edenite fibrous amphibole, and silicon carbide whiskers to the Proposition 65 list.

Regulatory background

Finalized listing

  • On November 17, 2023, the OEHHA announced that it was officially adding the three substances to the Proposition 65 list. The office officially determined that the substances had met the requirements for listing as known to the state to cause cancer for the purposes of Proposition 65.
  • The decision stems back to several monographs that IARC released in 2012 and 2017. In Monograph 100F, IARC determined that coal-tar pitch is a Group 1 carcinogen, and in Monograph 111, determined that fluoro-edenite fibrous amphiboles are Group 1 carcinogens and silicon carbide whiskers are Group 2A carcinogens. Group 1 carcinogens are considered “carcinogenic to humans” under IARC classifications, whereas Group 2A carcinogens are considered “probably carcinogenic to humans” under the same classification structure. The OEHHA determined that based on the IARC classification, there was sufficient evidence of cancer in humans and animals to list coal-tar pitch and fluoro-edenite fibrous amphiboles, and sufficient evidence of cancer in animals to list silicon carbide whiskers.

Next steps

  • The OEHHA will require warning labels on the substances (or products that contain them that provide enough exposure to the substances) within a year of the listing officially becoming active. In addition, the OEHHA will likely release safe harbor warning language which will help provide businesses with the specific warnings that will meet California regulations.

Featuring previous research by Walker Livingston.

To contact the author of this analysis, please email Walker Livingston.
To contact the editor of this analysis, please email Scott Stephens.

Key Documents and Dates


Get an insider’s view on regulatory movements.

Sign up for AgencyIQ’s newsletters to receive exclusive regulatory updates and analysis impacting the life sciences or chemical industry.

Copy link
Powered by Social Snap