Chemicals Listed Effective August 11, 2023 as Known to the State of California to Cause Cancer: Anthracene, 2-Bromopropane, and Dimethyl Hydrogen Phosphite

Effective August 11, 2023, the Office of Environmental Health Hazard Assessment (OEHHA) is adding anthracene (CAS RN 120-12-7), 2-bromopropane (CAS RN 75-26-3), and dimethyl hydrogen phosphite (CAS RN 868-85-9) to the list of chemicals known to the State of California to cause cancer under the Safe Drinking Water and Toxic Enforcement Act of 1986, sections 25249.5 et seq. of the Health and Safety Code (HSC), otherwise known as Proposition 65. The listing of these chemicals is pursuant to the “Labor Code” listing mechanism (HSC section 25249.8(a); Title 27 Cal. Code of Regs. section 25904).

The basis for the listings was described in a public notice published in the June 16, 2023 issue of the California Regulatory Notice Register (Register 2023, No. 24-Z). The title of the notice was “Notice of Intent to List Chemicals by the Labor Code Mechanism: anthracene, 2-bromopropane, and dimethyl hydrogen phosphite.” The publication of the notice initiated a public comment period (June 16, 2023 – July 17, 2023). No comments were received during the comment period.

A complete, updated Proposition 65 chemical list is available on the OEHHA website.

Background on Listing by the Labor Code Mechanism 

Health and Safety Code section 25249.8(a) incorporates California Labor Code section 6382(b)(1) into Proposition 65. The law requires that certain substances identified by the International Agency for Research on Cancer (IARC) be listed as known to cause cancer under Proposition 65. Labor Code section 6382(b)(1) refers to substances identified as human or animal carcinogens by IARC. OEHHA has adopted regulations concerning these listings in Title 27, California Code of Regulations (CCR), section 25904. As the lead agency for the implementation of Proposition 65, OEHHA evaluates whether a chemical’s listing is required.

OEHHA’s Determination 

Anthracene, 2-bromopropane, and dimethyl hydrogen phosphite meet the requirements for listing as known to the state to cause cancer for purposes of Proposition 65 (Title 27, CCR, section 25904(b)(3)).

IARC published on its website a list entitled “Agents Classified by the IARC Monographs, Volumes 1 - 133" (IARC, 2023). IARC concluded that 2-bromopropane is classified in Group 2A (“probably carcinogenic to humans”) and that anthracene and dimethyl hydrogen phosphite are classified in Group 2B (“possibly carcinogenic to humans”). IARC concluded that there is sufficient evidence of carcinogenicity in animals for anthracene, 2-bromopropane, and dimethyl hydrogen phosphite (Cattley et al., 2023).