Chemical Listed Effective May 7, 2004 as known to the State of California to Cause Cancer: Nickel Compounds

The Office of Environmental Health Hazard Assessment (OEHHA) of the California Environmental Protection Agency is adding nickel compounds to the list of chemicals known to the state to cause cancer for purposes of the Safe Drinking Water and Toxic Enforcement Act of 1986 (Health and Safety Code section 25249.5, Proposition 65). The listing of nickel compounds is effective May 7, 2004.

“Nickel and certain nickel compounds” were added to the Proposition 65 list October 1, 1989 by reference to Labor Code Sections 6382(b)(1) and (d) as required by Health and Safety Code Section 25249.8(a). The law requires that certain substances identified by the International Agency for Research on Cancer (IARC) or the National Toxicology Program (NTP), as described in Labor Code Section 6382(b)(1) and Labor Code Section 6382(d) be included on the Proposition 65 list. IARC and NTP have updated their prior listing, from “nickel and certain nickel compounds” to “metallic nickel” and “nickel compounds.” OEHHA is therefore updating the Proposition 65 list to conform to the language in the IARC classifications and the new listing designations in NTP's Report on Carcinogens, as required by law.

The basis for the update of “nickel compounds” on the Proposition 65 list was described in OEHHA's Request for Comment on Proposed Listing of Nickel Compounds as Known to Cause Cancer published in the June 6, 2003, issue of the California Regulatory Notice Register (Register 2003, No. 23-Z). Briefly, both IARC and NTP have identified nickel compounds, as a group, as carcinogens. Specifically, IARC issued the monograph Chromium, Nickel and Welding (Volume 49) in 1990 in its series IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, and classified “nickel compounds” as “carcinogenic to humans (Group 1)” and NTP released its Tenth Report on Carcinogens in 2002 in which it included “nickel compounds” on the list of substances “known to be human carcinogens.”

For the purposes of clarification, OEHHA notes that nickel alloys are distinct from nickel compounds, and are not included in the Proposition 65 listing of nickel compounds . A nickel compound is a substance consisting of nickel and one or more other elements combined in definite proportions (e.g., by ionic or covalent bonds). A nickel alloy is a mixture of nickel with one or more other elements, typically produced by mixing molten nickel with other substances. The atoms in an alloy are not covalently or ionically bonded in fixed ratios.

As indicated in Title 22 of the California Code of Regulations Section 12707(b)(5), for purposes of Proposition 65, nickel and nickel compounds present no significant risk of cancer by the route of ingestion.

A complete, updated Proposition 65 list is published elsewhere in this issue of the California Regulatory Notice Register.