California Proposition 65

California voters approved Proposition 65 in 1986, creating the Safe Drinking Water and Toxic Enforcement Act. Originally presented to voters as a way to prevent contamination of drinking water by a few substances “known” to cause cancer or birth defects, Proposition 65 is now widely criticized for requiring meaningless warnings in parking lots, hotel lobbies and restaurant entrances, as well as on airport walls and consumer product packaging.

These “warnings” are required by Proposition 65 even when there is no actual risk of harm to anyone. In fact, Proposition 65 requires warnings at exposure levels as much as 1,000 times lower than the levels proven to have no adverse effect. Proposition 65 is unique to California. No other government, state, federal or foreign, requires warning people about substances at safe levels. Even a business that is perfectly safe and complies with all other applicable laws, such as sanitation and food safety requirements, may be in violation of Proposition 65.

Proposition 65 requires the governor to keep a list of all substances “known” to cause cancer or reproductive toxicity. The governor has delegated that responsibility to the Office of Environmental Health Hazard Assessment (OEHHA), a part of the California Environmental Protection Agency (Cal-EPA). OEHHA determines which substances are “known to cause cancer,” and passes regulations interpreting Proposition 65’s requirements. The regulations are available on ine from the Office of Administrative Law, as Title 22, Division 2, Part 2, Subdivision 1, Chapter 3 of the California Code of Regulations. (They are called “Social Security Regulations” on the OAL website

This is a relic of the time when Proposition 65 was first enacted. OEHHA was part of the Department of Health and Human Services under Governor Wilson.) OEHHA’s website,, also contains a link to the regulations, and provides general information about Proposition 65, including the complete Proposition 65 list of more than 750 substances. Some, such as hexavalent chromium and asbestos, pose actual risks to humans. Others pose only a theoretical risk to laboratory animals.

The list also includes consumer products like aspirin, traditional foods such as alcoholic beverages and betel nut, essential nutrients like selenium and Vitamin A, and byproducts of industry like soot and diesel exhaust. It even includes hormones produced naturally in the human body, such as progesterone and testosterone.

Substances are added to the list regularly. When the federal Environmental Protection Agency lists a new substance as a possible cause of cancer in laboratory animals, that substance is added to the Proposition 65 list. The fact that there is no evidence of human carcinogenicity does not stop OEHHA from listing it. When the Legislature or the Department of Labor require information for employees who use a substance in their jobs, that substance is added to the list.

The fact that it is dangerous only to people who are exposed to large amounts does not stop OEHHA from listing it. Although the listing decisions are reviewed by scientists appointed to Advisory Panels by the governor, the Proposition 65 rules do not allow the scientists to consider whether there is any real danger from the substance, when they are deciding whether to list it.

For the most current Proposition 65 listing, visit OEHHA website