Proposition 65 mandates that the Governor of California maintain and publish a list of chemicals that are known to cause cancer, birth defects and/or other reproductive harm. The list, which must be updated annually, includes a wide variety of chemicals that can be found in dyes, solvents, drugs, food-additives, by-products of certain processes, pesticides and tobacco products.
A chemical can be listed if it has been classified as a carcinogen or as a reproductive toxicant by an organization deemed "authoritative" on the subject. For carcinogens, the U.S. Environmental Protection Agency, U.S. Food and Drug Administration, National Institute for Occupational Safety and Health, the National Toxicology Program, and the International Agency for Research on Cancer are deemed authoritative. With respect to reproductive toxicants, the authorities are the U.S. Environmental Protection Agency, U.S. Food and Drug Administration, National Institute for Occupational Safety and Health, and International Agency for Research on Cancer. A chemical can also be listed if it is required to be labeled or identified as a carcinogen or as a reproductive toxicant by an agency of the state or federal government.
A company with ten or more employees that operates within the State of California (or sells products in California) must comply with the requirements of Proposition 65. To comply, businesses are: (1) prohibited from knowingly discharging listed chemicals into sources of drinking water; and (2) required to provide a "clear and reasonable" warning before knowingly and intentionally exposing anyone to a listed chemical.