Proposition 65

California Proposition 65, officially known as the Safe Drinking Water and Toxic Enforcement Act of 1986, requires businesses to provide 'clear and reasonable' warnings before knowingly exposing individuals to chemicals known to the state of California to cause cancer, birth defects, or other reproductive harm. Administered by the Office of Environmental Health Hazard Assessment (OEHHA), Prop 65 currently lists over 900 chemicals. Unlike traditional product safety regulations, Prop 65 is a right-to-know law — it does not ban products or set maximum limits, but requires warnings when exposure exceeds 'safe harbor' levels. Despite being a California state law, Prop 65 effectively impacts all businesses selling products to California consumers, making it a de facto national and international compliance requirement.

Prop 65 compliance involves two main approaches: testing products to confirm that listed chemicals are below safe harbor levels (No Significant Risk Levels for carcinogens, Maximum Allowable Dose Levels for reproductive toxins), or providing compliant warning labels. Since August 2018, new warning regulations require specific language, identification of at least one listed chemical, and a link to the P65Warnings.ca.gov website. The law is enforced primarily through private lawsuits — 'bounty hunter' attorneys and organizations can sue businesses for failure to provide adequate warnings, with penalties up to $2,500 per day per violation. This private enforcement mechanism makes Prop 65 uniquely aggressive compared to other product safety laws. Common product categories affected include food and beverages, electronics, furniture, cosmetics, dietary supplements, and building materials. For international sellers, Prop 65 is often the most surprising compliance requirement, as it can apply even to products that fully comply with EPA, FDA, and EU chemical safety regulations.