Overview
Proposition 65 is a California law, formally the Safe Drinking Water and Toxic Enforcement Act of 1986. It does not ban chemicals. Instead it forces businesses to warn people before exposing them to substances the state has listed as causing cancer or reproductive harm.
The duty is a warning, not a ban. A product that can expose a person to a listed chemical must carry a clear and reasonable warning before that exposure happens.
How it works
The state keeps a list of chemicals known to cause cancer or reproductive harm. The list holds hundreds of substances and grows as new ones are added. When a product, workplace, or location can expose a person to one of these chemicals, the responsible business must give a warning that a person would notice and understand.
What makes Prop 65 distinctive is enforcement. Alongside state action, private individuals and groups can bring lawsuits against companies they believe failed to warn. This private enforcement route is active and well known, which is why any company selling into California treats Prop 65 as a standing compliance concern.
Why it matters for sellers
Because the warning duty attaches to exposure rather than to a fixed product category, a wide range of goods can fall in scope. A business that sells into California cannot assume its products are exempt simply because they comply with federal rules. The lawsuit-driven enforcement means a missing warning can become a costly dispute.
How it relates to other topics
- TSCA is the federal chemicals law that sits above state rules like this one.
- The hazard classes behind many listings overlap with CMR substances, those that are carcinogenic, mutagenic or toxic for reproduction.
- The idea of flagging substances of concern parallels the EU concept of SVHC.
Note: general educational information, not legal advice. Check the official source before relying on it.