California Proposition 65, often referred to as Prop 65 is the Safe Drinking Water and Toxic Enforcement Act of 1986.
Those doing business in California may not expose individuals to chemicals known to cause cancer or reproductive toxicity without giving reasonable warning. Nor may such chemicals be discharged into drinking water.
Prop 65 requires the State to publish a list of chemicals known to be carcinogens or cause birth defects or reproductive harm. The list was first published in 1987 and is updated every year. There are currently over 850 chemicals and substances on the list.
Warnings can be given by such as labelling a consumer product, posting signs at the workplace, distributing notices or utilising newspapers.
Warnings should say:
Carcinogens: WARNING-This product contains a chemical known to the State of California to cause cancer.
Reproductive toxins: WARNING-This product contains a chemical known to the State of California to cause birth defects or other reproductive harm.
While this has been around a long time it would be well worth looking in to further if you were intending to sell a product in to this State.