Proposition 65, the Safe Drinking Water and Toxic Enforcement Act of 1986, was passed by California voters with two goals in mind: to protect drinking water from toxic substances and to reduce or eliminate exposures to toxic substances by requiring warnings on consumer products. The legislation requires cosmetics manufacturers to prove that ingredients in their products pose no significant risk of causing cancer or reproductive toxicity. If not, manufacturers are required to include a warning label on any product containing an ingredient believed to cause cancer or reproductive toxicity.