Proposition 65

Proposition 65 is a California state law requiring manufacturers to inform consumers of their exposure to chemicals that cause cancer, birth defects, or reproductive harm.¹

• California maintains a list of these harmful substances, which currently contains over 900 chemicals.

Proposition 65 is the reason why many consumer products, from potato chips to bathing suits, are sold with labels vaguely warning of potential health risks.² Manufacturers are required to label all products containing them.

History

• The law was passed in 1987, when worries over water pollution drove 40% of Californians to avoid drinking tap water, according to a 1986 poll.²
• Since then, the law has expanded to cover basically everything with a health risk — diluting the law’s ability to raise awareness of products that have the most potential to harm human health.

Sensitivity

• The Prop 65 standard has been critiqued for being too sensitive. For example, chemicals known to cause birth defects are required to be reported at the one-thousandth level— meaning they are reported at levels far below those at which they are able to cause defects.² The California Office of Environmental Health Hazard Assessment explains that this level of caution is necessary to provide the largest safety margins possible.⁴
• Having such high sensitivity means that all products are labeled as being equally hazardous, regardless of the actual variations in their chemical compositions. When all products are labeled as potentially toxic, consumers aren’t able to account for these variations, and as such, may not be able to make well-informed decisions.

Successes

• Despite the issues with sensitivity, Prop 65 has been effective at removing toxic chemicals from the market. Successes include:

1. Reduction of Formaldehyde in Engineered Wood Products

• Before Prop 65: Formaldehyde was widely used as a binder in plywood, particleboard, and medium-density fiberboard (MDF), contributing to indoor air pollution.⁵
• Impact: Proposition 65 raised awareness about the health risks associated with formaldehyde, leading to tighter standards such as the California Air Resources Board (CARB) regulations for formaldehyde emissions. These standards have set global benchmarks, and manufacturers now produce low-emitting or no-added formaldehyde (NAF) products.⁵

2. Elimination of Lead in Plumbing Fixtures

• Before Prop 65: Lead was commonly found in faucets, pipes, and other plumbing components, contributing to contamination of drinking water.⁶
• Impact: Proposition 65 warnings on lead-containing products helped drive the adoption of stricter regulations, including the Reduction of Lead in Drinking Water Act. Many manufacturers now produce lead-free or low-lead fixtures to meet compliance.⁶

3. Shift Away from Harmful Flame Retardants

• Before Prop 65: Flame retardants, such as polybrominated diphenyl ethers (PBDEs), were used extensively in insulation and foam products but posed significant health risks. ⁷
• Impact: Proposition 65 has supported the push for flame-retardant-free materials, leading to safer insulation options like cellulose or mineral wool.⁷

Main Takeaways

• While critics of Proposition 65 raise important points about the law’s over-sensitivity, it’s equally important to recognize its successes in removing toxic chemicals from the market.
• Proposition 65 has had a noteworthy influence on national politics, influencing standards in other states and forcing manufacturers to label their products, regardless of their locality to the state of California.

To hear more about Proposition 65’s victories in consumer health, check out this page by the Center for Environmental Health.³