California’s Proposition 65 (“Prop 65”), formally entitled “The Safe Drinking Water and Toxic Enforcement Act” of 1986, is a law that aims to protect drinking water sources from certain chemicals that could potentially cause birth defects and cancer. It also aims to eliminate or reduce exposures to such chemicals by providing advance notice to consumers about the contents of the products that they purchase.

Prop 65 also requires California state to keep an updated list of those chemicals that are known to cause cancer, reproductive harm, or birth defects. Thus, if a business manufactures products that contain a substantial amount of a chemical from this list, then it must give “clear and reasonable” warning to California residents. A business can notify consumers by either posting a sign or using a product label with a warning.

Additionally, businesses are prohibited from knowingly discharging large amounts of any listed chemicals into drinking water sources under the law.

Although California’s Prop 65 requires businesses to warn consumers about a product even if it only has small doses of a chemical. They must also add a chemical to a list even if it only has the potential (as opposed to actual proof) to cause health issues, the law was intended to give state residents the choice to put themselves at risk.

In other words, the law grants both residents and the state the right to make informed decisions about the chemicals they expose themselves to and what the state should regulate.

What are the Elements of Proposition 65?

Although businesses must abide by all sections of Prop 65, there are two sections in particular that are important for compliance purposes. These sections provide explicit guidance on the main requirements of Prop 65.

The text of Prop 65 states that, “no person in the course of doing business shall knowingly discharge […] a chemical known to the state to cause cancer or reproductive toxicity into water or onto […] land where such chemical passes or probably will pass into any source of drinking water…” (Section 25249.5). This section specifically pertains to the law’s discharge and release prohibitions.

The second section that businesses should focus on provides that, “no person in the course of doing business shall knowingly and intentionally expose any individual to a chemical known to the state to cause cancer or reproductive toxicity without first giving clear and reasonable warning…” (Section 25249.6). This second section specifically pertains to the law’s warning and notice requirements.

To determine whether a business must comply with the law’s discharge prohibitions and warning requirements, it should review the chemicals on the Prop 65 List. Once a chemical is added to this list, businesses will have 12 months from the date it was listed to comply with the warning requirement. Businesses will also have 20 months to comply with the discharge prohibition under the law.

A business may be exempt from the requirements of Prop 65 if it has less than 10 employees or if it is a government agency. A business will also be exempt from the warning and discharge requirements if exposure to a chemical is so low that it would not create any risks.

To determine whether chemical levels are low enough to exempt a business, the California Office of Environmental Health Hazard Assessment (OEHHA), the government agency who maintains the list and is responsible for enforcing Prop 65, has developed guidelines called, “safe harbor levels.” Businesses should review the chemical amounts provided by the safe harbor levels guide to ensure they are following the law.

Finally, as previously mentioned, businesses that are not exempt must give “clear and reasonable” warning before intentionally or knowingly exposing consumers to a listed chemical. A “clear and reasonable” warning can be provided in a number of ways, such as posting signs, labeling a product, giving out flyers in a building or housing complex, and/or publishing notices in a local newspaper.

Failure to abide by Prop 65 requirements can result in serious penalties.

What Types of Chemicals are on the List?

Since the initial publishing of the list in 1987, over 1,000 chemicals to date have been found to cause cancer, reproductive harm, and/or birth defects. The list contains a wide range of both naturally occurring and synthetic chemicals that may be components of common household items, such as food ingredients, pharmaceuticals, solvents, and so on. They may also be used in activities like manufacturing, or could be byproducts of chemicals (e.g., car exhaust).

Some of the chemicals on the Prop 65 California chemical components list include:

    • Cancer-inducing chemicals:
      • Alcoholic beverages (associated with alcohol abuse);
      • Cobalt sulfate;
      • Isoprene;
      • Lead phosphate;
      • Nickel;
      • Phenobarbital; and
      • Wood dust.


    • Chemicals that are harmful to the reproductive system:
      • Anabolic steroids (both male and female reproductive systems);
      • Cocaine (both male and female reproductive systems);
      • Etodolac (female reproductive system only);
      • DDT (both male and female reproductive systems);
      • Tobacco smoke (both male and female reproductive systems); and
      • Trichloroethylene (male reproductive system only).


  • Chemicals that cause developmental (birth) defects:
    • Benzene;
    • Ethyl alcohol (in alcoholic beverages);
    • Halazepam;
    • Mercury and mercury compounds;
    • Oxymetholone;
    • Retinol; and
    • Temazepam.

Note that some of the above chemicals are listed in overlapping categories. To view other chemicals contained on the Prop 65 List, individuals and businesses can visit the OEHHA’s website.

While it may appear as if every chemical has already been added to this list, not every chemical submitted makes it on the official list. The text of Prop 65 defines four ways in how a chemical may be selected for regulation:

    • Labor Code sections 6382(b)(1) and (d) contain chemicals identified by the World Health Organization’s International Agency for Research on Cancer (“IRAC”) that cause cancer in humans and/or laboratory animals. Such chemicals may be added to the Prop 65 List.


    • Chemicals that have been identified by certain authoritative bodies (e.g., U.S. Food and Drug Administration, U.S. Environmental Protection Agency, etc.) to cause cancer, birth defects, or reproductive harm.


    • Chemicals that have been found to cause such health issues and have been identified by California’s State Qualified Experts (i.e., the Carcinogen Identification Committee (CIC) and the Developmental and Reproductive Toxicant Identification Committee (DARTIC)).


  • If a California state or federal government agency requires that a chemical be labeled to cause such issues, then it will make the Prop 65 list as well.

Although each of the four categories above have their own procedures to list and/or delist chemicals, they generally all involve the following basic requirements:

  • Public notice that a chemical is being considered for the Prop 65 list;
  • A certain period of time for public comment;
  • A second period of time to review the public comments received; and
  • Notification and publication of a final decision.

What is Considered a Clear and Reasonable Warning?

Before defining what a clear and reasonable warning is, a business must first determine when a Proposition 65 warning required. As previously mentioned, a Prop 65 warning is required when a business has more than 10 employees, is not a government agency, uses a chemical that is on the Prop 65 List, and those chemicals exceed the OEHHA’s safe harbor levels.

Prior to 2018, a business did not have to list which particular chemical in their products were causing health issues. Thus, any products made before 2018 will not have to list such chemicals. For chemicals made after 2018, however, businesses will need to list at least one chemical of concern, but does not have to list all of them if the product contains more than one of the listed chemicals.

Products made after 2018 should provide a warning akin to the following:

  • “Warning: This product can expose a consumer to X chemical, which is known to the State of California to cause either cancer, birth defects, or reproductive harm.”

Although it is not necessary to use this exact phrase, businesses must use a similar warning and that warning must be “clear and reasonable” in order to comply with the provisions of Prop 65.

Who Must Follow Proposition 65?

Prop 65 applies to all businesses operating in California that have more than 10 employees. If the business has less than 10 employees or is a government agency, then it will be exempted from the requirements of Prop 65.

Additionally, if a business can prove that a chemical does not pose a significant risk or that a chemical falls below the level necessary to cause such risks, then it will be exempted from the law’s requirements as well.

What are the Consequences for Violating Proposition 65?

Businesses that violate Prop 65 may have to pay fines as high as $2,500 per day. Depending on the circumstances, a Prop 65 lawsuit may also be filed against a business. Any district or city attorney in cities whose populations exceed 750,000, or any individual representing public interest (e.g., Attorney General’s office, consumer advocacy groups, law firms, private citizens, etc.) may file a Prop 65 lawsuit.

Prop 65 lawsuits can result in an award of attorney’s fees and costs, injunctive relief, and an additional $2,500 per day if a public prosecutor files an unfair business practice claim as part of the Prop 65 lawsuit.

A business may also opt to settle a lawsuit by following Prop 65 settlement guidelines. Before a court approves a settlement offer, it must find:

  • That the warning being requested by the settlement complies with Prop 65 requirements;
  • That the settlement is in the interest of the public;
  • The amount of attorney’s fees and costs are reasonable under state law; and
  • That penalties comport with specific statute criteria and are found to be reasonable.

Additionally, all private Prop 65 settlements must be reported to the California Attorney General and they must receive advance notice (i.e., 45 days) before a court settlement.

Should I Contact an Attorney?

Given that Proposition 65 can result in serious penalties and heavy fines, it may be in your best interest to speak to a Proposition 65 litigation attorney for further Prop 65 legal advice.

A Prop 65 litigation attorney can check to make sure that your business is in full compliance with Prop 65, answer any questions or concerns you may have about the law, and discuss the next steps you should take if your business has received a Notice of Violation.