Is a Proposition 65 warning required? This is the question plumbing product manufacturers, distributors and retailers must ask themselves when doing business in the state of California.

Proposition 65, also known as the Safe Drinking Water and Toxics Enforcement Act of 1986, is a regulation administered by the California Office of Environmental Health Hazard Assessment (OEHHA).  It requires companies with 10 or more employees that sell products in California to provide adequate warning about the presence of certain hazardous chemicals in their products. According to the state, “significant exposure” to these chemicals are “known to cause the risk of cancer, birth defects or other reproductive harm.” OEHHA maintains, publishes and updates a list of these chemicals on a regular basis. Today, nearly 1,000 substances make up this list.

Plumbing products sold in California must also comply with national and international industry standards and regulations. As a right-to-know initiative, what Proposition 65 does is provide the state’s citizens additional information about the potential of developing adverse effects from product-associated chemical exposure; information that may not otherwise be disclosed, provided or available. The initiative also prohibits the discharge of “significant amounts” of these chemicals into sources of drinking water. This includes any indirect environmental discharge that may result in the contamination of groundwater sources. 

Enforcement of Proposition 65 is executed through lawsuits filed by the California Attorney General’s office, district attorneys, city attorneys (for cities larger than 750,000 people), consumer advocacy groups and private citizens. When the Attorney General’s office determines a case has sufficient merit, or expert testimony provides evidence that a violation has occurred, a 60-day notice is issued to the accused company. If the defendant cannot refute the basis of the notice within the 60-day timeframe, litigation can proceed. The civil penalty for failing to provide “clear and reasonable” warning about listed chemicals in a product can be as high as $2,500 per violation, per day. This is in addition to the defendant’s own legal fees and possible restitution payments. 

The threshold of required evidence to file a notice of violation is low. The burden of proof falls upon the defendant. And the definition of who can act as an enforcer is very broad. As a result, businesses are incentivized by potential litigation risks to either reduce chemical usage or provide product warnings. 

The liability risks associated with warning disclosures and notification requirements also apply to the full product supply chain, including downstream retailers. The number of filings and settlements has increased from about 1,000 notices in 2013 to more than 2,000 in 2017 and in 2018.

If a company knows or is expected to know (within reason) that its product contains Proposition 65-listed chemicals, it is obligated to provide consumers with a “clear and reasonable” warning, using language and visuals recommended by OEHHA. This warning indicates that the product contains a chemical that is known by the state of California to increase the risk of cancer, birth defects or reproductive harm.

Furthermore, at least one of those chemicals must be clearly identified. A warning label is not required if the company can demonstrate that exposure to the chemical in question does not exceed “safe harbor” levels, i.e. an intake amount (expressed as µg per day) where risk of cancer and reproductive toxicity is considered sufficiently negligible.


Knowing the rules

“Safe harbor” levels that have been established by OEHHA or trained professionals are applicable to all routes of exposure and sourcing, unless otherwise specified. Unlike federal regulations that typically focus on a specific intended use, Proposition 65 applies to the total exposure that occurs as a result of dermal contact, ingestion and/or inhalation of the chemical from the typical intended use of the product. It is important to note that OEHHA has not established “safe harbor” levels for all listed chemicals. Products containing listed chemicals without official “safe harbor” levels still require a warning unless a company “can show that the anticipated exposure level will not pose a significant risk of cancer or reproductive harm.” The establishment of this anticipated exposure level must be consistent with OEHHA guidelines or may refer to authoritative body reference values. 

Proposition 65 serves a consumer right-to-know purpose and its warning obligations apply only to the state of California. It is not necessarily a determination of safe use. In fact, “safe harbor” levels may sometimes be significantly lower than levels determined to be “without significant risk” based on federal regulations. Due to concerns about legal liability and the complexity of segregation in product supply chains, many manufacturers — including plumbing product manufacturers — apply warning labels on the products they sell, regardless of market destination or level of chemical exposure. Companies should know:  

  • Having a listed chemical in a product does not mean a warning is required. An exposure assessment should be conducted to establish if individuals are exposed to less than OEHHA “safe harbor” levels under typical use conditions. If this is the case, an assessment can readily refute any 60-day notice that is filed.
  • OEHHA allows individual companies to derive “safe harbor” levels if one has not been previously established; however, hiring a competent consultant is recommended since the risk assessment from which the “safe harbor” level is derived may have to be defended in court if a notice is filed.
  • Additional warning exemptions do exist that depend on product use, as well as the source of listed chemicals present in the product.

NSF International can help companies, including those in the plumbing product industry, with any issues, concerns or needs related to Proposition 65. For more information, please contact us at