Companies doing business in the US state of California need to be aware of Proposition 65, otherwise known as Prop 65, or, the ‘Safe Drinking Water and Toxic Enforcement Act of 1986”.


SGS has been helping businesses understand and comply with Proposition 65 since its enforcement and, following a recent training webinar, we thought it was time to once again take an overview of Proposition 65 by looking at some of the most commonly asked questions. 

What is Proposition 65?

Prop 65 is a California voter initiative designed to protect citizens and sources of drinking water from harmful chemicals.

What are the requirements of Prop 65?

The State is required to maintain and publish a list of chemicals known to cause cancer, birth defects or other reproductive harm. The list is administered by the Office of Environmental Health Hazard Assessment (OEHHA) and is updated at least once a year. First published in 1986, the list now includes approximately 900 chemicals.

Once a chemical is listed, businesses are required to:

  • Provide a "clear and reasonable" warning before knowingly and intentionally exposing anyone to a listed chemical. This warning can be given by a variety of means, such as by labeling a consumer product, posting signs at the workplace, distributing notices at a rental housing complex, or publishing notices in a newspaper. Enforcement begins twelve months after listing
  • Cease discharging listed chemicals into sources of drinking water. Enforcement begins 20 months after listing

Are there exemptions?

Yes, these include:

  • Governmental agencies and public water utilities
  • Businesses with nine or fewer employees
  • Exposures that pose no significant risk of cancer
  • Exposures that will produce no observable reproductive effect at 1,000 times the level in question
  • Exposures to listed chemicals that occur naturally in foods
  • Discharges that do not result in a "significant amount" of the listed chemical entering any source of drinking water

What is the Prop 65 List?

The list contains a wide range of naturally occurring and synthetic chemicals that are known to cause cancer, birth defects or other forms of reproductive harm. They include additives or ingredients in pesticides, common household products, food, drugs, dyes, or solvents. They can also be chemicals used in manufacturing and construction, or byproducts of chemical processes, such as motor vehicle exhaust.

The list contains information on the chemical, the type of toxicity, its listing mechanism, CAS Number, the date it was listed, and any safe harbor level. View the Proposition 65 List.

What are safe harbor levels?

The OEHHA has established over 300 safe harbor levels. These include:

  • No Significant Risk Levels (NSRLs) for cancer-causing chemicals
  • Maximum Allowable Dose Levels (MADLs) for chemicals causing reproductive toxicity

A safe harbor level is a daily exposure limit (µg/day). It is completely different to the chemical total content of a product (mg/Kg) and there is no way to directly convert one figure into the other as they are different conceptual measurements.

How do you determine if a Proposition 65 warning label is needed?

Commonly known as a ‘Prop 65 warning’, it must be applied to any product containing a listed chemical, unless the level of exposure is below the regulatory safe harbor level. Firstly, check whether the chemical is listed and, if it is, whether the level in the product exceeds the safe harbor level. If it is not listed, or the level is below the safe harbor level, no ‘Prop 65 warning’ is required.

Who enforces Proposition 65?

It is enforced by the California Attorney General's Office, and also district attorneys, city attorneys (with a population exceeding 750,000), and, if no attorney’s office has taken action, individuals acting in the public interest.

Individuals act by filing a lawsuit against a business alleged to be in violation of the law. They must first provide at least a 60-day notice to the business, as well as one to the Attorney General and the appropriate district attorney and/or city attorney. 

How does Proposition 65 affect consumer products?

Products that expose individuals to listed chemicals must contain a ‘Prop 65 warning’. Businesses making and selling products in California that fail to comply with this rule are liable to civil penalties of $2,500 per day for each violation.

What should a business do if there is no safe harbor level?

Where the OEHHA has not defined a NSRL or MADL, businesses should provide a ‘Prop 65 warning’. Businesses can be exempt if they can show that the anticipated exposure level will not pose a significant risk of cancer or reproductive harm. Stakeholders should refer to Article 7 and Article 8 of Title 27, for OEHHA guidance on how to calculate levels for chemicals without safe harbor levels.

What are the warnings for consumer products?

The content of the warning should include:

  • Warning symbol consisting of a black exclamation point in a yellow equilateral triangle with a bold black outline and the word WARNING in bold type
  •  For exposures to listed carcinogens/reproductive toxicants, the words, “This product can expose you to chemicals including [name of one or more chemicals], which is [are] known to the State of California to cause cancer/birth defects or other reproductive harm. For more information go to”

The on-product (short-form) warning should use the following elements:

  • Warning symbol consisting of a black exclamation point in a yellow equilateral triangle with a bold black outline and the word WARNING in bold type
  • For consumer products that cause exposures to both a listed carcinogen and a reproductive toxicant, the words, “Cancer/birth defects or other reproductive harm -

What are the requirements on font size and language for ‘Prop 65 Warnings’?

Warnings on consumer product packaging must be at least as large as the other informational type and not smaller than 6-point type. If the label has information in languages other than English, the warning must be provided in all languages used on the package. If an on-product (short-form) warning is provided on the product label, the warning with the same content may also be used for catalog and internet purchases. This version cannot be used on a sign.

Who is responsible for providing warnings?

Since August 2017, the primary responsibility has been on product manufacturers, producers, packagers, importers, suppliers and/or distributors. For consumer product exposures, businesses in the above categories must either provide a warning on the product, or provide notice and warning materials to “the authorized agent” for a retail seller and receive an acknowledgment that the notice and materials were received. The retail seller is responsible for placement and maintenance of the warning materials they have received.

‘Products Meeting Federal Standards Don’t Need Prop 65 Warnings.” is this correct?

No. The warning requirement is based on exposure and not chemical total content. It is therefore possible for a product to meet federal standards but still require a clear and reasonable warning.

What should a business do if it receives a 60-day notice from a private attorney?

  • Seek advice of a legal counsel who specializes in Prop 65 to evaluate the matter
  • Assess the validity of the claim. This may require laboratory testing on exposure levels
  • If the plaintiff’s claim is deemed valid:
    • Cease sale of the product
    • Instruct retailers to stop selling the product
    • Instigate product recall
    • New products must have a Prop 65 warning

When must products comply with the new rules for ‘clear and reasonable warnings’?

August 30, 2018. Until this date, products can use either the new form of warning or the September 2008 regulations. After this date, new products must only use the new regulations.

Consumer products manufactured prior to August 30, 2018, do not require the new warning, as long as it is labeled with a warning that is compliant with the September 2008 regulations.

SGS Solutions: Prop 65 Services

Through its global network of high-tech laboratories, SGS offers a comprehensive range of testing, product assessment and consultancy services for businesses operating in California. In addition to helping mitigate risk, we also offer training and information services to help businesses stay up-to-date with the latest developments with Prop 65 regulations. Learn more about SGS’s Prop 65 Services.

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For more information, contact:

Hsin Chen (Rick)
Technical Manager - Restricted Substances
SGS - North America, Inc.
t: +1 (973) 461-7950