California’s Proposition 65 is a state law that requires businesses to warn people before exposing them to chemicals the state has identified as causing cancer or reproductive harm, and it prohibits those same businesses from discharging the listed chemicals into drinking water sources.1California Legislative Information. California Code Health and Safety Code 25249.6 – Required Warning Before Exposure to Chemicals Known to Cause Cancer or Reproductive Toxicity Officially the Safe Drinking Water and Toxic Enforcement Act of 1986, the law does not ban any chemical outright. It forces disclosure so that consumers, workers, and residents can decide for themselves whether to accept the exposure.
The Chemical List That Drives Everything
Every obligation under Proposition 65 traces back to a single document: the official list of chemicals the state has identified as causing cancer or reproductive toxicity. The Office of Environmental Health Hazard Assessment (OEHHA) maintains it, evaluates the underlying science, and recommends additions.2Legal Information Institute. California Code of Regulations Title 27 Section 25306 – Chemicals Formally Identified by Authoritative Bodies The list must be revised and republished at least once a year.3California Legislative Information. California Code Health and Safety Code HSC 25249.8
Roughly 900 substances are on it today. They include heavy metals such as lead and mercury, synthetic manufacturing compounds, certain pesticides, pharmaceutical byproducts, and chemicals found in everyday goods like plastics and cleaning products. A chemical can land on the list through several pathways, one of which is formal identification by an authoritative body such as the International Agency for Research on Cancer or the U.S. Environmental Protection Agency.
The Warning Requirement
When a business knowingly and intentionally exposes anyone to a listed chemical, it must first give a “clear and reasonable warning.”1California Legislative Information. California Code Health and Safety Code 25249.6 – Required Warning Before Exposure to Chemicals Known to Cause Cancer or Reproductive Toxicity The duty is broad. It reaches product labels in stores, signs posted where workers encounter listed chemicals, notices in apartment buildings, and any other commercial setting where someone could be exposed. The chemical does not have to leave the market. People just have to be told it is there.
Safe Harbor Format
A business can write its own warning language, but doing so invites later arguments about whether the wording was “clear and reasonable.” Most companies use the state’s safe harbor warning format instead, which lays out specific language and design rules that satisfy the statute as a matter of law when followed precisely.
The required symbol is a black exclamation point inside a yellow equilateral triangle with a bold black outline, placed to the left of the warning text. The symbol must be at least as tall as the word “WARNING.” On labels or signs that are not printed in color, a black-and-white version is acceptable.4Proposition 65 Warnings Website. Warning Symbol
OEHHA updated the short-form warning regulations effective January 1, 2025. The main change: short-form warnings must now name at least one chemical, which makes labels more informative than the older generic versions. Businesses using the prior short-form format have a three-year transition period ending January 1, 2028, to update their labels.5Office of Environmental Health Hazard Assessment. Proposition 65 Clear and Reasonable Warnings – Safe Harbor Methods and Content The update also added tailored safe harbor warnings for motor vehicle parts and recreational marine vessel parts.
Online and Catalog Sales
Online sellers cannot bury the warning in a site-wide FAQ. For internet sales, a safe harbor warning must appear on the product display page itself, through a clearly marked hyperlink using the word “WARNING” (or “CA WARNING” or “CALIFORNIA WARNING”) on that page, or through another prominent method delivered before the purchaser completes the transaction.6Legal Information Institute. California Code of Regulations Title 27 Section 25602 – Methods of Transmission QR codes and barcodes do not qualify, because the consumer has to take an extra step to see what the warning says.7Proposition 65 Warnings Website. Frequently Asked Questions for Businesses
Printed catalogs must tie the warning to the specific product. One option is placing the full warning text next to the product listing. Another is putting a symbol next to the item and running the warning text at the bottom of the page. A warning must also appear on or with the product itself when it ships.7Proposition 65 Warnings Website. Frequently Asked Questions for Businesses When a manufacturer or supplier sends an updated short-form warning, online retailers have up to 60 calendar days to post the new version.6Legal Information Institute. California Code of Regulations Title 27 Section 25602 – Methods of Transmission
Foreign Language Warnings
If a business provides consumer information or signage for a product in a language other than English, the Proposition 65 warning must appear in that language too. OEHHA publishes translated sample warnings for businesses that need them.8Proposition 65 Warnings Website. Sample Warnings and Translations for Businesses
The Drinking Water Discharge Ban
The second obligation is environmental. Businesses cannot knowingly discharge or release a listed chemical into water, or onto land where it is likely to pass into a source of drinking water.9California Legislative Information. California Code Health and Safety Code 25249.5 – Prohibition on Contaminating Drinking Water with Chemicals Known to Cause Cancer or Reproductive Toxicity “Source of drinking water” is defined broadly: it covers any water currently used for drinking and any water designated as suitable for domestic or municipal use in a water quality control plan adopted by a regional board.10California Legislative Information. California Code Health and Safety Code 25249.11 That reaches active reservoirs, aquifers, and groundwater basins identified in state planning documents, even if nobody is drawing drinking water from them right now.
The violation is the discharge itself. No one has to prove a person actually drank contaminated water. A company that lets a listed chemical seep into protected groundwater has broken the law whether or not the contamination ever reaches a tap.
Grace Periods for Newly Listed Chemicals
Compliance is not expected overnight when OEHHA adds a chemical. Two separate grace periods apply. The warning requirement does not take effect until 12 months after a chemical is listed, giving businesses time to reformulate products or redesign labels.11Office of Environmental Health Hazard Assessment. Appendix A – Proposition 65 Summary The discharge prohibition has a longer runway: it does not apply to any release occurring within 20 months of the listing date.12California Legislative Information. California Code Health and Safety Code HSC 25249.9 Once the grace period expires, penalties can accrue daily, so the cutoff dates are worth tracking.
Who Is Exempt
Not every entity or every exposure triggers Proposition 65. The statute’s definition of “person in the course of doing business” excludes three groups: businesses with fewer than ten employees, government agencies at every level, and public water systems.10California Legislative Information. California Code Health and Safety Code 25249.11 The small-business exemption is a straight headcount. A company with nine employees falls outside both the warning and discharge rules.
Even for larger businesses, the warning and discharge obligations are waived when exposures stay below established safety levels. For carcinogens, the benchmark is the “No Significant Risk Level” (NSRL), set at the exposure that would cause no more than one additional cancer case per 100,000 people over a 70-year lifetime. For reproductive toxicants, the benchmark is the “Maximum Allowable Dose Level” (MADL), calculated at one-thousandth of the highest dose at which no observable reproductive harm was found in studies. OEHHA publishes specific NSRL and MADL values for many listed chemicals. A business claiming the exemption has to prove through scientific data that its exposure stays below the applicable threshold.13New York Codes, Rules and Regulations. 27 CCR 25721 – Level of Exposure to Chemicals Causing Cancer
Penalties and Who Can Sue
Proposition 65 has teeth because both the government and private citizens can enforce it. The California Attorney General, district attorneys, and city attorneys in cities with populations over 750,000 can bring civil actions. Government enforcers can seek injunctions and civil penalties of up to $2,500 per day for each violation.14California Legislative Information. California Code Health and Safety Code HSC 25249.7 For a business selling multiple non-compliant products, daily fines stack quickly.
The law also contains a “private attorney general” provision, and most enforcement actually happens there. Before suing, a private enforcer must serve a 60-day notice of violation on the alleged violator and on the Attorney General, district attorney, or city attorney with jurisdiction. During that window, a government prosecutor can step in and take the case. If none does, the private party can proceed. Since 2002, private enforcers alleging a warning violation must also include a certificate of merit stating that they consulted with someone who has relevant expertise, that the expert reviewed facts and data regarding the exposure, and that there is a reasonable and meritorious basis for the action.14California Legislative Information. California Code Health and Safety Code HSC 25249.7
Collected penalties are split: 75 percent goes to the Safe Drinking Water and Toxic Enforcement Fund administered by OEHHA, and 25 percent goes to the office that brought the action. In private enforcement cases, that 25 percent goes to the plaintiff.15California Legislative Information. California Code Health and Safety Code 25249.12 Settlements commonly add reimbursement of the plaintiff’s attorney fees and costs on top of the penalties.
If You Receive a 60-Day Notice
A 60-day notice may come from a well-funded advocacy group pursuing genuine public health goals or from a serial plaintiff whose primary aim is a fee-driven settlement. The California Attorney General’s office has documented concerns about the private enforcement system, including excessive attorney fee recoveries relative to any actual public health benefit, settlements built on negligible or implausible exposure scenarios, and the diversion of what should be penalty money into “Additional Settlement Payments” with no clear link to the violation or to California.16California Attorney General. Initial Statement of Reasons – Proposition 65 Private Enforcement Either way, the legal clock starts the day the notice arrives, and getting counsel involved quickly is the safest response.