Cal. Health & Safety Code §§ 25249.6–25249.12; Title 27, Cal. Code of Regulations, Article 6 (§§ 25600–25607.53, Clear and Reasonable Warnings)

In force

California Proposition 65 (Safe Drinking Water and Toxic Enforcement Act of 1986)

California law requiring businesses to give a clear and reasonable warning before knowingly and intentionally exposing anyone in California to a chemical on the state's Proposition 65 list, and prohibiting knowing discharges of listed chemicals into drinking water sources. It is a warning law, not a ban — products containing listed chemicals may still be sold if properly warned.

Read the official text

Applies to

Businesses with 10 or more employees that operate in or sell products into California, across all product categories (consumer products, food, and premises exposures). Businesses with fewer than 10 employees and government agencies are exempt from the warning requirement and the discharge prohibition.

Key obligations

01Provide a clear and reasonable warning before knowingly and intentionally exposing anyone in California to a chemical listed under Proposition 65, unless the exposure is low enough to qualify for an exemption.source
02Do not knowingly discharge listed chemicals into sources of drinking water in California.source
03Track the chemical list: OEHHA maintains the list, which must be updated at least once a year and has grown to include over 800 chemicals (naturally occurring and synthetic) listed for cancer, birth defects or other reproductive harm since first publication in 1987. The current list is dated December 8, 2025.source
04Once a chemical is newly listed, businesses have 12 months before the warning requirement takes effect for that chemical.source
05If using the safe harbor warning for consumer products (27 CCR 25603), the warning must include the yellow-triangle exclamation symbol, the signal word "WARNING:" (or "CA WARNING:" / "CALIFORNIA WARNING:"), and specified text naming at least one listed chemical, e.g. "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...".source
06Short-form warnings: amendments effective January 1, 2025 require the short-form warning to name at least one chemical (e.g. "Risk of cancer from exposure to [name of chemical]. See www.P65Warnings.ca.gov."). Businesses have a three-year transition; products manufactured and labeled before January 1, 2028 may keep the prior short-form content regardless of when they are sold.source

Conformity routes

Safe harbor warning (27 CCR Article 6)Use OEHHA's safe harbor warning methods and content (Title 27 CCR §§ 25600–25607.53) — warnings that comply are deemed "clear and reasonable" under Health & Safety Code § 25249.6. Warnings in another format are permitted but carry the burden of proving they are clear and reasonable.source
Exposure below safe harbor levels — no warning neededA business has safe harbor from the warning requirement and discharge prohibition if exposure to a chemical occurs at or below OEHHA's safe harbor levels: No Significant Risk Levels (NSRLs) for carcinogens and Maximum Allowable Dose Levels (MADLs) for reproductive toxicants.source
Legacy short-form sell-throughProducts manufactured and labeled prior to January 1, 2028 may use the pre-2025 short-form warning content (e.g. "WARNING: Cancer — www.P65Warnings.ca.gov") regardless of when the product is sold to a consumer.source

Documentation

Warning label / sign artworkNo certificate or government filing is required; compliance is demonstrated by the warning itself (label, shelf sign/tag, or website warning for internet sales) meeting the content and transmission methods of 27 CCR Article 6.source
Written notice to retail sellersThe regulations allocate responsibility along the supply chain: manufacturers/suppliers can discharge their duty by providing a warning or a written notice to the retail seller under 27 CCR 25600.2(b) and (c); for internet purchases before January 1, 2028, a retailer is not responsible for posting an updated short-form warning online until 60 calendar days after receiving an updated warning or written notice.source

Marking requirements

Full-length safe harbor consumer product warning: symbol of a black exclamation point in a yellow equilateral triangle with a bold black outline (black and white permitted where the label is not printed in yellow), placed left of the text at no smaller than the height of the word "WARNING"; the word "WARNING:" (or "CA WARNING:" / "CALIFORNIA WARNING:") in capital letters and bold print; and the prescribed exposure sentence naming one or more listed chemicals (27 CCR 25603(a)).source
Short-form on-label warning: entire warning in a type size no smaller than the largest type size used for other consumer information on the product, and never smaller than 6-point type; from January 1, 2025 the new content options name the chemical, e.g. "Risk of cancer from exposure to [name of chemical]. See www.P65Warnings.ca.gov." (27 CCR 25602(a)(4), 25603(b)).source

Key dates

2016-08-30OAL approved OEHHA's overhauled Article 6 'clear and reasonable warnings' regulations (operative August 30, 2018).source
2018-08-30Current-generation Article 6 warning regulations became operative.source
2025-01-01Short-form warning amendments effective (27 CCR 25601, 25602, 25603, 25607.2 amended; 25607.50–25607.53 added): chemical name required in new short-form content; three-year transition begins.source
2025-12-08Date of the current Proposition 65 chemical list.source
2028-01-01End of short-form transition: products manufactured and labeled from this date must use the new chemical-naming short-form content to keep safe harbor; products manufactured and labeled before this date may be sold with the old short-form indefinitely.source

Penalties

Penalties for violating Proposition 65 by failing to provide required warnings can be as high as $2,500 per violation per day. Enforcement is by the California Attorney General, district attorneys, city attorneys (cities over 750,000), and private individuals acting in the public interest, who must serve a 60-day notice of violation (including on the Attorney General) before suing (Health & Safety Code § 25249.7(d)).source

Further guidance

Frequently asked

Does a Proposition 65 warning mean the product is banned or unsafe?+

No. Prop 65 does not ban any product — it is a right-to-know law. A warning means the business believes the product can expose Californians to a listed chemical above the level where a warning is required (or the business is warning out of caution without measuring exposure).

My business has fewer than 10 employees — do I need to comply?+

Businesses with fewer than 10 employees are exempt from the warning requirement and the discharge prohibition. Be aware, though, that larger businesses in your supply chain (e.g. the retailer selling your product) may still ask you for Prop 65 information contractually.

I sell online from outside California — does Prop 65 apply to me?+

Prop 65 applies to businesses that expose people in California, so products sold into California are in scope. For internet purchases, the safe harbor regulations require the warning on the product display page, via a clearly marked WARNING hyperlink, or otherwise prominently displayed before the purchase is completed.

What changed with the short-form warning in 2025?+

From January 1, 2025, the safe harbor short-form warning must name at least one listed chemical (e.g. "Risk of cancer from exposure to lead. See www.P65Warnings.ca.gov."). There is a three-year transition: products manufactured and labeled before January 1, 2028 may keep the old generic short-form and be sold indefinitely.

How do I know if my exposure is low enough to skip the warning?+

OEHHA publishes safe harbor levels — No Significant Risk Levels for carcinogens and Maximum Allowable Dose Levels for reproductive toxicants. If the exposure your product causes is at or below the applicable level, no warning is required. Where no safe harbor level exists for a chemical, the business bears the burden of showing the exposure poses no significant risk, which usually needs expert assessment.

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