Prop 65 for importers: who it applies to and what it actually requires

There is no registration, no filing and no approval. There is one duty, three exemptions, and a private enforcement system that does the work.

Proposition 65 confuses people because they look for the process — the registration, the filing, the approval — and there isn't one. There is a single duty, a short list of exemptions, and a private enforcement system that supplies all the pressure.

Checked against the statute and regulations on September 29, 2026.

The whole obligation, in one sentence

Health & Safety Code §25249.6:

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 to such individual, except as provided in Section 25249.10.

That's it. Nothing is submitted to anybody. You warn, or you establish that you don't have to.

Are you covered?

Almost certainly, if you sell into California. §25249.11(b) excludes "any person employing fewer than 10 employees", plus government bodies and public water systems. There is no importer carve-out, no revenue threshold, and no distinction in the statute between a brand and a reseller. (The regulations do allocate who provides the warning: 27 CCR §25600.2 puts it primarily on the manufacturer, producer, packager, importer, supplier or distributor, and limits a retailer's responsibility.)

Note what the threshold is not: it is employees, not California employees, and not sales.

The three exemptions

§25249.10 gives you exactly three routes out:

1. Federal preemption — an exposure for which federal law governs warning in a manner that preempts state authority.
2. The 12-month grace. An exposure "that takes place less than twelve months subsequent to the listing of the chemical". A newly listed chemical does not require a warning for a year.
3. Below the risk level. No significant risk assuming lifetime exposure for carcinogens; no observable effect at 1,000 times the level in question for reproductive toxicants.

⚠️ Read the last line of §25249.10(c): "the burden of showing that an exposure meets the criteria of this subdivision shall be on the defendant." The third exemption is real, and it is yours to prove — after you have been sued. It is not a defense you can rely on casually.

What a compliant warning looks like

The safe-harbor content is at 27 CCR §25603. The long-form consumer product warning needs the yellow triangle symbol with a black exclamation point (black and white is allowed where the label isn't printed in yellow), the word WARNING: (or CA WARNING / CALIFORNIA WARNING) in bold capitals, and text naming one or more chemicals:

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. For more information go to www.P65Warnings.ca.gov.

Separate wordings exist for reproductive toxicants and for both endpoints together, and §25601(b) requires a chemical name for each endpoint where a warning covers both.

The safe harbor is optional in principle — the statute only asks for a "clear and reasonable" warning — but stepping outside it means arguing about adequacy with someone who has already sued you.

How enforcement actually happens

Mostly not by an inspector. The Attorney General, district attorneys and some city attorneys can sue, but much of the enforcement comes from private plaintiffs, who must first serve a 60-day notice (§25249.7(d)). We cover what to do when one arrives separately — the short version is that the clock is real and the response window is where the outcome is decided.

What this means practically

• The listed chemical is the unit of analysis, not the product. You need to know what is in the product, which means supplier declarations again.
• A warning is cheap; an unnecessary one is not free. Over-warning has its own commercial cost and, on a marketplace listing, its own conversion cost.
• The list moves. The statute (§25249.8) requires it to be revised at least once a year, and each addition starts a 12-month clock — see when OEHHA adds a chemical.

General information, not legal advice. Every requirement links to the statute or regulation — check those and talk to counsel about your products.