Prop 65 Compliance for Shopify Sellers

What Proposition 65 requires

Proposition 65 — the Safe Drinking Water and Toxic Enforcement Act of 1986 — requires businesses to give a "clear and reasonable" warning before knowingly exposing California consumers to any of the 900+ listed chemicals known to cause cancer, birth defects, or reproductive harm.

There is no revenue or size exemption for online sales: if you sell to anyone in California, the law applies. For e-commerce, the warning must appear on the product listing page before purchase is completed — not buried in fine print or sent only in a post-purchase email.

How to add a compliant warning

Use the standard safe-harbor warning so it is presumed "clear and reasonable." The required language is: "WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or reproductive harm. For more information go to www.P65Warnings.ca.gov." Where you know the specific chemical, name it (for example, lead or di(2-ethylhexyl)phthalate).

Do not claim a product is "Prop 65 free" or "exempt" — unsubstantiated exemption claims can themselves trigger enforcement. If no warning is required, simply omit Prop 65 language rather than advertising an exemption.

Adding Prop 65 warnings on Shopify

Shopify stores ship directly to consumers, including Californians, so the Prop 65 warning must appear on your own product pages before checkout. The warning must be visible to the buyer before purchase is completed, so place it directly on the listing rather than only in confirmation emails or packaging inserts. Cosmetics, supplements, jewelry, electronics, and home fragrance are among the most commonly affected categories, but any product containing a listed chemical above the safe-harbor level can require a warning. Review each product against the chemical list and, where a listed chemical is present above the safe-harbor level, add the standard safe-harbor warning naming the specific chemical where you know it.

Frequently Asked Questions