Clear and Reasonable Warning

A ‘clear and reasonable warning’ is the standard of warning required by Proposition 65 (Health & Safety Code §25249.6) when a business exposes any individual to a listed chemical above the applicable safe harbour level. A warning meets this standard when it is: (a) clear — provided in a manner that clearly communicates to each individual a message that the product or location contains a listed chemical and the nature of the health risk; and (b) reasonable — provided by a method reasonably calculated to reach the individual before exposure to the listed chemical. OEHHA’s Title 27 CCR regulations provide safe harbour warnings (both long-form and short-form) that, if followed exactly, are deemed to satisfy the clear and reasonable warning standard.

California Health & Safety Code §25249.6; Title 27 CCR §25600 et seq. (Article 6 — Clear and Reasonable Warnings); OEHHA guidance.

The ‘clear and reasonable’ standard gives businesses flexibility in how they provide warnings, but creates risk if custom warning language is used. OEHHA’s safe harbour warning regulations define specific warning content (including the new short-form requirements effective January 1, 2025), the warning symbol (yellow triangle with black exclamation mark), signal words, and transmission methods that create a legal presumption of compliance. Using non-compliant custom warnings creates litigation risk. Businesses should follow the Title 27 CCR safe harbour warning provisions precisely.