United States (California)

Compliance · Nº 12 · United States (California)

Prop 65

California Proposition 65 warnings

Applies to — Products sold into California

California Proposition 65 (the Safe Drinking Water and Toxic Enforcement Act of 1986), administered by OEHHA, requires a “clear and reasonable warning” before knowingly exposing California residents to any of 900+ listed chemicals known to cause cancer, birth defects, or reproductive harm. The warning is often a label. The list and warning rules change over time — the short-form warning regulation has a compliance deadline of January 1, 2028.

What it is

Proposition 65 is a California right-to-know law, administered by the state’s OEHHA. It requires businesses to provide a “clear and reasonable warning” before knowingly exposing California residents to a listed chemical — over 900 substances known to cause cancer, birth defects, or reproductive harm. For many products the warning appears on the label.

Why it matters to a label buyer

If your product could expose a Californian to a listed chemical above the relevant threshold, a Prop 65 warning may be required — and that warning is frequently printed on the product label or packaging. It is a moving target: the list is updated (for example Bisphenol S was listed in December 2025, creating obligations by December 2026), and the short-form warning regulation has a compliance deadline of January 1, 2028.

How to approach it

Determine whether Prop 65 applies to your specific product and exposure scenario — this depends on the chemicals present and the exposure level, and is a legal determination best confirmed with a qualified advisor. If a warning is required, design the label to carry the correct current warning text and keep it updated as the rules change.

Common questions

Answered
straight.

What is a Proposition 65 warning?

A "clear and reasonable warning" California requires before exposing residents to any of 900+ listed chemicals known to cause cancer, birth defects or reproductive harm. It is administered by OEHHA and is often printed on the product label.

Do I need a Prop 65 warning on my product?

It depends on whether your product exposes a Californian to a listed chemical above the relevant threshold — a determination best confirmed with a qualified advisor. Note the rules change: the short-form warning regulation has a January 1, 2028 compliance deadline.

General guidance — not legal advice

This is a plain-English overview to help you ask the right questions — not a legal opinion or a compliance certification. Requirements change and depend on your specific product, market, and packaging. Always confirm with your supplier’s compliance documents and, where it matters, a qualified regulatory advisor.

Official source · OEHHA — Proposition 65 ↗

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