Prop 65 and Product Packaging: A Buyer Overview for Imported Packaging (October 2026)

What Prop 65 is, in one paragraph

California’s Safe Drinking Water and Toxic Enforcement Act of 1986, known as Proposition 65, requires businesses to give a warning before knowingly exposing people in California to listed chemicals that cause cancer or reproductive harm. The list is maintained by the Office of Environmental Health Hazard Assessment (OEHHA) and is updated over time. Businesses with fewer than ten employees are exempt. Prop 65 does not ban chemicals and does not by itself require testing; it requires a warning when an exposure above the relevant level cannot be ruled out.

Where packaging chemicals can come into it

For most paper and board packaging, the question comes down to materials and components rather than the board itself. Chemicals on the Prop 65 list that buyers commonly ask about in packaging include lead (which can occur in some pigments, metal parts or recycled inputs), certain phthalates such as DEHP (associated with some flexible PVC), bisphenol A (BPA, associated with some coatings), PFOA and PFOS (historically linked to some grease-resistant treatments) and styrene (associated with polystyrene). Whether any of these are present depends on the exact materials your supplier uses, so ask rather than assume.

Look closely at components that are not paper: PVC or other plastic windows, foam and EVA inserts, magnets and metal hardware, ribbons, adhesives, inks, coatings and laminates.

Where a Prop 65 warning can go on packaging

Under OEHHA’s regulations, a “label” includes material printed on or affixed to the product or its immediate container or wrapper. So for a packaged consumer product, the warning is very often on the packaging. Common placements are a back or side panel of a folding carton, the back panel of a pouch, the back of a rigid box or its printed sleeve, or an applied sticker.

Design points from the safe-harbor rules (Title 27, California Code of Regulations, Article 6):

• Symbol. A black exclamation point in a yellow equilateral triangle with a bold black outline, placed to the left of the text. It may be printed in black and white if the label is not printed in yellow.
• Signal word. “WARNING:” in capitals and bold; since 2025 “CA WARNING:” or “CALIFORNIA WARNING:” are also accepted.
• Type size. The warning type must be no smaller than the largest type used for other consumer information on the product, and never smaller than 6-point.
• Languages. If the label gives consumer information in another language, such as Spanish, the warning must also appear in that language.
• Short-form change. OEHHA amendments that took effect on January 1, 2025 require short-form warnings to name at least one listed chemical. The older short-form wording remains acceptable for products manufactured and labelled before January 1, 2028.

If your packaging will be produced around that date, or held in inventory for a long time, agree with your adviser which wording to print now so that you do not have to sticker stock later.

Printed warning or applied sticker?

• Print it on the packaging when the same SKU is sold nationwide and your adviser has decided a warning is needed. It is neat and harder to remove.
• Use a sticker or label when only some SKUs, channels or batches need a warning, or when the wording may change. Make sure the sticker sits on a smooth, uncoated area so it stays on; see custom labels and stickers.
• Use a reserved panel when the decision is not yet made: leave a clear area on the dieline so a warning can be added without redesigning the pack.

Documents to request from a packaging factory

A packaging factory cannot decide whether you need a warning, but it can give you the evidence your adviser needs. BestPackFactory makes every product in its own factory, so material questions go to the people who source and convert the materials. Ask any supplier for:

1. A bill of materials for each item: board, film, inks, coatings, laminates, adhesives, inserts, windows, magnets and trims
2. Supplier declarations for inks, coatings and plastic components, where available
3. Third-party lab testing for the specific chemicals your adviser names, if you require it; scope, laboratory, cost and timing are confirmed in the quotation
4. Confirmation that the approved materials will not be substituted without your written approval
5. Batch or production records so a test report can be linked to the shipment it covers

For a wider document list, see the food packaging compliance document checklist.

Related California rules are separate

Prop 65 is not California’s only packaging-related law. Separate state rules address, for example, PFAS in plant-fibre food packaging and environmental marketing claims. Ask your adviser to review them alongside Prop 65 rather than assuming one answer covers all.

Common mistakes

• Assuming Prop 65 only applies to the product, not its packaging.
• Printing a warning in type smaller than other consumer information on the pack.
• Adding Spanish product copy but not a Spanish warning.
• Changing a component, such as a window film or insert, after testing was done.
• Asking the overseas factory to make the legal decision.

Before printing, run your warning panel through the packaging artwork checklist.

Official sources to check

• OEHHA: Proposition 65
• Proposition 65 warnings website (P65Warnings.ca.gov)

Rules and rates change. These pages are starting points; confirm the position that applies to your shipment with your customs broker or compliance adviser.

Related pages

• Custom labels and stickers
• Custom folding cartons
• Food packaging compliance document checklist
• Packaging artwork checklist
• Contact BestPackFactory