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Environmental and materials

California Proposition 65

California law that requires a clear warning when a product exposes users to chemicals on the state list above safe harbour levels.

CodeProp 65
RegionCalifornia, United States
TypeMandatory if exposure triggers
Issued byCalifornia Office of Environmental Health Hazard Assessment
Last verified2026-10-10
Quick answerCertification · last verified 2026-10-10

California law that requires a clear warning when a product exposes users to chemicals on the state list above safe harbour levels. Status: Mandatory if exposure triggers. Issued or recognised by California Office of Environmental Health Hazard Assessment.

CodeProp 65
RegionCalifornia, United States
TypeMandatory if exposure triggers
Issued byCalifornia Office of Environmental Health Hazard Assessment
GroupEnvironmental and materials
Last verified2026-10-10
How to cite this pageIoT Atlas. "California Proposition 65". https://hi-spark.net/certification/prop65.html Last verified 2026-10-10.

What it means

The rule is warning-based rather than approval-based. Manufacturers either assess exposure and warn, or document that exposure is below the safe harbour level. Warning content and placement follow set formats.

Applies to

  • Consumer products sold in California
  • Cables, vinyl materials, solder and coatings
  • Products where a chemical may be released during normal use

What it does not cover

  • Federal chemical restrictions
  • EU substance rules
  • Product safety certification

Verification checklist

  • Screen the bill of materials against the current chemical list
  • Assess likely exposure routes and duration of use
  • Choose between a warning and a documented no-exposure case
  • Apply the warning in the required format and refresh the review

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