California Office of Environmental Health Hazard Assessment (OEHHA)

United States — California · Binding — Proposition 65 warning law (listings + MADL/NSRL) · Established 1991 · Authored by Karen Pendergrass, Institute of Contaminant Standards · oehha.ca.gov

Quick read

California’s Office of Environmental Health Hazard Assessment runs the science behind Proposition 65, which requires a warning before exposing Californians to listed chemicals — including lead, cadmium, and inorganic arsenic. For some it sets a Maximum Allowable Dose Level (MADL, for reproductive toxicants) or No Significant Risk Level (NSRL, for carcinogens); exposures below these are exempt from the warning requirement. Prop 65 is enforceable law, but it works through warnings and exposure thresholds, not food concentration limits.

Mandate & scope

OEHHA administers the scientific side of California’s Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65). It maintains the list of chemicals known to the state to cause cancer or reproductive harm — lead, cadmium, inorganic arsenic, nickel, and hexavalent chromium compounds are all listed — and derives the exposure levels below which a business is exempt from the warning requirement: No Significant Risk Levels for carcinogens and Maximum Allowable Dose Levels for reproductive toxicants (lead’s MADL of 0.5 µg/day is among the most stringent heavy-metal exposure thresholds anywhere; cadmium’s oral MADL is 4.1 µg/day). Prop 65 is enforced through litigation, including by private plaintiffs, which makes it commercially consequential out of proportion to California’s size. It governs exposure and warnings rather than setting a maximum concentration a food may contain.

Positions across metals

Where it diverges

Prop 65 MADLs and NSRLs are daily-exposure thresholds (µg/day) — a different basis again from intake-per-body-weight guidance and from food concentration limits — so they are not directly comparable with EFSA, JECFA, EU, or FDA values. Their significance is legal rather than a matter of toxicological consensus: lead’s 0.5 µg/day MADL sits far below the intake implied by most other bodies’ values and drives the warning labels and settlements that shape product reformulation across the US market. The question Prop 65 asks is not “is this number lower than EFSA’s” but “does exposure exceed the level that triggers a mandatory warning.”

Lead

Cadmium

Inorganic arsenic

Nickel

Hexavalent chromium

Update log

Key documents

References

Positions, the update log, and key documents above are generated from the per-instrument regulation pages this body issues, via tools/build-regulator-pages.mjs. The wiki reports what OEHHA has published; it does not endorse it. See the wiki/HMTc separation policy for why reporting regulatory values is kept architecturally separate from certification threshold-setting.

Update history

This page has no substantive edit history yet. Future revisions will be recorded here once the change lands in git.