Maximum Allowable Dose Level (MADL)

A Maximum Allowable Dose Level (MADL) is the safe harbour level established by OEHHA for chemicals listed as reproductive toxicants under Proposition 65. Below the MADL, a business is not required to provide a Proposition 65 reproductive toxicant warning. The MADL is set at 1/1000 of the level shown to have no observable effect in the most sensitive reproductive endpoint study. Key MADLs include: lead: 0.5 μg/day; BPA: 3 μg/day; phthalates (DEHP): 8.7 μg/day; di-n-butyl phthalate (DBP): 8.7 μg/day; methanol: 47,000 μg/day. MADLs are published in Title 27 CCR §25805 and OEHHA’s Proposition 65 list (Excel version).

California Health & Safety Code §25249.10; Title 27 CCR §§25801–25809 (MADL methodology); §25805 (specific MADLs); OEHHA Proposition 65 list (Excel).

The MADL is the primary safe harbour threshold for reproductive toxicants. If a product exposure assessment demonstrates that the daily intake of a listed reproductive toxicant is below the MADL, no warning is required. Businesses should obtain MADL values from OEHHA’s published regulations and the Proposition 65 list spreadsheet. Note that many listed reproductive toxicants do not yet have established MADLs, in which case the business must affirmatively demonstrate through a risk assessment that exposure is below the level causing no observable effect divided by 1,000.