Proposition 65 No Significant Risk Levels (NSRLs) and Maximum Allowable Dose Levels (MADLs)
Safe harbor levels, which include No Significant Risk Levels (NSRLs) for cancer-causing chemicals and Maximum Allowable Dose Levels (MADLs) for chemicals causing reproductive toxicity, have been established for many of the chemicals listed under Proposition 65. Exposure levels and discharges to drinking water sources that are below the safe harbor levels are exempt from the requirements of Proposition 65. In some instances, enforcement actions may have resulted in negotiated exposure levels relative to specific settlement agreements. Please visit the Attorney General's Proposition 65 web site at https://oag.ca.gov/prop65 for further information about specific enforcement actions.
Below is a list of NSRLs and MADLs established in regulation in Title 27, Cal. Code of Regulations, Sections 25705, 25709 and 25805. These safe harbor levels do not preclude the use of alternative levels that can be demonstrated by their users as being scientifically valid. A hyperlink is provided for those NSRLs or MADLs for which the documentation of their derivation is electronically available.
OEHHA has also prioritized certain chemicals for NSRL development.
You can download the entire list of NSRLs and MADLs as an excel file using the export button below.
Safe Harbor List
Note:Opening this file will require you to click “yes” to continue.
a Where a source or product results in exposures by multiple routes, the total exposure must be considered. For example, the MADL for benzene is exceeded when the absorbed dose exceeds 24 μg/day. If only inhalation and oral exposure occurs, the benzene MADL is exceeded when: (oral dose ÷ 24 μg/day) + (inhalation dose ÷ 49 μg/day) > 1.0.
b Levels for male children and adolescents were calculated by application of the default bodyweights specified in Section 25703(a)(8) to the procedure specified in Sections 25801 and 25803, Title 27, California Code of Regulations.
c Level represents absorbed dose (rounded from 6,525 μg/day). Since 100% of ingested toluene is absorbed, oral dose is equivalent to administered dose. It is assumed that roughly 50% of the dose administered by the inhalation route is absorbed. Therefore the MADL for inhaled toluene is 13,000 μg/day (rounded from 13,050 μg/day ), corresponding to an absorbed dose of 6,525 μg/day.
d Fibers equal to or greater than 5 micrometers in length and 0.3 micrometers in width, with a length to width ratio of greater than or equal to 3:1 as measured by phase contrast microscopy.