Authoritative Risk Assessment - Information from U.S. Government Agencies

The Environmental Protection Agency (EPA) and the Centers for Disease Control (CDC) Agency for Toxic Substances and Disease Registry (ATSDR) have performed extensive risk assessments more recently than OSHA for many of the chemicals regulated by OSHA in the occupational environment, including toluene.

The EPA Integrated Risk Information System (IRIS) Reference Concentration (RfC) for toluene is 5 mg/m³ (published in 2005).

• The RfC for toluene was derived from a series of 10 studies observing neurological effects in workers.
• The toxicological review provides information on which these values are based.

The CDC Agency for Toxic Substances and Disease Registry (ATSDR) established an Acute Minimal Risk Level (MRL) of 2 ppm and a Chronic MRL of 1 ppm in 2017.

• The acute MRL applies to exposure from 1-14 days, a chronic MRL applies to exposures greater than 1 year. The MRL's would have to be adjusted to a higher value to be applied in an occupational environment.
• The chronic MRL was derived from a series of studies showing adverse effects on neurological function as shown by impaired color vision in workers exposed to toluene.
• For additional information on MRL's refer to the Minimal Risk Levels (MRLs) List.
• The ATSDR Toxicological Profile for toluene is a unique compilation of toxicological information on toluene. The profile reflects a comprehensive and extensive evaluation, summary, and interpretation of available toxicologic and epidemiologic information on toluene.