The U.S. Environmental Protection Agency recently updated the file for Naphthalene on its Integrated Risk Information System (IRIS). Users are encouraged to access IRIS directly for the specific values and documentation.

The new toxicity values (Reference Dose and Reference Concentration) were incorporated into the Method 1 standards of the Massachusetts Contingency Plan (310 CMR 40.0000) during the 1999 revisions.

Any Method 3 Risk Characterizations conducted subsequent to September 17, 1998 should include the new toxicity data for naphthalene.