Updates to USEPA Regional Screening Levels

USEPA Updates Regional Screening Levels

The United States Environmental Protection Agency (USEPA) Regional Screening Levels (RSLs) were updated recently, effective May 18th, which may impact cleanup and closure of certain contaminated sites. Significantly, the USEPA’s most recent update added an Oral Cancer Slope Factor (CSF) for naphthalene, as well as other adjustments. The USEPA updates tables supporting the derivation of RSLs twice per year. RSLs are risk-based levels incorporating the USEPA’s exposure assumptions, toxicity information, and risk equations. RSLs (and their supporting assumptions) are an important tool for initial site screening at Superfund sites and for various state agencies. Screening levels can be obtained in generic summary tables, or by using the RSL calculator to model more specific site use utilizing user-defined and default input variables.

For more information about how to use RSLs, or potential impacts of updates, please visit the USEPA’s website or contact us below: