EPA developed a spreadsheet calculator, the Vapor Intrusion Screening Level (VISL) Calculator (XLSM)(14 pp, 1 MB)  and Vapor Intrusion Screening Levels (VISL) User's Guide that:

• lists chemicals considered to be volatile and sufficiently toxic through the inhalation pathway; and
• provides VISLs for groundwater, soil gas and indoor air, which are generally recommended, media-specific, risk-based screening-level concentrations.

The primary purpose of the VISL calculator is to assist Superfund site managers and risk assessors in determining, based on an initial comparison of site data against the VISLs: whether chemicals found in groundwater or soil gas can pose a significant risk through vapor intrusion; and, if so, whether a site-specific vapor intrusion investigation is warranted.

Other Agency cleanup programs may also find it helpful to consider the VISLs for their own specific needs.