EPA RSL and VISL Calculators Went Offline in February 2026 - What to Do When EPA Tools Go Down

In February 2026, EPA’s Regional Screening Level (RSL) Calculator and the Vapor Intrusion Screening Level (VISL) Calculator both went offline without advance notice. The tools were restored in mid-March 2026, but for roughly a month, consultants and state agencies that rely on these calculators for site-specific screening level development were left without their primary tool.

This was not the first time EPA online tools have gone down, and it will not be the last. Here is what happened and what you can do to be prepared.

What Happened

Both calculators were taken offline by EPA in early February 2026. The EPA RSL website displayed a notice that the agency was working to restore the tools but provided no timeline. State agencies that depend on the calculators - including Wisconsin’s DNR, which uses the RSL Calculator to establish soil residual contaminant levels and the VISL Calculator for vapor action levels - published their own notices directing users to fall back on static tables and previously generated values.

The calculators came back online around March 16, 2026.

What Was Affected

The RSL Calculator generates site-specific screening levels using custom exposure parameters, target risk levels, and land use scenarios. It is the only EPA tool that produces screening levels for exposure pathways not included in the static generic tables (outdoor worker, indoor worker, construction worker, recreator, and fish ingestion pathways).

The VISL Calculator generates vapor intrusion screening levels for sub-slab soil gas and indoor air. Many state programs reference these values directly or use the calculator to derive state-specific values.

The static generic tables were NOT affected. The downloadable Excel and PDF tables on the RSL Generic Tables page remained available throughout the outage. These tables cover residential and commercial/industrial screening levels for soil, air, and tap water at the standard target risk and hazard quotient levels.

How to Keep Working When the Calculators Go Down

Download and Archive the Static Tables

Every time EPA publishes a new RSL update (typically May and November), download the full Excel workbook from the Generic Tables page and save it locally. The workbook contains all screening levels plus the underlying toxicity values and exposure parameters. If the website goes down, you still have the data.

We maintain the November 2024 RSL Summary Table in our QA files (890 chemicals, TR=1E-06, THQ=1.0).

Know Which Pathways Need the Calculator

The static tables cover residential soil, commercial/industrial soil, residential air, commercial/industrial air, and tap water. If your site assessment only needs these standard pathways, the static tables are sufficient and the calculator outage does not affect you.

You only need the calculator for non-standard pathways: outdoor worker soil, indoor worker soil, construction worker soil, recreator soil, recreator surface water, fish ingestion, and any scenario with custom exposure parameters.

Keep Your Own Spreadsheets

The RSL equations are published in the RSL User’s Guide. If you routinely need site-specific screening levels, build your own spreadsheet implementing the relevant equations with the current toxicity values and default exposure parameters. This gives you independence from EPA’s web infrastructure and lets you modify parameters as needed.

Many experienced risk assessors already maintain their own calculation spreadsheets and use the EPA calculator primarily as a QC check.

Check State Resources

Some state programs maintain their own screening level tables or calculators that are independent of EPA’s tools. For Ohio, the VAP uses CIDARS standards rather than EPA RSLs, so VAP work was unaffected by the calculator outage.

The Broader Lesson

Federal environmental tools going offline is not a rare event. The EPA ECHO database, Envirofacts, NEPAssist, and various SDWA tools have all experienced outages over the years. Budget uncertainties, IT infrastructure changes, and administration transitions all contribute to reliability issues.

The consultants who handle these disruptions smoothly are the ones who maintain local copies of critical reference data. Download the tables, archive the PDFs, save the guidance documents. If the only place you can access a number is a government website, you are one server outage away from a dead stop on your project.

For a detailed explanation of how RSLs work, what the tables contain, and which table to use, see our EPA Regional Screening Levels Explained guide.