Database maintenance and updates
The Health-Based Screening Level (HBSL) database is maintained by the USGS and the Department of Environmental and Biomolecular Systems at the Oregon Health & Science University. Approximately monthly, the five U.S. Environmental Protection Agency (USEPA) data sources are reviewed for any updates to cancer classifications or toxicity values. Any updated information is entered into the database and evaluated to determine whether the updates affect HBSL calculations. All new database entries or revisions resulting from the monthly review are subjected to a quality-control process. When the database is searched, the data output for HBSL values or USEPA toxicity information will include the date of the most recent database update.