Vapor Screening Level (VSL)
Abstract
The U.S. Centers for Disease Control and Prevention (CDC), the U.S. Environmental Protection Agency, and the National Research Council give health protection guidance to the U.S. Army Chemical Materials Agency (CMA) as it executes its mission of safely storing and destroying the nation's aging chemical weapons. By using advanced monitoring systems placed in and around storage and disposal areas, CMA ensures the air is safe for workers and the public. The airborne exposure limit (AEL) is a guideline developed by the CDC to determine how long people can be exposed to potential pollutants in the air without resulting effects to their health. AELs are based on a short-term exposure limit (STEL) for acute worker exposure, a worker population limit (WPL) for long-term worker exposure, and the general population limit (GPL) for the public. The GPL is the concentration that the unprotected general population can be exposed to 24 hours a day, 7 days a week, for a long period of time without experiencing any adverse health effects. The WPL is the concentration a worker can be exposed to for an average 8-hour work day. The STEL defines the concentration of contamination in the air that an unprotected worker may be safely exposed to for up to four 15-minute periods spaced at least an hour apart in an 8-hour workday. The STEL level concentration also is useful in monitoring secondary waste generated by destroying chemical weapons. These wastes include items such as personal protective equipment, insulation, cleaning materials, and other solid waste materials. CMA adapted the STEL level vapor concentration to screen for agent-exposed waste material. The adapted STEL is called the Vapor Screening Level (VSL). It is the same vapor concentration as the STEL, but unlike a STEL, a VSL is determined from air sampled typically about 5 minutes. VSLs are used to supplement the STEL to protect workers' health during plant operations as waste is generated and moved to storage areas.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 20, 2007
- Accession Number
- ADA476397