The US Department of Defense should overhaul its process for establishing a workplace exposure limit for the chlorinated solvent trichloroethylene (TCE), a Nov. 15 report by a National Academies of Sciences, Engineering, and Medicine committee says. The report questions why the DOD did not follow best practices in its hazard assessment and review of published studies on the health effects of TCE.
Deviating from best practices “puts the agency in a position of having to develop, document, and defend a different approach, which is particularly difficult when applied to a chemical with a large and controversial database, such as TCE,” the report states.
TCE is a human carcinogen and has adverse effects on the liver, kidneys, brain, and immune system, as well as on reproduction. The DOD is concerned about people inhaling TCE while working in facilities near contaminated DOD sites.
The US military once widely used TCE as a metal degreaser and in maintenance of tanks and aircraft. The chemical now contaminates the soil and groundwater at numerous DOD sites and can migrate into the air of buildings near such sites.
The National Academies committee agrees with the DOD that current TCE exposure limits for workers may be inadequate for DOD workers because of the potential for exposure to vapors from contaminated sites. The panel suggests that the DOD use its proposed limit of 0.9 ppm—lower than any other federal limit for TCE—while the agency works on revamping its approach.