Review of DOD's Approach to Deriving an Occupational Exposure Level for Trichloroethylene makes recommendations to improve the DoD's approach to developing an OEL for TCE, strengthen transparency of the process, and improve confidence in the final OEL value. This report reviews the DoD's approach using a literature review, evidence synthesis based on weight of evidence [WOE], point-of-departure derivation, physiologically based pharmacokinetic modeling, extrapolation tools, and explores other elements of the process of deriving an OEL for TCE. It examines scientific approaches to developing exposure values and cancer risk levels, defining the scope of the problem, and improving hazard identification.