In a five-year program performed with the EPA Office of Research and Development, the Chemical Engineering Branch (CEB) of the EPA Office of Toxic Substances has developed state-of-the-art tools for assessing the effectiveness of rubber and plastic protective clothing materials as barriers to chemicals. These tools were developed for use by CEB to conduct more thorough assessments of the potential for occupational exposures to new chemicals as required in the Premanufacture Notification (PMN) review process. The tools include: a computerized model for predicting the permeation of chemicals through common clothing materials using Fickian diffusion theory and the physical property data typically available from a PMN submission; guidelines for specifying permeation testing and interpreting the results of such tests, including development of a new, intermittent chemical contact permeation test method; and a manual that guides the assessment of protective clothing permeation on the basis of published data, data from CEB-prescribed testing, and the output of the predictive model. The report describes the development of these tools and lists the products delivered under the project from October 1985 through September 1990. By applying these tools, CEB can perform more thorough and efficient PMN reviews and identify other areas that require improvement in their assessments of chemical protective clothing performance.