Preliminary results of permeation studies of chemical protective garments were summarized. The studies were recently completed by the Los Alamos National Laboratory under the direction of NIOSH. Chemical permeation was measured for epichlorohydrin (106898), perchloroethylene (127184), trichloroethylene (79016), 1,2- dibromoethane (106934), Aroclor-1254 (27323188), and solutions of Aroclor-1254 in trichlorobenzene and paraffin-oil. Materials tested included surgical rubber, butyl-rubber, polyethylene, polyvinyl- alcohol, Saranex laminated Tyvek, Neoprene, milled Nitrile, Viton, Viton-SF, Vitrile, and flexed Teflon. Thicknesses ranged from 0.003 to 0.046 centimeters. Breakthrough times of the chemicals through the tested materials were tabulated. Vitrile and Teflon were consistently resistant to permeation by the four solvents, having breakthrough times greater than 60 minutes. Surgical rubber and polyethylene were readily penetrated by the solvents, with breakthrough times of less than 30 minutes. Nitrile, Vitrile, Viton, and Viton-SF were resistant to permeation by Aroclor-1254 and the Aroclor solutions, showing breakthrough times of greater than 8 hours. Polyvinyl-alcohol and surgical rubber were the least resistant to pure and dissolved Aroclor-1254, showing breakthrough times of less than 3 hours. The authors point out that factors other than chemical permeation are important in the selection of proper protective clothing.