The permeation resistance of thin polyester films and metallized, low-density polyethylene (LDPE) films was evaluated to assess their feasibility for use in chemical protective clothing applications. For a 0.002 cm polyester film, permeation tests were conducted with acetone, carbon disulfide, dichloromethane, and tetrahydrofuran. In all cases no permeation was detected for a five hour duration at the sensitivity of the permeation method. Concentrated sulfuric acid, however, severely degraded the polyester film. Permeation tests were also conducted with a series of 0.0033 and 0.0071 cm LDPE, metallized-LDPE films, and their laminates to study the contribution of the metal layer to the barrier properties. Tests with dichloromethane were performed on the films and laminates as is and also after flexing. In all cases, the dichloromethane permeation rates were lower through the metallized-LDPE films than through the LDPE substrate alone when tested without flexing. The permeation rates through the metallized-LDPE films following flexing, however, were similar to those measured for the LDPE substrate. (Copyright (c) 1990 Technomic Publishing Co., Inc.)