Abstract
Testing the permeation resistance of protective clothing materials against chemical gases and vapors requires attention to additional factors over conventional material permeation testing with liquids. Permeation testing factors relevant to gas and vapor challenges are described, and results for testing various material-gas combinations are reported. Challenging protective clothing materials with gases presents a series of special problems including gas delivery, cell integrity, sufficient analytical detection, and disposal. The concentration and other properties of gases and vapors are very sensitive to small changes in temperature and pressure. The method of delivering gases or vapors to the test cell must provide for careful regulation of these variables and maintain homogeneous contact of the chemical with the material over the test period. While many organic vapors are easily and directly detectable by gas chromatographic methods, several gases require special collection media and analytical procedures to achieve detection limits below 1 ppm. Handling of exhaust gas from the challenge chamber of the test cell must reflect safe laboratory practices without creating unnecessary chemical waste. Recommended procedures and results are presented for the six new gases added to ASTM Standard Guide F1001, Selection of Chemical Liquids and Gases to Evaluate Protective Clothing Materials, as well as for other difficult test gases used in evaluating protective clothing materials.