Change in permeation rates of acids and bases through limited use protective fabrics after repeated wash cycles

The primary objective of this study was to determine if there is a change in permeation rates when limited use protective fabrics undergo repeated exposure and wash cycles. The null hypothesis of this study was that no substantial change in permeation takes place after the test material is subjected to repeated contact with a strong acid or base and has undergone repeated wash cycles. ^ The materials tested were DuPont Tychem® CPF 3 and CPF 4 fabrics. The challenge chemicals in this study were ninety-eight percent sulfuric acid and fifty percent sodium hydroxide. Permeation testing was conducted utilizing ASTM designation F739-99a Standard Test Method for Resistance of Protective Clothing Materials to Permeation by Liquids or Gases Under Conditions of Continuous Contact. ^ In this study, no change in permeation rates of either challenge chemical was detected for CPF 3 or CPF 4 limited use protective fabrics after repeated exposure and wash cycles. Certain unexposed areas of the fabric suffered structural degradation unrelated to exposure and which may be due to multiple washings.^