Using immersion test data to screen chemical protective clothing

A test to screen chemical protective materials in order to select potential candidates for further testing has been examined. The method involved determining the weight and volume changes in materials caused by immersion in the challenge chemical. Simple regression analysis showed that relatively short breakthrough times based on weight change and final thickness could be predicted with 90% confidence. Better results were obtained when discriminant analysis was used to classify breakthrough times greater than either 4 or 8 hr as a function of the weight change and final thickness. In 6% or less of the cases, actual breakthrough times were less than 4 or 8 hr when the predicted times were greater than these values. Discriminant analysis also was used to classify permeation rates as less than either 90 or 400 mg/m2-min based on weight change and initial thickness. In this case, actual permeation rates less than these were predicted to be greater in 4% and 7% of the cases, respectively.