Abstract
Background information concerning reasons for the initiation of this study, the tentative threshold limit of 0.2 mg per cubic meter of air (ACGIH), and previous attempts at sampling with glass fiber filters are discussed. Problems encountered in obtaining consistent results with glass fiber filters and the benzene extraction analysis technique led to a search for a better technique. Comparison of glass fiber filters, cellulose acetate membranes, cellulose filters, and cellulose thimbles with the silver membranes were made. This comparison included weight stability with humidity changes and benzene extraction and airflow determinations. The results of actual sampling are listed, and other possible uses of the metal membrane in industrial hygiene are discussed.
A method is presented for collecting and analyzing samples for coal tar pitch volatiles by using a silver metal membrane filter and benzene extraction. The collection of a 1-cubic-meter air sample and the use of a five-place analytical balance accurate to 0.01 mg provides adequate sensitivity to detect 0.10 mg of coal tar pitch volatiles per cubic meter of air.