Respirator Filters In Protection Against Low-Boiling Compounds.
NIOSH 1980 Sep:125-138
The efficiency of four European respirator filters containing activated charcoal in the removal of methanol (67561) was investigated. The four medium capacity filters, which had carbon contents ranging from 112 to 176 grams dry weight, were subjected to sorption tests to determine breakthrough times and filter capacities and to desorption tests to determine the concentration of methanol in effluent air when partly used filters were reused at a later time. The wide variation in the breakthrough times of the four filter types resulted from differences in the amounts of charcoal and differences in the activity levels of the charcoals in the filters. Dose concentrations had only a small effect on the effluent methanol concentration during desorption tests. Desorption at 25 degrees C resulted in a somewhat higher effluent concentration than did desorption at 20 degrees C. The author concludes that if the type I filter is used under working conditions where it is loaded with 600 milligrams of methanol and later reused in a clean atmosphere, the maximum concentration of desorbed methanol in the effluent air will be in the range of the threshold limit value.
Filter-materials; Filtration; Materials-testing; Respiratory-protection; Respiratory-protective-equipment; Personal-protective-equipment;
Control Technology and Personal Protective Equipment; Research Tools and Approaches;
Papers from the NIOSH International Respirator Research Workshop, September 9-11, 1980, Division of Safety Research, NIOSH, Morgantown, WV