Performance of chemical cartridge, half-mask respirators under working conditions in a copper smelter.
NIOSH 1975 Sep; :1-33 pages
Three chemical cartridge half mask respirators were tested for protection against sulfur-dioxide (7446095) (SO2) exposures during copper smelter work. Six furnace feeder workers and three members of the study team wore the respirators during furnace charging operations. SO2 concentrations inside and outside the respirator were measured using a specially designed personal monitor. Average exterior and interior mask SO2 concentrations were 55 and 5 milligrams per cubic meter, respectively. Median protection factors were 15.29 for the Welch 7500-11 mask, 13.72 for the American Optical R-8153 mask, and 9.59 for the Mine Safety Appliance (MSA) Comfo II 459434 mask. Six of the nine men rated the Welsh mask as more comfortable than the MSA mask, while seven rated the American Optical mask as more comfortable than the MSA mask. Protection factors for the masks increased with exterior SO2 concentrations. Overall performance of all three masks was judged as poor based on the high percentage of tests with protection factors less than 10. The authors suggest that the poor performance of the masks could have been due to respirator strap tension, facial hair on the subjects or normal work activities. They suggest additional tests with other types of respirators, development of a testing program, investigation of the relationship between ambient SO2 concentration and mask protection factor, and training of worker's in proper respirator usage.
NIOSH-Contract; Contract-099-74-0005; Respiratory-protective-equipment; Personal-protective-equipment; Chemical-cartridge-respirators; Smelters
Final Contract Report
NTIS Accession No.
Division of Environmental and Occupational Health, University of Utah Medical Center, Salt Lake City, Utah