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HHE determination report no. HHE-79-45-649, The Timken Company, Canton, Ohio.

McQuilkin SD
Cincinnati, OH: U.S. Department of Health, Education, and Welfare, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, HHE 79-45-649, 1979 Dec; :1-13
Air samples were analyzed for the presence of crystalline-silica (7631869) (free silica), mineral wool fibers, and coal tar pitch volatiles (CTPV) at The Timken Company (SIC-2865), in Canton, Ohio on February 12 and 13, 1979 and May 21, 1979. An evaluation request came from the United Steelworkers of America, Local Number 1123, on behalf of the pithand workers engaged in mold cleanout and preparation activities at the stripper building. The quartz (14808607) concentrations of free silica in the air ranged from 123 to 286 micrograms per cubic meter which exceeded the OSHA respirable dust permissible exposure limit of 10 milligrams per cubic meter (mg/m3) of air divided by the percentage of quartz plus 2. The bulk refractory material used in the operation did not contain asbestos (1332214) or fibrous glass, but did contain a mineral wool fiber of monocalcium-silicate (37323903), which was identified as the probable cause of skin irritation reported in 12 confidential employee interviews. Analysis of the powdered CTPV indicated concentrations of benzene extractables of 0.03 to 0.118mg/m3, which were below the OSHA standard of 0.2mg/m3. The author concludes that at the survey time, pithand employees were exposed to hazardous concentrations of free silica, an inadequate respiratory protection program was in effect, and the CTPV mixture contained known and suspected carcinogens. They recommend implementation of engineering and administrative controls to reduce employee exposures to hazardous materials, particularly the installation of a negative pressure vacuum system for mold cleanout.
NIOSH-Author; Hazards-Confirmed; HHE-79-45-649; NIOSH-Health-Hazard-Evaluation; Iron-and-steel-foundries; Steel-workers; Air-sampling; Silica-dusts; Exposure-limits; Skin-irritants; Respiratory-protection; Control-measures; Unions; Region-5; Author Keywords: crystalline silica; free silica; mold cleanout
7631-86-9; 14808-60-7; 1332-21-4; 37323-90-3
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Field Studies; Health Hazard Evaluation
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National Institute for Occupational Safety and Health
Page last reviewed: December 11, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division