Industrial hygiene study of the Johns-Manville mineral wool fiber facility, Alexandria, Indiana.
NIOSH 1975 Jan; :1-120
An industrial hygiene study was conducted at the Johns-Manville, Alexandria, Indiana, mineral wool fiber facility (SIC-3296) during April 11-15, 1975. Air samples were collected to evaluate time weighted average personnel exposures to respirable fibers, total airborne dust, free silica (7631869), trace metals and carbon- monoxide (630080). Spot noise measurements were also made. Results showed time-weighted-average fiber exposure to range from 0.10 to 1.95 fibers per cubic centimeter whereas time weighted average total airborne dust concentrations ranged from 0.85 to 28.55 milligrams per cubic meter with the free silica content of this dust ranging from 3.8 to 15.6 percent by weight. Twenty four of 45 calculated time weighted average free silica exposure values (total dust basis) were in excess of present OSHA standard for free silica. Exposure to carbon-monoxide and trace metals were found to be low. Most trace metal levels were below detection by atomic absorption spectroscopy. Airborne fiber diameter and length data were analyzed by fitting data to assumed log-normal size distribution functions. Count median airborne fiber diameters were found to range from 1.7 to 2.7 microns and count median fiber lengths were found to range from 6.8 to 24.8 microns. Airborne fiber diameter and length distributions determined by transmission electron microscopy were found to be in good agreement with the optical size data. Fiber diameter distributions and typical energy dispersive X-ray spectra for present and past fibers are presented and discussed in relation to past exposure levels. Recommendations for engineering and work practice improvements to reduce exposure levels also are made.
NIOSH-Publication; NIOSH-Survey; IWS-35-26; Field-Study; Region-5; Air-contamination; Airborne-particulates; Toxic-substances; Air-quality-control; Fibrous-dusts; Minerals; Insulation-materials; Dusts
NTIS Accession No.
NIOSH, Cincinnati, Ohio, 120 pages, 16 references