Exposure of employees to manmade vitreous fibers: Installation of insulation materials

Worker exposure to manmade vitreous fibers during installation of insulation material was measured. Data were collected in a housing complex, a number of commercial and residential buildings under construction, and two aircraft insulation facilities. The average exposure of workers for all applications, except attic thermal insulation blowing operations and the aircraft insulation fabrication operations, was in the range of 0.01 to 0.05 fiber per milliliter. The average exposure of the blowing operations was in the range of 0.12 to 5.3 fibers per milliliter, and for the aircraft insulation fabrication operations the range was 0.02 to 0.56 fiber per milliliter. The fraction of airborne fibers less than 1 μm in diameter and longer than 5 μm in all applications except blowing operations and aircraft insulation fabrication was in the range of 5.7 to 38.5%; blowing operations were in the range of 20.5 to 54.8% and aircraft insulation fabrication operations were in the range of 33.9 to 90.7%. For the same three classifications, the respirable fraction of airborne fibers (diameters less than 3 μm ranged from 55 to 87%, 44 to 92%, and 94 to 99%, respectively.