Industrial Hygiene Survey Report, Mineral Wool Plant, Bethlehem Mines Corporation, Bethlehem, Pennsylvania.
Worker exposures to respirable mineral wool fibers and airborne particulate matter were surveyed on December 9 to 11, 1976, at the Mineral Wool facility of the Bethlehem Mines Corporation (SIC-3296) in Bethlehem, Pennsylvania. The company employed approximately 45 workers. Preemployment and periodic medical examinations were provided, and safety glasses, shoes, helmets, hearing protectors and respirators were used. All fiber and particulate concentrations were below the recommended standards of 10 milligrams per cubic meter (mg/CuM) for total dust, 5mg/CuM for respirable dust, and 3 fibers per cubic centimeter greater than 10 microns in length and less than 3.5 microns in diameter. Observation of work processes used by cupola operators and assistants indicated that short term peak exposures to combustion by-products and metal fumes could be excessive. The author recommends mandatory use of respirators during tapping operations, and prohibition of the use of the compressed airline for removing dust from equipment.