Airborne fiber exposure assessment of dry asbestos-containing gaskets and packings found in intact industrial and maritime fittings.
This study assessed airborne fiber exposures from intact asbestos-containing gaskets and packings while activities representative of historical work practices were performed. The study design eliminated analytical interferences while systematically capturing information related to activity variables. A series of gasket and packing activities was conducted according to traditional methods while sampling was performed to determine the 8-hour time-weighted average (TWA). The fittings used during this study were obtained intact from a decommissioned industrial power plant and U.S. Navy destroyers. The activities tested included flat blade scraping, hand wire brushing, power wire brushing, making gaskets with a ball-peen hammer, and stem packing removal and replacement. All activities were performed dry. Results for every area and personal sample showed the 8-hour TWAs were well below the current Occupational Safety and Health Administration permissible exposure limit of 0.1 f/cc. A database of more than 400 points was developed to analyze information from variable factors related to the tests. These factors included, for example, type of gasket, composition of the gasket, percentage of gasket adhering to a flange surface, gasket surface area, and minutes elapsed for removal. The results demonstrate a very low rate of fiber exposure from routine activities associated with asbestos-containing elastomeric gaskets and impregnated packing.
Boelter
Fred W
FW
Boelter & Yates, Inc., 1300 West Higgins Road, Park Ridge, IL 60068-5772, USA.
Crawford
Gary N
GN
Podraza
Daniel M
DM
D000395:Air Pollutants, Occupational / Q000032:analysis*; D001194:Asbestos / Q000032:analysis*; D006801:Humans; D008452:Maximum Allowable Concentration; D008669:Metallurgy; D008855:Microscopy, Electron, Scanning; D016273:Occupational Exposure / Q000032:analysis*; D014481:United States; D014489:United States Occupational Safety and Health Administration
D000395:Air Pollutants, Occupational; D001194:Asbestos