Effective controls for air contaminants of compounding dusts and rubber (9006046) fumes were evaluated at the Firestone Tire and Rubber Company facility (SIC-3011) in Wilson, North Carolina on March 17 to 23, 1980. Air samples were collected and ventilation data, engineering designs, and work practices were examined. Systems covered included the hopper bin hood, semi-automated compounding system, mixer charging area, under stock cementer hood, calendering, ventilation system, curing press row hood air system, and cement house ventilation system. The ability of the semi- automated compounding system to capture dust generated from free falling materials during bagging was inadequate and was hampered by cross drafts in the compounding room. Dust contamination in the hopper bin area was mostly due to careless work practices during bag slit, bin filling, and bag disposal operations. Although dusts generated by dispersion from the conveyor, machinery, and structures and by empty bag handling and disposal were not controlled by the hood in the mixer area, worker exposure was avoided by prompt and proper work practices. There were some inefficiencies in maintenance of the over all hood airflow which was 40 percent less than the specified capacity of the fan. Work practices associated with the hood were insufficient. The mill hoods in the under stock cement area showed a low face velocity. The low velocity along with the open nature of the hoods made the hoods vulnerable to air drafts. Fumes generated by rubber on the lower calendar rollers were not captured by the ventilation system. These fumes were regarded as the source of the particulates found in the air samples. No major problems were encountered in the curing areas. In the cement house, the exhaust air system was not effective and little air movement was noted especially in potential solvent spill areas. Housekeeping in this area required improvement and spills were noted throughout the area. The particulate concentrations obtained in the various areas were below the specified 8 hour time weighted averages.
Division of Physical Sciences and Engineering, NIOSH, Cincinnati, Ohio, 124 pages, 9 references