Assessment of Current Fibre and Silica Exposure in the U.S. Refractory Ceramic Fibre Manufacturing Industry

An industry-wide study was initiated in 1987 to characterize current exposures to refractory ceramic fibres (RCF) and silica in the major RCF manufacturing facilities located in the United States. Samples are collected quarterly using NIOSH methods; for fibre sampling, the method incorporates a nickel-plated aluminium (conductive) cowl. The results reported are from the initial and first two rounds of quarterly monitoring. Cristobalite and quartz were detected in five of the 35 samples for silica. TWA fibre counts ranged from below the limit of detection (0.01 fibres ml⁻¹) to 1.04 fibres ml⁻¹. TWA fibre counts from cowl rinses ranged from below the limit of detection to 1.54 fibres ml⁻¹. Additional sample collection will provide data for the study of variability in exposure. Fibre sizing studies of both the air sampling and cowl rinse filters have been initiated.