Collections > Master's Papers > Gillings School of Public Health > Respirable Dust Levels During Relining of Foundry Induction Furnaces

Industrial hygiene surveys were conducted to assess employee exposures to respirable silica during induction furnace relining. The operation is performed once every 6 to 12 weeks and takes between 8 to 16 hours to complete. Survey results showed that exposures ranged between 0.87 - 19.90 mg/m3 during the process and samples contained between 40 - 65% free silica as determined by colorimetric method of analysis. The exposures which occur during the initial lining removal stage include exposures to cristobalite which is formed during furnace use. The health implications of these short-term, high exposures has not been evaluated, however, good industrial hygiene work practices suggest that exposure levels be kept to a minimum and recommendations for dust reduction have been made. Other potential hazards identified were noise created by pneumatic tools and asbestos present in the preliner fabric. Both require further evaluation to determine the extent of the exposures.