Risk Assessment of Welders Exposure to the Released Contaminated Gases in Different Types of Welding Processes in a Steel Industry

Abstract

Background: Exposure to the evaporated gases during the welding process has short- or long-term effects on welders’ health. Assessment of the risk by identifying and determining the chemical risk rating might be a useful tool for the experts in industrial hygiene. Objectives: The present study aimed at evaluating the exposure of welders to welding gases in seven welding types in the Steel Industry. Methods: The present study was conducted in one of the factories of the steel industry in 2017. Seven types of welding were studied including SMAW-E7018, SMAW-E730, MIG, MAG, PAW, SAW, and GTAW. Sampling from the NO, NO2, CO, CO2, and O3 was done via direct-reading instruments. To assess the health risk of exposure, the used approach was the one proposed by the division of occupational safety and health of the labor department of Singapore. Results: Findings of the present study revealed that the average range of welders’ exposure to NO, NO2, CO, CO2, and O3 gases in various welding processes was 30 - 50, 2456 - 5000, 2 - 12, 3.5 - 6, and 0.16 - 0.5 parts per million (ppm). Maximum and minimum concentrations of exposure to each of the gases were observed in MIG and PAW welding processes, respectively. The results of risk assessment showed that ozone and nitrogen dioxide had a very high-risk rating and nitrogen monoxide had a rank of “negligible” in all types of welding. Among the different types of welding, the most and the least risks of welding types were in MIG and PAW welding, respectively. Conclusions: MIG welders have a high occupational exposure to various types of welding gases. Use of control measures such as installing a local ventilation system, workplace air monitoring, implementing appropriate respiratory protection, and training the workers are recommended for safety of the welders.