Objective To evaluate the effectiveness of control measures implemented to rectify indium-related occupational hazards in a sputtering target manufacturing enterprise.

Methods Occupational investigation, including field audit and testing, and occupational health examination methods were employed to assess the control effectiveness two years after the implementation of comprehensive rectification measures in a sputtering target manufacturing enterprise in southern Jiangsu in 2022. The measures included installing physical barriers/isolations, adding an upgraded dust collection and recirculation system with top-supply and bottom-exhaust ventilation, providing powered air-purifying respirators, establishing dedicated locker rooms and shower facilities for indium-related operations, and posting warning labels for indium and its compound dusts.

Results After implementing the comprehensive occupational hazard control measures, the concentrations of indium and its compounds in the air of the bonding workshop were reduced. The median time-weighted average concentration M (P₂₅, P₇₅) decreased from 0.087(0.033, 0.139) mg/m³ before rectification to 0.061(0.041, 0.066) mg/m³ after rectification. The non-parametric Mann-Whitney U test showed that the concentrations of indium and its compounds between bonding stations 1 and 2, as well as between stations 7 and 8, were significantly lower after rectification (both P < 0.05). The mean serum indium level among indium-exposed workers decreased significantly from (9.60 ± 4.45) μg/L before rectification to (2.56 ± 0.98) μg/L after rectification (P < 0.01). The differences were all statistically significant.

Conclusions This sputtering target manufacturing enterprise in southern Jiangsu achieved notable results in controlling indium-related occupational hazards through optimized workplace layout, enhanced engineering controls, upgraded personal protective equipment, and improved occupational health surveillance.