Investigation on occupational hazards in a power lithium battery manufacturing enterprise

Objective To investigate the occupational hazards factors and exposure levels in a power lithium battery manufacturing enterprise, in order to evaluate the effectiveness of occupational prevention facilities, and to propose relevant control countermeasures.

Methods A comprehensive evaluation was conducted in this manufacture by using occupational health field investigation, environmental monitoring, occupational health examination, and engineering analysis methods.

Results The main occupational hazards in the enterprise were dust(carbon black, graphite, other dusts, welding fume), Nmethylpyrrolidone, metallic nickel and insoluble nickel compounds, manganese and its inorganic compounds, cobalt and its compounds, fluoride, hydrogen fluoride, ozone, nitrogen dioxide, butanone, noise, laser radiation, power frequency electric field, and high temperature environment. Among them, the ozone concentration at the laser welding position was higher than the national standard, with the highest concentration of 0.54 mg/m³, and this position was classified as grade Ⅱ(moderate hazard). The noise in the winding positions, shell entry positions, assembly spot welding, and liquid injection machine positions in the assembly workshop exceeds the national standard. In the assembly workshop, the noise at the winding, the assembly-spot welding, and the injection-machine positions were classified as grade Ⅰ(mild hazard), while the 8-hour equivalent sound level(L_{EX, 8 h}) at the shell entry position was high at 90.8 dB(A), and the operation was classified as grade Ⅱ(moderate hazard). The dust concentration, toxicant concentration, and noise level at the other positions were low and in compliance with the national standards. The occupational prevention facilities, emergency rescue facilities, personal protective equipment configuration, and occupational health monitoring of the enterprise basically met the relevant specification requirements.

Conclusions The enterprise is recognized as a project with serious occupational risk, and the positions where workers and exposed to ozone, hydrogen fluoride, and noise need to be paid attention to. It is still required to sustainably improve the occupational prevention facilities and emergency rescue facilities and strengthen individual protection.