The manufacturing processes in chip industries are complex, and many kinds of raw materials and solvents of
different nature are used, most of which are highly toxic and dangerous. During the machine preventive
maintenance period, these toxic and harmful substances will escape from the sealed reaction chamber to the
clean workshop environment and endanger the health of the workers on-site, resulting in occupational
diseases. From the perspective of prevention, the spread and prediction of hydrochloric acid (HCl) that
escaped from the metal-etching chamber during maintenance were studied in this article. The computational
fluid dynamics technology was used for a three-dimensional numerical simulation of the indoor air velocity field
and the HCl concentration field, and the simulation results were then compared with the on-site monitoring
data to verify the correctness and feasibility. The occupational hazards and control measures were analyzed
based on the numerical simulation, and the optimal control measure was obtained. In this article, using the
method of ambient air to analyze the occupational exposure can provide a new idea to the field of occupational
health research in the integrated circuit industry and had theoretical and practical significance.