Abstract:

Objective To analyze the characteristics，causes，and risk factors of occupational chronic n-hexane poisoning incidents，and provide a basis for prevention strategies. Methods A retrospective study was conducted on enterprises and patients involved in chronic n-hexane poisoning incidents that occurred in a city in Guangdong Province from 2023 to 2024. Data from on-site occupational health surveys，workplace n-hexane concentration measurements，and clinical and diagnostic records were collected to analyze the causes of occupational chemical poisoning resulting from n-hexane exposure. Results All three incidents occurred in small enterprises using n-hexane-containing solvents for cleaning and wiping operations，resulting in poisoning of 7 employees. Occupational hygiene investigations showed that incident A workstations had short-term exposure concentration（C_STE） of 806.1-1 023.3 mg/m³，exceeding the limit by a factor of 5.7；Incident B workstations had exposure concentration of time weighted average（C_TWA） of 0.8-712.0 mg/m³，exceeding the limit by a factor of 7.1，and C_STE of 1.4-1 007.4 mg/m³，exceeding the limit by a factor of 5.6；Incident C workstations had C_TWA of 34.9-89.7 mg/m³ and C_STE of 44.2-520.7 mg/m³，exceeding the limit by a factor of 2.9. Analysis of raw materials showed that the percentage of n-hexane peak area in the cleaning agents used by the involved enterprises ranged from 10.88% to 12.42%. Clinical diagnosis included 6 cases of severe occupational chronic n-hexane poisoning and 1 case of moderate poisoning. All patients presented with typical peripheral neuropathy，and electromyography showed peripheral nerve damage in all four limbs. The investigation identified common problems across all three enterprises，including improper workshop layout，poor ventilation，unsystematic use of chemical solvents，and a failure to fulfill their primary responsibilities for occupational health. Conclusion Occupational chronic n-hexane poisoning is an occupational disease characterized by its insidious onset and tendency for cluster outbreaks，and the risk is particularly high in small and micro-sized enterprises. The main responsibility of enterprises should be strengthened to prevent the occurrence of n-hexane poisoning incidents.

Key words: n-hexane, Occupational chronic poisoning, Peripheral neuropathy, Workplace ventilation, Occupational health management, Small and micro enterprises