Abstract: In order to reveal the vulnerability of safety management systems in Chinese chemical industry, firstly,based on the characteristics of chemical accidents,the specific manifestations of each cause category in HFACS were identified. Then ,HFACS model was supplemented,and an analysis of causes of accidents was made using the supplemented HFACS model on the basis of data on a certain chemical enterprise's 102 accidents occurred in 2012-2016. Finally, corresponding improvement and control measures were proposed to prevent chemical accidents in the future.The results show that the unsafe behavior of employees is mainly manifested in the routine violations and skill-based errors, and its main cause is lack of risk assessment for equipment or process, that the root causes of the operator's unsafe behavior are the poor concentration and vigilance of operator in adverse mental state factors, and without wearing PPE, that main forms of unsafe supervision are lack of providing both safety supervision and risk assessment,and that organizational influence factors are mainly manifested in lack of a safety climate.

Key words: chemical accidents, human factors analysis and classification system (HFACS), accident-cause, personal protective equipment(PPE), unsafe acts