Abstract: In order to effectively reduce unsafe behavior in university laboratory. Firstly, FBN model of unsafe behaviors in university laboratories was constructed by using HFACS model, Bayesian network method, expert assessment and triangular fuzzy number probability estimation methods. Then, main influencing factors of unsafe behavior in university laboratory were determined by model reasoning analysis. The results show that there are many risk factors for unsafe behaviors in university laboratories, including 24 risk factors at five levels: external influence, organizational influence, unsafe supervision, preconditions for unsafe behaviors and unsafe behaviors. As a result, unacceptable probability of unsafe behavior is as high as 86 percent. Among 24 risk factors, sensitivity value of poor organizational climate is 24.1%, which has the greatest impact on unsafe behavior. The most fundamental factor leading to unsafe behavior is inadequate legislation, which in turn passes to unacceptable external factors and unsafe supervision, forming the most likely causal chain.

Key words: fuzzy Bayesian network (FBN), university laboratory, unsafe behavior, risk assessment, human factors analysis and classification system (HFACS) model