Occupational chemical hazard risk assessment of benzene and its analogies in storage tank areas of petrochemical enterprises based on risk matrix method

Background The occupational hazards of benzene, toluene, ethylbenzenem, and xylene (BTEX) in storage tank areas of petrochemical enterprises seriously threaten the lives and health of workers.

Objective This study evaluates the occupational risk levels of BTEX in storage tank areas of three petrochemical production and storage enterprises by the reality-hazard-management (RHM) based comprehensive evaluation model for occupational chemical hazards.

Methods Three petrochemical enterprises in Hubei Province were selected to detect the BTEX concentrations in the storage tank areas according to relevant standards and codes. An optimized risk assessment index system for occupational chemical hazards was used to assess occupational health risk of the enterprises. The analytic hierarchy process (AHP) and the fuzzy comprehensive evaluation method were used to evaluate the quality of occupational health management of the enterprises. An RHM based comprehensive evaluation model was constructed with the above results based on the risk matrix method to comprehensively evaluate the level of BTEX in the storage tank areas.

Results The concentration of benzene in enterprise 2 was the highest, with a short-time exposure mass concentrations of 7.88-18.53 mg·m^-3 and a time-weighted average concentration of 1.26-2.30 mg·m^-3. The other enterprises did not show unqualified substances in storage tank areas. The occupational chemical hazard risk levels for benzene, toluene, and xylene were gradedⅠ, 0, and 0, respectively. The quality assessment results of occupational health management for the three selected enterprises were excellent, good, and good, respectively. The results of the RHM based comprehensive evaluation model showed that there was one A-level hazard (red), one C-level hazard (yellow), and seven D-level hazards (blue) in the storage tank areas of the three petrochemical production and storage enterprises.

Conclusion The RHM based comprehensive evaluation model can evaluate the hazard level of hazardous substances objectively and effectively. The occupational risks of BTEX in selected petrochemical tank farms are mostly at a low level, but there are still cases of high risks.