Development a technique for semi-quantitative risk assessment of exposure to chemicals

Employee exposure assessment through long-term monitoring is not feasible due to the complexity of sampling and analysis methods in all operating conditions. The use of chemical exposure risk assessment methods is an appropriate way to evaluate the exposure status of chemical workers in some situations. Of course, there is a need for special considerations to provide a comprehensive technique and to address the shortcomings of current methods such as disregard for existing control measures.

In this study, three factors influencing the risk of exposure to chemicals were considered based on the Control Banding (CB) approach, including the Health Hazard Index (HHI) indicating the inherent toxic properties of chemicals, Chemical Occupational Exposure Index (OEI) aims to show the characteristics associated with process conditions and material properties and exposure modes, as well as the Control of Effectiveness Index (CEI), taking into account the engineering and management measures that affect chemical exposure. Then, according to the above method, the risk of exposure to chemicals was investigated in Marun petrochemical Complex. 

Chemical exposure risk index (CRI) was calculated from the factors affecting exposure.Based on the findings of the study, exposure to benzene and 1,3 butadiene with a risk score of 20/01 and 14/35, respectively, obtained highest risk score in the HD unit and in the whole complex Due to the inherent hazards associated with these substances and other factors including exposure duration and poor effectiveness. Also, in all units, due to the low exposure time to chemicals, the lowest risk numbers were reported for similar exposure groups as the Boardman and the head of the unit. 

The present method can be used as a non-sophisticated and valid tool for risk assessment of occupational exposure to chemicals. Also, considering the role of control measures and their impact on risk score, this method will be able to provide a more accurate calculation of the working conditions of the personnel when exposed to chemicals.