Given that employees in petrochemical industries are exposed to various pollutants and are exposed to serious risks, the need for a comprehensive risk assessment program to determine hazardous chemicals that affect the health of exposed individuals and also to determine hazardous processes and tasks seems essential. Study Method: This cross–sectional–case study was conducted in 3 stages. The first stage included identifying hazardous substances and determining the risk factor of chemicals, the second stage included assessing exposure to benzene, and the third stage included estimating the relative risk of COVID–19 due to exposure to benzene through epidemiological studies. Findings: According to the risk assessment method, 40 chemicals were identified in the entire petrochemical company studied. Benzene was introduced as the most hazardous chemical. The results of the second stage showed that people in the main site during the noon shift and in the aromatic site with an average exposure of 4.29 ppm had the highest exposure to benzene. According to the results of the estimation stage of relative risk of COVID–19 in exposure to benzene, the highest relative risk in workers at my site was found to be related to workers in the aromatic unit, who had a cumulative exposure of 149.4 ppm–years (ppm–years) and a relative risk of 3.2. The statistical test result also showed that there was a significant relationship between the level of exposure to benzene and different work groups (P<0.001). Discussion and Conclusion: This study showed that benzene achieved a risk level of 5 with a risk coefficient of 4.5–5, indicating that corrective measures for this highly hazardous and carcinogenic chemical should be initiated as soon as possible. Schematic of the mechanism analysis and impact of the COVID–19 pandemic and outbreak on petrochemistry and petroleum mechanics.