Tehran University of Medical Sciences International Journal of Occupational Hygiene 2008-5109 12 2 2020 07 30 140 153 Fatemeh Sadeghi Gelvardi Department of Environmental EDepartment of Environmental Engineering, West Tehran Branch, Islamic Azad University, Tehran, Iranngineering, West Tehran Branch, Islamic Azad University, Tehran, Iran Behnoush Khoshmanesh Department of Environmental Engineering, Parand Branch, Islamic Azad University, Parand, Iran Farin Fatemi Research Center for Health Sciences and Technologies, Semnan University of Medical Sciences, Semnan, Iran Seyed Shamseddin Alizadeh Department of Occupational Health Engineering, Health Faculty, Tabriz University of Medical Sciences, Tabriz, Iran Neda Gilani Department of Statistics and Epidemiology, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran; Emergency Medicine Research Team, Tabriz University of Medical Sciences, Tabriz, Iran 2020 11 16 2020 12 01 Hazardous chemical accidents have increased in the previous decade in Iran. The analyses of these accidents helps inform accident prevention in the future. This study was aimed to characterize and analyze the chemical accidents occurring in Iran during the period of 2018-2020. This cross-sectional study was conducted in 2020. Data were obtained from the registered chemical accidents checklists in the inspection database at Ministry of Health. Descriptive analyses were applied to characterize the hazardous chemical accidents based on time, place, death, injuries, type, and cause of injury. Odds ratio and Chi de test assessed how the main variables under study were associated with the occurrence of hazardous chemical accidents. Analytical tests of Chi-square test and Chi-square test by means of Monte Carlo simulations were used to investigate the relationship between the main variables studied and the occurrence of chemical accidents. The results showed that more than half of these chemical accidents occurred in basic chemical installations and manufacturers. Among the direct causes of assessed chemical accidents, 45% of them were related to equipment/utilities failure. Providing safety data sheet for chemicals, chemical labeling, and emergency response plan as the main components of chemical safety management program were significantly related to occurrence of chemical accidents  in the chemical enterprises (P-value=0.01). In spite of the implementation of chemical safety management program since 2015 in Iran and routine inspection by chemical enterprises, the trend of hazardous chemical accidents is increasing. The economically developed provinces particularly, medium and small sized chemical enterprises, need more official rules and strict supervisions in order to prevent accidents and mitigate the harmful consequences. https://ijoh.tums.ac.ir/index.php/ijoh/article/view/476 https://ijoh.tums.ac.ir/index.php/ijoh/article/download/476/618