Causes of Countermeasures Against Serious Accidents Caused by Health Hazards of Chemical Substances, Based on Cases of Occupational Accidents in Japan

Abstract

The purpose of this study was to summarize the typical and specific causes and risk reduction measures of serious accidents in Japan caused by chemical substances in terms of the 10 types of human health hazards in the UN GHS (Globally Harmonized System of Classification and Labelling of Chemicals) classification. The list of "Cases of Major Accidents Caused by Chemical Substances" published on the "Safety in the Workplace Website" of the Ministry of Health, Labor and Welfare (MHLW) was linked to the "Results of GHS Classification by the Government" of the National Institute of Technology and Evaluation (NITE). Analysis was conducted by health hazards in order to obtain reference examples of measures taken against health hazards in response to the revision of the law on autonomous chemical substance management in 2022. Using the text mining tool KH Coder ver. Three using cluster analysis, we grouped causes and measures among serious disasters by health hazard, illustrated co-occurrence networks, and extracted typical examples of each in a co-occurrence network. Representative causes of and measures against occupational accidents caused by health hazardous properties were summarized from the extracted typical cases. Although few occupational accidents were caused by the health hazards of chemicals, when all health hazards were classified into acute toxicity, acute health hazard, and chronic health hazard, contact was a clear cause for many of the acute toxicity and acute health hazards, such as corrosiveness and sensitization. However, many occupational accidents were caused by the physical hazardous aspects of the chemical substances or by the safety aspects of the workplace. Causes of occupational accidents due to health hazards included unsafe behavior and unsafe conditions, or lack of understanding of the physicochemical properties of a substance and specific reactions such as mixing or hydrolysis of the substance. Typical risk reduction measures for health hazards included equipment to prevent human contact with health hazardous substances, systems to control unsafe behavior, promoting understanding of chemical reactions, and providing information about chemicals to all persons involved in testing, research, and subcontract work. The data of occupational accident cases of "death or more than 4 days lost from work" were used. Most of the cases were related to acute health hazards, but relatively few to chronic health hazards, and few occupational accidents were caused by health hazards. Most of the occupational accidents were caused by health hazards due to the physical hazards of chemical substances and inadequate workplace safety. In light of the above, it is necessary in autonomous chemical substance management to first take risk reduction measures for workplace safety and chemical physical hazards, then to prevent contact with acute toxicity and acute health hazards such as corrosiveness and sensitization, and, lastly, to take risk reduction measures for chronic health hazards, using allowable concentrations and controlled concentrations as indices.