Chlorine gas poisoning at drinking water facilities

The victim of this accident suffered from acute pneumonia when he was engaged in work to add hypochlorous acid soda, etc., to a tank for the drinking water facilities at a hot springs site.

The victim who was on the day shift continued working as he was also taking a night shift in place of his colleague.

During a routine patrol of drinking water facilities around 8:45 p.m., the victim found that only about 10 percent of the volume of polychlorinated aluminum and hypochlorous acid soda remained in the stirring tanks. Accordingly, the victim first replenished the hypochlorous acid soda. When the victim opened the tank cover to replenish polychlorinated aluminum, a strong chlorine-smelling vapor was emitted and the victim inhaled the gas.

Because of inhaling, the victim started coughing violently, with the severely irritating odor of the gas infusing his nasal passages and lungs. As the victim continued to have symptoms that included burning in his throat and chest, he underwent an examination at a hospital where he was diagnosed with acute pneumonia and liver function impairment due to chemical damage.

1.       As hypochlorous acid soda was mistakenly put in the tank for polychlorinated aluminum, chlorine was generated due to a chemical reaction within the tank.

2.       Hypochlorous acid soda and polychlorinated aluminum were contained in similar-appearing bags that made it difficult to distinguish between the two, and no clear distinction was made in the storage warehouse either.

3.       Safety and health education was not provided with respect to the characteristics of the substances handled and the dangers, etc., when they are mixed.