New CSB Report Highlights Reactive Hazards of Pool-Treatment Chemicals
The Sept. 29, 2024, chemical fire and toxic gas release at a Bio-Lab Inc. warehouse in Conyers, Georgia, occurred after chlorinated isocyanurates, or pool-treatment chemicals, stored in the warehouse came into contact with water, explains the final investigation report by the U.S. Chemical Safety and Hazard Investigation Board. CSB’s investigation of the incident found that the facility continued using its corroding sprinkler system rather than proactively maintaining it to prevent leaks. When a component of the sprinkler system failed, allowing water to contact the chlorine-based chemicals stored in the building, the resulting chemical reaction generated “significant heat, fires, and a massive plume of toxic smoke that contained chlorine, hydrogen chloride, bromine, and other substances,” the agency’s news release states. The toxic smoke from the fires prompted the evacuation of 17,000 people from the surrounding community and shelter-in-place orders affecting 90,000 people in the Atlanta metropolitan area.
Factors that CSB says increased the severity of this incident include the failure of the Bio-Lab Conyers facility to identify the hazards of storing large quantities of oxidizer chemicals, including chlorinated isocyanurates, and to manage environmental conditions, such as humidity levels, inside the warehouse. The large quantities of chemicals stored—around 14 million pounds, or more than double the amount of the “average inventory” anticipated to be stored in the warehouse according to documentation submitted to local authorities in 2019—and poor storage configurations “hindered emergency response access to the initial reacting material” on the morning of the incident, CSB’s report states. The agency explains that the approximately 14 million pounds of chemicals were stored in “super sacks,” each of which held around 2,200 to 2,800 pounds of material. Many of these super sacks were double-stacked in multiple rows, which prevented employees and emergency responders from accessing the area where the first off-gassing occurred. CSB also cites the organization’s failure to address the risks of storing large quantities of chlorinated isocyanurates and the lack of regulatory coverage for these and other reactive chemicals as additional contributors to the incident’s severity.
Earlier incidents at Bio-Lab facilities offered opportunities for the organization to incorporate lessons learned from similar chemical releases. CSB previously investigated the Georgia Bio-Lab facility in September 2020 after a release of hazardous chemicals caused by a chemical reaction and decomposition following a water line leak that led to flooding in the building. The agency says the incident exposed Bio-Lab workers and firefighters to “dangerous fumes” and led to a six-hour closure of a nearby interstate. The September 2020 investigation in Conyers, Georgia, was in conjunction with CSB’s investigation of the chemical fire and toxic gas release that occurred a month earlier at Bio-Lab’s Lake Charles facility in Westlake, Louisiana, following Hurricane Laura.
CSB’s final investigation report reiterates its longtime recommendations that OSHA and EPA amend regulations “to achieve more comprehensive control of reactive hazards that could have catastrophic consequences.”
“Although the chlorinated isocyanurates and other substances involved in this incident have reactive characteristics and the inherent ability to produce toxic gas, they are not covered by the U.S. Occupational Safety and Health Administration’s Process Safety Management standard or the U.S. Environmental Protection Agency’s Risk Management Plan rule,” notes CSB Lead Investigator Vonzella Vincent.
According to Sylvia Johnson, a CSB board member, the agency has urged OSHA and EPA to address regulatory coverage for reactive chemicals since 2002. CSB’s report recommends that OSHA amend its PSM standard to “cover reactive hazards resulting from process-specific conditions and combinations of chemicals” and that EPA revise its accidental release prevention requirements “to explicitly cover catastrophic reactive hazards … including those resulting from self-reactive chemicals and combinations of chemicals and process-specific conditions.”
Further details about this investigation can be found in CSB’s news release and its final report (PDF).