CSB Renews Calls to Expand EPA RMP and OSHA PSM Coverage of Reactive Hazards
In July 2026, the U.S. Chemical Safety and Hazard Investigation Board (CSB) published its investigation report concerning chemical decomposition, fires, and a toxic gas release at the Bio-Lab Conyers facility in Conyers, Georgia. The report calls for revisions to OSHA’s Process Safety Management (PSM) standard and EPA’s Risk Management Program (RMP) rule to cover reactive hazards and prevent similar incidents.
The Incident
On the morning of September 29, 2024, the Bio-Lab Conyers facility experienced a chemical reaction involving hazardous chemicals that caused extensive off-gassing, excessive heat generation, multiple fires, and a large plume of toxic smoke containing chlorine, hydrogen chloride, bromine, and other substances. These conditions prompted shelter-in-place orders, evacuations, and road closures by local authorities. Roughly 17,000 people in the surrounding community were evacuated, and local media reported that 90,000 people in the Atlanta metropolitan area were advised to shelter in place due to toxic smoke from the fires.
The CSB determined that the incident began when water from a failed sprinkler-system component contacted chlorinated isocyanurates stored in the warehouse, initiating a decomposition reaction. The reaction generated heat that activated additional sprinkler heads, causing water to contact additional chlorinated isocyanurates and other chemicals. The resulting reactions generated additional heat, contributing to further decomposition, toxic vapors, smoke, and fires.
CSB-Identified Safety Issues and Regulatory Gaps
The CSB identified several safety issues contributing to the incident, including Bio-Lab’s approach to maintaining its corroding sprinkler system and its failure to adequately identify hazards associated with storing chlorinated isocyanurates.
The CSB also found gaps in PSM and RMP coverage of reactive hazards. The reactive chemicals stored at the facility fell outside PSM and RMP. Had the company’s storage of these materials been covered, Bio-Lab would have been required to implement hazard-assessment, prevention, and mitigation measures to reduce the likelihood or severity of an incident. Although other safety requirements and standards applied to aspects of Bio-Lab’s operations, the CSB concluded that the incident illustrates a broader gap in how PSM and RMP address reactive hazards.
The fact that Bio-Lab was not covered by PSM did not mean it was entirely unregulated by OSHA, however. The CSB explains that the storage and handling of chlorinated isocyanurates and bromochloro-5,5-dimethylimidazolidine-2,4-dione (BCDMH) remained subject to OSHA’s General Duty Clause.
OSHA also issued citations involving HAZWOPER, 29 C.F.R. § 1910.120, and the Respiratory Protection standard, 29 C.F.R. § 1910.134. According to the CSB report, OSHA issued six citations totaling $61,473, which had been paid by the time the report was published.
CSB Recommendations
The CSB recommended that OSHA amend the PSM standard to more comprehensively address reactive chemical hazards capable of causing catastrophic incidents. The CSB identified a similar regulatory gap under EPA’s RMP rule. Specifically, it advised that EPA revise the RMP regulations to explicitly cover catastrophic reactive hazards capable of seriously affecting the public, including hazards arising from:
- self-reactive chemicals;
- combinations of chemicals; and
- process-specific conditions.
What This Means for Chemical Manufacturers and Facilities that Use Chemicals in Manufacturing
CSB notes that facilities storing, using, and manufacturing hazardous chemicals have an obligation not only to understand the full hazards and risks associated with the chemicals, but to effectively assess and manage the risks inherent in the storage and handling of these materials to avoid the occurrence of an incident. A key lesson highlighted in the report states, “Even in the absence of regulatory requirements for risk assessments, organizations should ensure that all hazards of using and storing hazardous chemicals be assessed and properly mitigated.”
