2024 Bio-Lab fire and chemical plume caused by improper chemical storage

aquatic environments leaking from the damaged sprinkler came in contact with chlorinated isocyanurates, initiating a decomposition interaction that led to fires and a substantial plume of toxic smoke and gases containing chlorine, hydrogen chloride, bromine, and other substances, the CSB confirmed. There were no injuries reported however approximately 17,000 residents were evacuated and the dangerous releases continued to several days.

In April 2025, the US federal Occupational security and Health Administration (Osha) fined Bio-Lab greater than $61,000 (£46,000) to security violations and concluded that the trigger was ‘improperly stored hazardous chemicals’.

The CSB’s final report finds that when the Bio-Lab warehouse was built in 2019 it was supposed to contain an ‘average inventory’ of about 2800 metric tonnes of raw materials, including oxidisers, however it was storing over 6000 tonnes of chlorinated isocyanurates and other reactive chemicals by the time of the September 2024 incident. That is greater than twice the amount that the company initially indicated to regional officials, according to the CSB.

In addition, the agency points to Bio-Lab’s inventory records indicating that there were approximately 5000 ‘super sacks’ inside its warehouse at the time of this catastrophic event, and each contained around a tonne of chlorinated isocyanurates. Unfortunately, the CSB found, these woven polypropylene bags were not waterproof and were stacked in ways that exacerbated the issue.

‘The conditions and circumstances at the Bio-Lab Conyers warehouse were completely unacceptable,’ stated CSB chair Steve Owens, noting that correct safeguards were not in place.

In recent years, there have been several other incidents in the US involving pool treatment chemicals that resulted in the emit of chlorine gaseous or other possibly toxic byproducts, noted Vonzella Vincent, the CSB lead investigator. That includes a September 2020 incident at Bio-Lab’s Lake Charles facility in Louisiana.

while the chlorinated isocyanurates and other substances involved in this incident have reactive characteristics and the inherent ability to create toxic gaseous, Vincent pointed out that they are not covered by Osha’s Process security regulation standard or the US ecological preservation Agency’s Risk regulation Plan rule, which is designed to prevent accidental releases of extremely hazardous substances and minimise their possible impact on regional communities or the ecological stability.

‘We urge OSHA and the EPA to act to expand coverage of these hazardous chemicals so that severe incidents, like the one at BioLab Conyers, do not keep happening,’ stated Sylvia Johnson, the CSB’s only current member besides Owens. ‘These incidents negatively impact workers and the adjacent communities,’ she said.

The CSB, which currently only has two members and is operating at 40% board capacity, has been calling to greater regulatory coverage of reactive chemicals to over two decades.

The Trump administration had proposed to shut down the agency, which is only independent US federal agency charged with investigating manufacturing chemical accidents and developing recommendations to prevent their recurrence, by October 2025. however earlier this year, the US Congress intervened and maintained the CSB’s funding at $14 million to the remainder of the financial year, until 1 October 2026.