CSB Publishes 2nd Update on BioLab Fire

Yesterday the Chemical Safety Board (CSB) announced the publication of their second update on their investigation of the chemical fire that consumed the Conyers, GA warehouse of the Bio-Lab company in September of 2024. Their first investigation update was published on November 22^nd, 2024. The Bio-Lab incident garnered national attention when 17,000 people were evacuated from the area around the facility during the height of the incident and nightly shelter-in-place warnings were issued for portions of Atlanta, GA due to the toxic cloud released during the multi-day incident. There were no reported injuries or deaths related to the fire.

While the CSB has not yet identified the source of the water that initiated the chemical reaction that caused the fire, this new update notes that (pg 14):

“Due to the storage of TCCA and DCCA outside the bunker, near the firewall, Bio-Lab personnel also reported observing corrosion on the sprinkler heads outside the bunker, which led to multiple sprinkler head failures and leaks where fire protection piping and pipe couplings were corroded. At the time of the incident, most of the sprinkler heads outside the bunker were still brass-finish heads, as specified and installed during the construction of the storage warehouse in 2019. According to Bio-Lab, the corrosion-resistant sprinkler heads would not provide adequate fire protection for the warehouse rack storage. Therefore, the corroded sprinkler heads outside the bunker were replaced in kind.”

CSB also notes that: “Similarly, corrosion on the fire protection system piping was observed by CSB personnel in February 2025 at the third-party warehouse in Texas, where Bio-Lab began storing TCCA and DCCA in November 2024 after the Bio-Lab Conyers incident.”

The report also notes that first responders reported water in the storage area (pgs 7-8):

“When two responders entered the building for reconnaissance, both described hearing water falling throughout the building and noted that a large volume of water was flowing out of the building through the dock doors. Both Bio-Lab and RCFR personnel also had observed large volumes of water running out of the dock doors even before the RCFR respondents flowed any water, suggesting the sprinkler system was activated.”

Another new bit of information that was not included in earlier discussions is the fact that TCCA produces Nitrogen Trichloride (NCl3), an explosive liquid. The report notes (pgs 9-10):

“Because TCCA and DCCA produce nitrogen trichloride when wet, which is an explosive material that is unstable when exposed to air, RCFR responders reported observing chemical reactions in the form of “small explosions” with product physically shooting out from the building, as well as hearing “popping” sounds. RCFR personnel explained that they had to relocate one of their engines because it was “getting pummeled” by the reacting product and that “it sounded like you were at the gun range with pow, pow, pow, pow, pow.””

The most concerning information, though, to come out of this report is the fact that the water reactive nature of TCCA is not mentioned in the Safety Data Sheet from manufacturers of the material. The report notes that (pg 4):

“Although TCCA and DCCA are known to have water-reactive properties, according to the NFPA and the International Fire Code definitions of water-reactive materials, the predominant manufacturers of the material do not list their reaction with water in the storage, hazard statements, or precautionary statement sections of the SDS.”

This new report concludes by outlining the remaining investigative areas that the CSB is pursuing:

• Testing the solid oxidizer(s) to quantify their water reactivity characteristics, including the heat of mixing, thermal stability, and fully define the conditions where the material behaves hazardously upon contact with water,

• Information and evidence to help determine the most likely water source that initiated the chemical reaction,

• Storage and handling of oxidizers that also have water-reactive characteristics,

• Regulatory and Industry guidance on storage and handling of reactive materials, and

• Regulatory and Industry guidance on design, maintenance, and inspection of fire protection systems.