CSB update on the BioLab fire in Conyers, GA

Via NBC, I see that the CSB has released its preliminary update on the Conyers, GA fire: 

Washington D.C. November 22, 2024 – Today, the U.S. Chemical Safety and Hazard Investigation Board (CSB) released an investigation update into the chemical reaction and toxic gas release on September 29, 2024, at the Bio-Lab, Inc. facility in Conyers, Georgia, that resulted in a massive fire and plume of toxic smoke that threatened the surrounding community and the metropolitan Atlanta area.

The reaction involved materials stored in a warehouse that generated heat, which led to the  decomposition of the product, the release of toxic vapors, and fires.  The primary substances involved in the reaction were trichloroisocyanuric acid (TCCA) and sodium dichloroisocyanurate (DCCA), along with bromochloro-5,5-dimethylimidazolidine-2,4-dione (BCDMH).  The resulting massive plumes of toxic smoke contained chlorine and other hazardous substances and caused significant offsite impacts. 

No major root cause updates as of yet, but the brown/red smoke is most likely from the bromo compound. Full report here.