Over 1,100 sprinkler heads were corroded by the time of the blaze
The U.S. Chemical Safety and Hazard Investigation Board (CSB) released its final report Tuesday on a chemical fire at the BioLab facility in Conyers, Georgia, concluding that the plant was storing more than twice the amount of swimming pool chemicals it was designed to hold and that a corroded sprinkler system allowed water to contact those chemicals, triggering the blaze.
The fire on Sept. 29, 2024, sent a huge plume of orange and black smoke into the sky and forced residents to shelter in place.
The CSB found that components of the sprinkler system inside the BioLab plant “had been experiencing significant corrosion and leaking” since 2019, according to the report. That was shortly after the company began storing the chemicals at the plant.
The report said that the large sacks of pool-treatment chemicals “would naturally off-gas chlorine fumes that combined with ambient humidity in the warehouse and condensed as hydrochloric acid droplets” on the metal sprinkler heads.
During a sprinkler inspection in December 2023 at the plant in Conyers, about 25 miles southeast of downtown Atlanta, over 1,100 sprinkler heads were found to be corroded, the CSB said.
On the day of the fire, a corroded sprinkler system component failed. Water came into contact with the chemicals and set off a decomposition reaction that generated heat, causing the release of smoke, toxic vapors and fire, the report said.