A chemical reaction sparked a massive fire and plume of toxic smoke at a Georgia laboratory in September, endangering nearby communities and metro Atlanta, according to findings released by the U.S. Office of Chemical Safety ( CSB).
Photo from the US Office of Chemical Safety
The CSB released its report Friday, detailing the events surrounding the September 29 chemical fire at the BioLab facility in Conyers, and Georgia.
According to the CSB, the main substances involved in the incident are chemicals commonly used for cleaning and disinfection:
bromochloro-5,5-dimethylimidazolidine-2,4-dione (BCDMH), trichloroisocyanuric acid (TCCA) and dichloroisocyanurate de sodium (DCCA). These chemicals, stored in the factory warehouse, generated heat as they degraded, eventually breaking down and releasing vapors toxic substances which started the fires, indicates the CSB in its report.
US federal authorities have provided an update on their investigation into the fires at the BioLab chemical plant near Atlanta, whichcreated a cloud of toxic chemicals and forced the surrounding inhabitants to take shelter.
The fires, which broke out on September 29 in the factory BioLab of Conyersproduced a huge plume of orange and black smoke visible throughout the region. Friday, the US Office of Chemical Safety and Hazard Investigation released details of the incident.
BioLaba subsidiary of KIK Consumer Products, based in Lawrenceville(Georgia), manufactures chemicals used for kill algae and bacteria in swimming pools and hot tubs.
In a statement, the company noted its “strong track record of constructively engaging” with regulators and pledged to fully cooperate with the federal investigation. “We remain firmly committed to understanding the causes of the incident and repairing the damage caused to residents and business owners in the affected region,” the statement read.
According to the report, a BioLab employee assigned to monitor fires in the Plant 12 storage warehouse heard a “pop” around 5 a.m. as he left a break room for a fire check. routine. The employee immediately noticed that a water-reactive product had become wet and contacted the only other staff member on site. Despite there being no initial flames, the employee's attempts to isolate the chemical were unsuccessful. At 5:10 a.m., they called 911 after noticing “large plumes of toxic vapor” forming inside the building.
By 6:30 a.m., flames were visible through the roof where the reaction had occurred, prompting an initial shelter-in-place order at 7:40 a.m. Rockdale County firefighters extinguished the fire approximately 30 minutes later. However, a second fire broke out around noon, producing “thick black smoke, followed by multi-colored plumes,” according to the report. Evacuations began at 12:30 p.m. and the fire chief confirmed the fire was out by 4 p.m.
The fire caused significant structural damageparts of the building having collapsed. The Factory 12 warehouse, a bulk storage facility spanning an area larger than five football fields, was completely destroyed. According to investigators, the site remained an “active emergency response scene” for nearly four weeks.
The Plant 12 warehouse was separated from the main warehouse by a fire wall and fire shutters. BioLab informed investigators that a permanent fire watch had been put in place two or three months earlier due to “strong odors of oxidants” in Plant 12 and another storage building.
The incident also disrupted transportation, as Interstate 20, which runs parallel to the facility, was closed shortly after the building collapsed, around 1 p.m. The highway reopened the next morning at 7 a.m., but surrounding roads and a two-mile shelter-in-place zone imposed by the Rockdale County Emergency Management Agency remained in effect for weeks, and were not lifted until October 17.
Smoke from the fire drifted toward Atlanta, creating a haze and smell of chlorine in parts of the city and surrounding areas.
The disaster gave rise to more thana dozen legal proceedings against the company.
Learn more:
Coverage for September 30:
CNN :
https://www.cnn.com/2024/09/29/us/rockdale-county-biolab-fire-georgia/index.html
The Guardian: Georgia chemical plant fire forces tens of thousands to seek shelter.
https://www.theguardian.com/us-news/2024/oct/01/georgia-biolab-chemicals-smoke-evacuation
More information on the CSB report:
https://www.csb.gov/us-chemical-safety-board-releases-investigation-update-into-september-2024-massive-fire-and-toxic-plume-at-bio-lab-facility-in-georgia/
https://roughdraftatlanta.com/2024/11/25/biolab-chemical-fire-investigation/
https://www.nbcnews.com/news/georgia-chemical-fire-investigation-rcna181541
What is thermal decomposition?
When common cleaning agents containing reactive chemicals, such as oxidizing agents, undergo decomposition thermaltheir molecules decompose into simpler compounds under the effect of high temperatures. This process is often exothermic, meaning it releases heat, which can accelerate decomposition and potentially lead to an explosion.
Here is a breakdown of the chemical events:
-
Oxidizing agents are key components:
Many cleaning agents contain chemicals such as
-
Thermal breakage of liaisons :
Under the effect of heat, the chemical bonds of these compounds weaken and break, producing:- reactive gases (for example, oxygen, chlorine or nitrogen oxides)
- thermal energy which can accelerate the reaction
- Increased gas pressure:
As the gases are released quickly, the pressure increases in a confined space, such as a storage container or warehouse.
4. Combustion or explosion:
If the gases are flammable or reactive (for example, chlorine or oxygen), they can ignite in the presence of a spark or heat source:
- and firefueled by the oxidizing properties of chemicals
- A thermal explosioncaused by rapid gas expansion and inflammation.
5. Chain reactions:
The heat and reactive gases produced can cause surrounding materials to decompose, increasing the intensity of the fire or explosion.
Example: Thermal decomposition of TCCA
TCCA decomposes under heat releasing chlorine gas (Cl₂) and oxygen (O₂), both of which are very reactive. These gases can cause:
- combustion when combined with flammable materials
- toxic fumes, adding a secondary risk to the explosion.
Main security concerns
The risk of thermal decomposition and explosion increases when these chemicals are:
- stored inappropriately
- Exposed to high temperatures
- contaminated by moisture, which can accelerate decomposition reactions.
Sources on thermal decomposition:
Chemical & Engineering News
DMSO poses a decomposition hazard – Chemical & Engineering News
September 15, 2020 – In 1985, for example, an explosion at a waste treatment plant that distilled DMSO and 1-chloro-2,3-epoxypropane left one person injured and one dead – one of many accidents of this type listed in…
Inspectioneering
Thermal decomposition for cleaning heat exchangers – Inspectioneering
February 27, 2018 – Thermal decomposition: A technique for cleaning process equipment … thermal decomposition in an oxygenated environment and; thermal soaking in the absence of oxygen. This content is available for…
Fire Science Review
Fire toxicity of polyurethane foams – Fire Science Reviews
April 20, 2016 – Polyurethane is widely used, its two main applications, furnishing and insulation, having low thermal inertia and therefore high flammability. In addition to their flammability, polyurethane foams…
Purdue Engineering
Potential explosion hazards associated with the use of DMSO and DMF in chemical reactions
Potential Explosion Hazards of DMSO with Oxidizers – An explosion involving the thermal decomposition of DMSO in the presence of HClO 4 was published in 1971. – One death caused by an explosion involving DMS…
SpringerLink
Fire extinguishing systems by total flooding of clean agents
Explosion suppression systems use rapid distribution of agent following very early detection of inflammation. These systems use much larger quantities of agents (than flame extinguishing or inertion systems)…
NIST
RESULTS OF THERMAL DECOMPOSITION PRODUCTS USING PFC-410 (3M BRAND PFC…
PFC-410 is a clean extinguishing agent, it vaporizes completely and requires no cleanup after a system discharge. It is a very stable, inert and electrically non-conductive gas. It is a very stable, inert and electrically non-conductive gas.
NIST
A REVIEW OF TESTING OF HALOCARBON THERMAL DECOMPOSITION PRODUCTS…
The objective of these tests was to study the effect of agent concentration on extinguishing times and thermal decomposition products. The results of these tests were used as a basis for the design…
Wikipedia
Thermal decomposition – Wikipedia
Thermal degradation processes of organic matter at atmospheric pressure… Thermal
