When Georgia environmental officials analyzed the first ash samples collected after the September 2024 BioLab chemical fire in Conyers, Ga., one element immediately stood out: chromium.
The element chromium occurs naturally in some soils and is generally non-toxic. But when it burns, such as during a chemical fire, it can change into a cancer-causing compound.
The fire at the BioLab chemical facility sent a toxic plume over Rockdale County. More than 17,000 residents evacuated. Another 90,000 sheltered in place. A report by the U.S. Chemical Safety Board found BioLab was storing nearly 14 million pounds of reactive chemicals when the storage warehouse caught fire — more than twice the amount the company initially intended to store.
In an email obtained by GPB in November 2025, a Georgia Environmental Protection Division risk assessor warned that the fire’s extreme heat could have transformed relatively harmless chromium into hexavalent chromium — the carcinogenic compound made infamous by the 2000 film Erin Brockovich, which won Georgia-born actress Julia Roberts an Oscar for her portrayal of the California environmental activist who exposed the cancer-causing agent.
It’s also the same chemical by-product of burning coal that residents of the Middle Georgia town of Juliette have alleged for years has made them sick as it has flowed from Georgia Power’s coal ash pond at its Plant Scherer and into their drinking water.
Georgia EPD’s risk assessment manager’s October 2024 email to colleagues within the organization recommended “that hexavalent chromium be analyzed for if the ash is sampled again.”
RELATED: BioLab closing Conyers plant
But by August 2025, when GHD USA, an environmental contractor hired by BioLab, submitted a cleanup plan, hexavalent chromium was explicitly excluded from testing.
The GHD contractor stated in its plan that the carcinogenic form of chromium was “highly unlikely to be found” and “Cr6+ will not be sampled.”
Georgia EPD approved the plan in October 2025.
Independent scientists who reviewed the documents for GPB said GHD’s decision to not test for the chemical is difficult to defend.
Dr. Ted Schettler, science director of the national nonprofit advocacy group Science and Environmental Health Network and a former EPA advisory committee member, reviewed the testing documents at GPB’s request.
He said the BioLab fire created textbook conditions for hexavalent chromium formation.
“The heat from the fire, because the fire was burning in oxygen — it’s an oxidizing reaction — that, in itself, would contribute to chromium-3 being converted to chromium-6,” Schettler said. “And then the chemicals in that fire in Conyers were oxidizing chemicals. So it was a highly oxidizing environment.”
Given that BioLab’s sampling found elevated total chromium and the fire involved chlorine-based chemicals, including trichloroisocyanuric acid (TCCA), burning at high heat, Schettler said hexavalent chromium should have been the default assumption.
“The [GHD and EPD] sampling that was done in the soil showed elevated levels of chromium. They were substantially elevated in several samples,” he said. “So, you almost should be assuming that a lot of that would be chromium-6, because there was a fire there, and because it was that kind of fire with all these oxidizing chemicals.”
More chromium was found in later sampling
That initial October 2024 ash sample that prompted EPD’s warning contained 2.6 mg/kg of total chromium. According to the email, it was enough to put cancer risk just below the state’s threshold for “unacceptable risk.” But additional samples collected by GHD months later from waste materials and pond sediment at the BioLab site showed concentrations as high as 35.4 mg/kg — more than 13 times the initial level.
All were tested only for total chromium. None were speciated to determine if the carcinogenic hexavalent form was present.
Schettler noted that the EPA’s regional screening level — that is, the concentration that triggers concern — “begins at slightly less than 1 milligram per kilogram” for chromium, with the threshold for hexavalent chromium much less than one milligram per kilogram in various states.
“When you’re talking about 26 milligrams per kilogram, you’re more than 25 times higher than what’s considered an acceptable soil level,” Schettler said. “Now, if it’s all chromium-3, you have less of a problem, but until you speciate, you simply don’t know.”
Speciation testing can distinguish the toxic form of chromium (Cr6+) from benign chromium (Cr3+).
The contractor’s justification for excluding hexavalent chromium testing was that it would “quickly reduce” to the less toxic form.
Schettler said that doesn’t match the science.
“I can say that Cr6+ does slowly revert to Cr3+ over time, and the timing will vary from weeks to months to years,” he said. “It is not rapid.”
The conversion speed depends on local soil composition. The fact that elevated chromium was found in samples collected two to four months after the fire raises questions about whether quick reduction occurred. But again, without speciation testing, there’s no way to know.
“Over that period of time, if there is a significant amount of Cr6+ in the soil while it’s slowly reverting to Cr3+, people are potentially exposed,” Schettler said.
California wildfire studies echo Georgia EPD concerns
Erin Brokovich’s work for states to acknowledge cancer risk from hexavalent chromium most recently involved the California State Water Board adopting a Hexavalent Chromium MCL Regulation in October 2024.
The Georgia EPD risk assessor’s October 2024 email also cited California’s emerging wildfire studies when warning about hexavalent chromium formation.
Dr. Michael Kleeman, an environmental engineer at the University of California (UC), Davis led recent wildfire research that confirmed fires routinely convert benign chromium (Cr3+) into the carcinogenic form after the 2025 Los Angeles wildfires, and found that combustion of building materials and infrastructure creates conditions for chromium oxidation.
“The chemical fire at the BioLab facility in Conyers, Ga., seems very unique given the direct involvement of chlorine-based pool chemicals,” Kleeman said in an email to GPB in December 2025. “So it seems possible that some amount of Cr6+ formed in this fire, even if the temperatures were only modest compared to much larger urban wildfires.”
The wildfire research was released in August 2025 as a preprint so residents near cleanup zones could take immediate steps to reduce exposure.
“The best outcome for the public occurs when the regulatory agencies and the research community works together to cover the full suite of pollutants of concern,” Kleeman said.
Georgia residents were never told
Ashley Clotfelter, who lives in a neighborhood east of the BioLab facility in Conyers, Ga., was ordered to evacuate the day of the fire by a police officer wearing a gas mask. She spent that night at a friend’s house a few miles away. By the next morning, when she briefly returned home to walk her dogs, she had developed a low-grade fever and a persistent headache.
“I don’t get headaches,” she said. “And this one didn’t go away.”
That same week, she noticed debris, what looked like roofing shingles, scattered across her lawn. Other neighbors reported ash-like material, pieces resembling black styrofoam, coating their cars and properties.
Clotfelter suspected official testing would be incomplete, but she didn’t know about the chromium warning until GPB shared the documents in December 2025.
“I knew it was coming,” she said. “I think it’s just typical government and big business corruption and protecting rich businesses.”
The emails and documents obtained by GPB in November 2025, which span communications between September 2024 and October 2025, contain the first mentions of chromium in any post-fire monitoring records reviewed by GPB News since September 2024. Chromium was not listed in public-facing air quality updates or early response summaries released during the emergency phase.
EPD did not respond to GPB’s request for comment. BioLab and GHD also did not provide comment on this story.
“I’m just hoping to never notice something bad happen,” Clotfelter said. “But that’s how people get cancer all the time. It’s just everywhere.”
Schettler said residents deserve answers.
“People living there should really have a strong sense of what they’re facing. Or what they’re not facing.”