Study documents potentially hazardous flame retardants in firefighter gear

(Press-News.org) Some firefighter gear is manufactured with chemicals called brominated flame retardants that could pose a risk to firefighter health, according to a new study published in Environmental Science & Technology Letters on Dec. 16.

The study is the first published research in the U.S. to investigate and document the use of brominated flame retardants in firefighter turnout gear, worn for protection on the job. The findings could inform fire department decision-making when it comes to keeping or replacing gear.

Structural firefighters — those working in the built environment — wear turnout gear consisting of three layers: a flame-resistant outer shell; a middle layer, called a moisture barrier, that shields against germs while providing breathability; and an inner layer to prevent overheating.

These protective qualities stem in part from chemical treatments added to the garments by manufacturers to meet rigorous standards developed by the National Fire Protection Association, according to lead author Heather Stapleton, Ronie-Richele Garcia-Johnson Distinguished Professor at Duke University’s Nicholas School of the Environment.

For several years, firefighters have been concerned about turnout gear treatments containing chemicals called PFAS, which confer oil and water resistance and sometimes flame resistance. Multiple human and animal studies have found associations between PFAS exposures and various health problems, including some cancers.

Although no studies have directly linked use of PFAS in turnout gear exposure to subsequent health risks in firefighters, gear manufacturers have been phasing out use of the chemicals. Additionally, several states have passed legislation that will prohibit the purchase of turnout gear treated with PFAS starting in 2027.

These actions have prompted questions about what other substances manufacturers might use in turnout gear. Companies do not typically disclose chemical ingredients in their treatments.  

“There was a rumor that one of the turnout gear manufacturers might be using brominated flame retardants in the non-PFAS treated textiles,” Stapleton said. “Because some brominated flame retardants have known toxicity, I requested a sample of the gear in question to test.’”

Brominated flame retardants are added to textiles and other products to reduce flammability. Exposure to the chemicals has been associated with negative health effects including cancer, thyroid disease and neurodevelopmental problems.

Stapleton’s informal experiment found evidence of brominated flame retardants in the turnout gear sample, spurring a more robust study with partners at North Carolina State University’s Wilson College of Textiles and the International Association of Fire Fighters. Their aim was to better understand the occurrence of PFAS and brominated flame retardants in gear manufactured in different years.

Peeling Back the Layers The researchers collected nine sets of used turnout gear produced between 2013 and 2020, and three sets from 2024 that were marketed as non-PFAS treated. Using two types of analyses, they tested each layer of gear for PFAS and brominated flame retardants. The analyses enabled them to determine the total amount of chemicals in the gear and the amounts that might rub off during wear — what they called “extractable” levels.

“We wanted to know which chemicals were intentionally applied during manufacturing, and we wanted to know what was likely to leach out over time, which could raise the risk of exposure through skin absorption or inhalation,” Stapleton said. 

As expected, the team detected PFAS in all sets of turnout gear manufactured between 2013 and 2020. However, turnout gear made in 2024 contained only low or non-detectable levels of extractable PFAS, indicating that the garments had not been treated with the chemicals, as the manufactures had indeed advertised. Rather, those minor amounts had likely glommed onto the garments from the surrounding environment during use, the authors noted.

Each set of turnout gear also showed evidence of brominated flame retardants, at extractable levels generally greater than those measured for PFAS.

The highest extractable concentrations of brominated flame retardants occurred in garments advertised as non-PFAS treated, especially in the moisture barrier. The finding suggests that manufacturers intentionally added brominated flame retardants to help pass the flammability standard, and likely to compensate for the loss of a certain PFAS previously used in moisture barriers, Stapleton said.

Of the brominated flame retardants identified, a chemical called decabromodiphenyl ethane, or DBDPE, occurred at the greatest extractable levels.

Although no studies have examined the health effects of DBDPE exposure in the U.S., according to the team, a 2019 study of workers at a chemical manufacturing plant in China found associations between exposure to DBDPE, changes in thyroid hormone levels and signs of thyroid disease.

“I was really surprised that the manufacturers used DBDPE in turnout gear,” Stapleton said. “It has similar properties as a toxic chemical called decaBDE that has been largely phased out globally, raising questions about its safety.”

For most of the turnout gear manufactured between 2013 and 2020, the outer shell contained greater extractable concentrations of brominated flame retardants than either the moisture barrier or the inner lining, likely reflecting accumulation from exposure to soot and smoke associated with fires, according to Stapleton.

“When building materials burn, they can release brominated flame retardants into the air that stick to gear and don’t wash out very well,” she explained.

However, the presence of brominated flame retardants in internal layers indicates that some manufacturers had been using these chemicals in turnout gear treatments for years, before PFAS were phased out of gear treatments, according to the authors.

Weighing the Costs Although firefighters’ specific exposure levels to these chemicals and the potential associated health effects have yet to be established, fire departments now have new data to consider when evaluating gear.

“Turnout gear is really expensive — one set costs thousands of dollars — and firefighters often use these garments for many years. Fire departments must consider both the financial and personal safety costs of keeping or replacing gear,” said coauthor R. Bryan Ormond, an associate professor at the Wilson College of Textiles and director of NC State’s Milliken Textile Protection and Comfort Center, who has studied trade-offs in gear performance.

According to Stapleton, some turnout gear suppliers have pivoted and are now selling garments untreated with PFAS or brominated flame retardants. To that end, she suggests fire departments advocate for more transparency about the chemical treatments used.

“We know firefighters receive higher exposure to multiple chemicals from all the hazards they face during their duty, and they shouldn’t have to worry about receiving additional chemical exposures from their gear,” said Stapleton, who also leads a study on cancer incidence in firefighters. “These first responders are a critically important component of our public safety and deserve to be respected and protected.”

Funding: This project was supported by the North Carolina Collaboratory at the University of North Carolina at Chapel Hill, with funding appropriated by the North Carolina General Assembly (to HMS and BO). HMS also wishes to thank Michael and Annie Falk for establishing the Falk Exposomics Laboratory.

END