Analyzing PFAS in Firefighter Gear

In a recent study led by scientists from the Environmental Health Science and Research Bureau in Ottawa, Canada, thermal desorption (TD) and gas chromatography– time-of-flight mass spectrometry (GC×GC-TOFMS) were used to track per- and polyfluoroalkyl substances (PFAS) emissions from materials used in firefighter gear. Their findings were published in the Journal of Chromatography A (1).

Firefighter helmet and protection gears | Image Credit: © Firefighter Montreal - stock.adobe.com

Per- and polyfluoroalkyl substances (PFAS) are complex groups of synthetic chemicals that have been used in consumer products since the 1950s. These chemicals are present in non-stick cookware, stain resistant material, and firefighting foam, and more. According to the CDC, using data from the National Health and Nutrition Examination Survey (NHANES), 97% of Americans were found to have PFAS in their blood. Further, PFAS and their degradation products are pollutants that are challenging to remove from the environment and are highly mobile once released. PFAS have been linked to adverse health effects, such as developmental and reproductive toxicity, immune system disruption, and cancer.

Assessing occupational exposure to PFAS can be challenging due to its widespread use and diverse applications. Among susceptible populations, firefighters are especially high-risk, since they are regularly exposed to an array of toxic chemicals such as combustion products and aqueous film forming foam used as a suppressant. A recent investigation showed that each layer of firefighters' turnout gear contains a higher proportion of volatile PFAS than non-volatile PFAS, namely fluorotelomer alcohols (FTOHs) and fluorotelomer acrylates (FTAc) (3). Further, other functional textiles treated with fluorinated polymers for weather resistance also emit volatile PFAS when exposed to rain, sun, and domestic washing. This hints that firefighters may be routinely exposed to PFAS, though to what extent remains unknown.

Comprehensive two-dimensional gas chromatography (GC×GC), when coupled with time-of-flight mass spectrometry (TOFMS), offers the advantage of acquiring high resolution full mass range spectra at high acquisition speeds. This makes the combination suitable for non-targeted screening applications, though its potential for analyzing to volatile PFAS emission in functional textiles remains largely unexplored. In this study, the scientists reported the emission of PFAS from three firefighter turnout gear jackets at 38 °C. Volatile emissions from the three layers (outer layer, moisture barrier, and thermal liner) of the gear were collected onto sorbent tubes via dynamic headspace sampling using a micro-scale chamber device kept at 38 °C for one hour. The emission was characterized using thermal desorption (TD) coupled to GC×GC–TOFMS.

With TD-GC×GC–TOFMS, the scientists successfully extracted, separated, and identified PFAS and other volatile organic compounds (VOCs) from the functional textiles of firefighter turnout gear. The resulting chromatograms had structured ordering, enabling PFAS to elute as a distinct band, well-separated from other matrix interferences. A second filtering using the fragment ions typical of PFAS, CF₃ (m/z 69), C₃H₂F₃ (m/z 95) and C₃F₅ (m/z 131), allow further confidence in PFAS assignment. Additionally, the comprehensive nature of GC×GC–TOF MS provided non-targeted screening of the entire sample, enabling other compounds of concern to be monitored. and tentatively identified using the NIST23 database. The PFAS emitted from the fabrics showed trends related to how worn the gear was and what layers they stemmed from.

Overall, this study highlighted the importance of further understanding volatile emissions from functional textiles and other textiles treated with polymeric PFAS. Understanding exposure pathways will allow for the development of effective exposure mitigation strategies, all while informing disposal and management practices for PFAS-containing textiles to minimize their environmental impact.

References

(1) Aranda-Rodriguez, R.; Piperakis, A.; Grandy, J.; McGregor, L.; et al. PFAS Emissions from Functional Textiles Using Micro-Chamber and Thermal Desorption Coupled to Two-Dimensional Gas Chromatography-Time of Flight Mass Spectrometry (TD-GC×GC-TOFMS). J. Chromatogr. A 2024, 465219. DOI: 10.1016/j.chroma.2024.465219

(2) Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS). National Institute of Environmental Health Sciences 2024. https://www.niehs.nih.gov/health/topics/agents/pfc (accessed 2024-8-6)

(3) Muensterman, D. J.; Titaley, I. A.; Peaslee, G. F.; Minc, L. D.; et al. Disposition of Fluorine on New Firefighter Turnout Gear. Environ. Sci. Technol. 2022, 56 (2), 974–983. DOI: 10.1021/acs.est.1c06322