Environmental Forensic Investigation of PFAS Exposure from Firefighter Turnout Gear
Project Overview
RoseyFields conducted a comprehensive environmental forensic investigation to evaluate occupational exposure to per- and polyfluoroalkyl substances (PFAS) associated with structural firefighter turnout gear. The project integrated environmental chemistry, industrial hygiene, analytical chemistry, exposure science, toxicology, and quantitative risk assessment to evaluate whether prolonged use of PFAS-containing turnout gear could result in meaningful occupational exposure through dermal contact and incidental ingestion. The investigation was performed in support of complex environmental litigation involving firefighter turnout gear manufacturers and suppliers and included evaluation of product design, chemical composition, exposure pathways, and human health risk.
The investigation focused on the role of firefighter protective clothing as a long-term reservoir of PFAS compounds intentionally incorporated into moisture barriers, outer shell materials, and other performance fabrics to improve water resistance, oil repellency, durability, and thermal protection. RoseyFields evaluated how repeated occupational use, environmental weathering, abrasion, and routine handling influence the migration of PFAS from turnout gear to firefighters during normal work activities. The project further examined the scientific literature describing contaminant transfer from treated surfaces to skin, dermal absorption of PFAS, incidental hand-to-mouth ingestion, and the cumulative effects of repeated occupational exposure over the course of a firefighting career.
A principal objective of the investigation was to develop a scientifically defensible exposure assessment that integrated laboratory analytical results, peer-reviewed transfer efficiency studies, occupational work practices, and established environmental health guidance. By combining forensic sampling, analytical chemistry, exposure modeling, and toxicological evaluation, RoseyFields reconstructed realistic occupational exposure scenarios representative of long-term structural firefighting operations.
Chemicals of Concern
The investigation focused on per- and polyfluoroalkyl substances historically used in firefighter protective clothing and associated performance textiles. Primary chemicals of concern included perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorobutane sulfonate (PFBS), fluorotelomer compounds, and additional PFAS analytes included within EPA Method 1633. Because many fluorinated polymers and precursor compounds may degrade over time or contain residual manufacturing contaminants, the investigation evaluated both measurable PFAS residues and fluorinated materials capable of contributing to long-term occupational exposure.
The project also considered the persistence of PFAS within turnout gear throughout its service life. Mechanical wear, repeated flexing, environmental weathering, laundering, and fireground use were evaluated as factors influencing contaminant migration from protective fabrics to skin-contact surfaces and surrounding environments.
Methods
RoseyFields developed a comprehensive forensic sampling and exposure assessment protocol for evaluating PFAS contamination within firefighter turnout gear. Representative samples were collected from exterior shell materials, interior liners, gloves, boots, jackets, and pants using documented chain-of-custody procedures to preserve sample integrity throughout collection, transport, and laboratory analysis. Sampling locations were selected to evaluate both external contamination and PFAS migration into interior surfaces likely to contact firefighters during routine use. Analytical testing was performed using EPA Method 1633 to quantify forty individual PFAS analytes across multiple components of structural firefighting ensembles.
Following laboratory analysis, RoseyFields integrated measured PFAS concentrations with peer-reviewed literature describing object-to-hand transfer efficiencies, hand-to-mouth transfer mechanisms, dermal absorption, and occupational exposure factors. Published transfer efficiency studies involving treated surfaces, textiles, consumer products, and occupational materials were reviewed to develop scientifically supported exposure assumptions representative of repeated firefighter contact with turnout gear. Transfer coefficients were selected using conservative methodologies consistent with published environmental health literature and regulatory guidance.
The investigation further incorporated exposure factors describing duration of gear use, frequency of occupational contact, skin surface area, hand-to-mouth activity, and long-term career exposure. Upper confidence limit calculations were performed using accepted environmental statistical methods to estimate representative contaminant concentrations for exposure modeling while minimizing uncertainty associated with individual analytical measurements. Dermal exposure estimates and incidental ingestion doses were subsequently evaluated using established U.S. Environmental Protection Agency exposure assessment methodologies together with published toxicity values for PFAS compounds.
In addition to laboratory testing and exposure modeling, RoseyFields reviewed occupational histories, deposition testimony, firefighting practices, manufacturer information, applicable National Fire Protection Association standards, and peer-reviewed scientific literature describing PFAS incorporation into turnout gear. These multiple lines of evidence were integrated into a comprehensive conceptual exposure model describing contaminant migration from manufacturing through occupational contact and eventual human exposure.
Results
The investigation demonstrated that structural firefighter turnout gear functions as a persistent reservoir of PFAS capable of producing repeated occupational exposure throughout the normal service life of the equipment. Laboratory analyses identified measurable PFAS residues on multiple components of turnout gear, including exterior shell materials, interior liners, gloves, boots, jackets, and pants. The distribution of detected PFAS was consistent with intentional incorporation of fluorinated materials during manufacturing rather than isolated environmental contamination.
Evaluation of contaminant transfer mechanisms demonstrated that firefighters experience multiple simultaneous exposure pathways during routine use of turnout gear. Repeated donning and doffing of protective clothing, prolonged dermal contact during emergency response, elevated skin temperature, perspiration, abrasion, and frequent handling of contaminated equipment all contribute to transfer of PFAS residues from turnout gear to the skin. Published object-to-hand transfer studies further demonstrate that contaminants present on treated surfaces may efficiently transfer to skin under both dry and moist contact conditions, providing a scientifically supported basis for evaluating occupational PFAS exposure.
The investigation also determined that incidental ingestion represents an important secondary exposure pathway. Firefighters frequently handle equipment, food, beverages, radios, tools, and personal protective equipment during extended emergency operations and station activities. Established hand-to-mouth exposure methodologies developed by the California Office of Environmental Health Hazard Assessment provide a scientifically accepted framework for estimating contaminant transfer from occupational surfaces to the mouth following repeated handling events. Integration of measured PFAS concentrations with published transfer efficiencies allowed estimation of cumulative ingestion doses associated with long-term occupational use of turnout gear.
The combined exposure assessment demonstrated that dermal absorption and incidental ingestion together may contribute to meaningful cumulative PFAS exposure over the course of a firefighting career. Statistical evaluation using upper confidence limit concentrations, conservative exposure assumptions, and accepted toxicity values indicated that long-term occupational exposure substantially exceeded commonly accepted environmental risk benchmarks, supporting the conclusion that firefighter turnout gear represents a significant and scientifically credible source of PFAS exposure in occupational settings.
Conclusions
This investigation demonstrates the importance of integrating environmental forensics, analytical chemistry, industrial hygiene, toxicology, exposure science, and quantitative risk assessment when evaluating occupational exposure to PFAS from firefighter protective equipment. Rather than relying solely on the presence of PFAS within turnout gear, the investigation reconstructed complete exposure pathways by combining laboratory analytical data with established contaminant transfer mechanisms, dermal absorption science, and human exposure modeling.
The project further demonstrates that firefighter turnout gear may function as a long-term source of occupational PFAS exposure through repeated dermal contact and incidental ingestion during routine firefighting operations. The use of documented chain-of-custody procedures, EPA Method 1633 laboratory analyses, peer-reviewed transfer efficiency studies, statistical exposure modeling, and established regulatory methodologies provided a scientifically robust framework for evaluating cumulative occupational exposure over an extended firefighting career.
This investigation was conducted under the direction of Dr. Paul Rosenfeld, an environmental scientist and environmental forensic expert with extensive experience in PFAS chemistry, occupational exposure assessment, industrial hygiene, environmental toxicology, contaminant transfer modeling, and human health risk assessment. Through RoseyFields LLC, Dr. Rosenfeld provides technical evaluation of PFAS-containing products, occupational exposure reconstruction, environmental forensic investigations, contaminant fate and transport analysis, exposure modeling, regulatory review, and expert witness services involving firefighter exposures, consumer products, and emerging contaminants.
References
California Office of Environmental Health Hazard Assessment (OEHHA). Proposition 65 Interpretive Guideline No. 2011-001: Guideline for Hand-to-Mouth Transfer of Lead through Exposure to Consumer Products. May 2011.
Cohen Hubal, E. A., Sheldon, L. S., Burke, J. M., McCurdy, T. R., Berry, M. R., Rigas, M. L., Zartarian, V. G., & Freeman, N. C. G. Children’s Exposure Assessment: Transfer Efficiency of Contaminants from Surfaces to Skin.
Cohen Hubal, E. A., et al. Transfer Efficiency of Residues from Surfaces to Human Skin Under Dry and Moist Conditions.
Greene, C., et al. Fomite-to-Finger Transfer Efficiency During Repeated Contact Events.
U.S. Environmental Protection Agency. Method 1633: Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous, Solid, Biosolids, and Tissue Samples.
RoseyFields LLC. Expert Report on Occupational Exposure to Per- and Polyfluoroalkyl Substances (PFAS) from Firefighter Turnout Gear.
RoseyFields LLC. Firefighter Turnout Gear Sampling Plan and Analytical Methodology.