Evaluating the performance of surfactant and charcoal-based cleaning products to effectively remove PAHs from firefighter gear.

Firefighters regularly respond to fire scenes where a mixture of chemicals including volatile, semi-volatile, and nonvolatile compounds are present in smoke and soot. Polycyclic aromatic hydrocarbons (PAHs) are common contaminants at fire scenes that may be deposited on the gear and the individual firefighter. Laundering is a common approach for the decontamination of contaminated gear. Surfactants are widely used by firefighters during laundering to remove PAHs as they are generally non-toxic and biodegradable. The removal of PAHs depends on the surfactant types, chemistries, and concentrations. This study evaluated the effect of surfactant concentrations to remove persistent contaminants like PAHs from turnout gear. The cleaning performance of different types of surfactants was also evaluated. Outer shell fabrics were contaminated with a standard mixture of 16 PAH compounds, and two commercial detergents were used at different concentrations. Additionally, the cleaning efficacy of eight commercially available regular and charcoal-based cleaning products was also determined against PAHs at a single surfactant concentration. For the decontamination method, a bench-scale washing procedure simulating the National Fire Protection Assocation 1851 laundering process was used. The removal efficacy of high molecular weight (HMW) PAHs were found to be lower compared to the low molecular weight PAHs for any type or any concentration of detergent. Our research also showed that the recommended surfactant concentrations provided by detergent manufacturers can be ineffective at removing the HMW PAHs from heavily contaminated fabric. With 1mL of detergent in a 100-mL bath, which is multiple times higher than recommended amount, only 40% of HMW PAHs were removed. The cleaning efficacy can be increased to above 90% by using higher concentrations of detergents. This research shows that firefighters may need to use a higher concentration of detergent than the recommended amount to effectively remove PAHs from the gear. All the regular and charcoal-based detergents were able to remove PAHs effectively from contaminated fabrics when a higher concentration of detergent was used.

Firefighters' exposure to per-and polyfluoroalkyl substances (PFAS) as an occupational hazard: A review.

The term "firefighter" and "cancer" have become so intertwined in the past decade that they are now nearly inseparable. Occupational exposure of firefighters to carcinogenic chemicals may increase their risk of developing different types of cancer. PFAS are one of the major classes of carcinogenic chemicals that firefighters are exposed to as occupational hazard. Elevated levels of PFAS have been observed in firefighters' blood serum in recent studies. Possible sources of occupational exposure to PFAS include turnout gear, aqueous film-forming foam, and air and dust at both the fire scene and fire station. Preliminary discussion on PFAS includes definition, classification, and chemical structure. The review is then followed by identifying the sources of PFAS that firefighters may encounter as an occupational hazard. The structural properties of the PFAS used in identified sources, their degradation, and exposure pathways are reviewed. The elevated level of PFAS in the blood serum and how this might associate with an increased risk of cancer is discussed. Our review shows a significant amount of PFAS on turnout gear and their migration to untreated layers, and how turnout gear itself might be a potential source of PFAS exposure. PFAS from aqueous film-forming foams (AFFF), air, and dust of fire stations have been already established as potential exposure sources. Studies on firefighters' cancer suggest that firefighters have a higher cancer risk compared to the general population. This review suggests that increased exposure to PFAS as an occupational hazard could be a potential cancer risk for firefighters.

Toward the future of firefighter gear: Assessing fluorinated and non-fluorinated outer shells following simulated on-the-job exposures.

In 2022, the occupation of firefighting was categorized as a "Group 1" carcinogen, meaning it is known to be carcinogenic to humans. The personal protective equipment that structural firefighters wear is designed to safeguard them from thermal, physical, and chemical hazards while maintaining thermo-physiological comfort. Typically, the outer layer of structural turnout gear is finished with a durable water and oil-repellent (DWR) based on per- and polyfluoroalkyl substances (PFAS) that helps limit exposure to water and hazardous liquids. The PFAS-based aqueous emulsion typically used in DWR finishes is highly persistent and can cause various health problems if absorbed into the body through ingestion, inhalation, and/or dermal absorption. In response, the U.S. Fire Service has begun using non-PFAS water repellants in firefighter turnout gear. This study aims to evaluate the performance of both traditional PFAS-based and alternative non-PFAS outer shell materials. The study involved exposing both PFAS-based and non-PFAS DWR outer shell materials in turnout composites to simulated job exposures (i.e., weathering, thermal exposure, and laundering) that artificially aged the materials. After exposures, samples were evaluated for repellency, durability, thermal protection, and surface chemistry analysis to determine any potential performance trade-offs that may exist. Non-PFAS outer shell fabrics were found not to be diesel/oil-repellent, posing a potential flammability hazard if exposed to diesel and subsequent flame on an emergency response. Both PFAS-based and non-PFAS sets of fabrics performed similarly in terms of thermal protective performance, tearing strength, and water repellency. The surface analysis suggests that both PFAS and non-PFAS chemistries can degrade and shed from fabrics during the aging process. The study indicates that firefighters should be educated and trained regarding the potential performance trade-offs, such as oil absorption and flammability concerns when transitioning to non-PFAS outer shell materials.

Effects of firefighting hood design, laundering and doffing on smoke protection, heat stress and wearability.

Firefighter hoods must provide protection from elevated temperatures and products of combustion (e.g. particulate) while simultaneously being wearable (comfortable and not interfering with firefighting activities). The purpose of this study was to quantify the impact of (1) hood design (traditional knit hood vs particulate-blocking hood), (2) repeated laundering, and (3) hood removal method (traditional vs overhead doffing) on (a) protection from soot contamination on the neck, (b) heat stress and (c) wearability measures. Using a fireground exposure simulator, 24 firefighters performed firefighting activities in realistic smoke and heat conditions using a new knit hood, new particulate-blocking hood and laundered particulate-blocking hood. Overall, soot contamination levels measured from neck skin were lower when wearing the laundered particulate-blocking hoods compared to new knit hoods, and when using the overhead hood removal process. No significant differences in skin temperature, core temperature, heart rate or wearability measures were found between the hood conditions. Practitioner Summary: The addition of a particulate-blocking layer to firefighters' traditional two-ply hood was found to reduce the PAH contamination reaching the neck but did not affect heat stress measurements or thermal perceptions. Modifying the process for hood removal resulted in a larger reduction in neck skin contamination than design modification. Abbreviations: ANOVA: analysis of variance; B: new particulate-blocking hood and PPE (PPE configuration); FES: fireground exposure simulator; GI: gastrointestinal; K: new knit hood and PPE (PPE configuration); L: laundered particulate-blocking hood and PPE (PPE configuration); LOD: limit of detection; MLE: maximum likelihood estimation; NFPA: National fire protection association; PAH: polycyclic aromatic hydrocarbon; PPE: personal protective equipment; SCBA: self-contained breathing apparatus; THL: total heat loss; TPP: thermal protective performance.

Headspace sampling-gas chromatograph-mass spectrometer as a screening method to thermally extract fireground contaminants from retired firefighting turnout jackets.

Firefighters are at a 1.5 to 2 times greater risk of contracting certain types of cancers as compared to the general population. After preliminary studies, it was evident that contaminated turnout gear and ensemble elements could be linked to heightened cancer rates amongst firefighters. Compounds such as polycyclic aromatic hydrocarbons (PAHs), perfluorinated compounds, phenols, phthalates, brominated flame retardants, dioxins, volatile organic compounds, and many others are present in the contaminated gear, of which many are known carcinogens. A setup of headspace sampler-gas chromatograph-mass spectrometer was used to measure the off-gassing of the fabric samples taken from retired field-contaminated turnout jackets. The fabric samples were exposed to a specific temperature and allowed to equilibrate for a fixed time in the HS. A custom reference mix of phenols, phthalates and PAHs was put together to develop standard calibration curves. The compounds off-gassing from the outer shell, thermal liner and the moisture barrier were analyzed and the masses of certain marker compounds were calculated based of the standard calibration curves. The technique could be used as a screening method to thermally extract contaminants from field-contaminated firefighter turnout materials such as jackets, pants, gloves, and so on.

Development of a Headspace Sampling-Gas Chromatography-Mass Spectrometry Method for the Analysis of Fireground Contaminants on Firefighter Turnout Materials.

Firefighting is classified as a 2B-possibly carcinogenic profession by the International Agency for Research on Cancer (IARC). Firefighters are exposed to a host of toxic fireground contaminants such as phenols, phthalates, and polycyclic aromatic hydrocarbons (PAHs), many of which are potentially carcinogenic. Studies show that the exposure to contaminated firefighter gear postfire poses a health risk to the firefighters. This study focused on the issue of contaminants being present on the gear and developing a thermal extraction method to perform the assessment. A headspace sampler (HS) connected to a gas chromatography-mass spectrometry (GC-MS) system was used to thermally extract known fireground contaminants and understand the effect of equilibration time and temperature on the thermal extraction efficiencies. The outer shell fabric samples (PBI/Kevlar blend) were spiked with known amounts of fireground chemicals, heated at various temperatures (36, 50, 100, and 200 °C), and analyzed using the developed method to calculate extraction efficiencies. This study is one of the first to utilize the all-in-one HS-GC-MS instrument to analyze the thermal extraction of a variety of fireground contaminants relative to different temperatures from firefighter gear materials. Based on the conditions evaluated, the results indicate that the 200 °C condition allowed for the maximum thermal extraction of contaminants from the outer shell material. The data collected from this study pave a way of creating a new method for the analysis of volatile and semivolatile contaminants from field-contaminated firefighter turnout material using HS-GC-MS.