Evaluation of the decontamination methods for turnout gear

Firefighters are exposed to various carcinogenic substances during firefighting tasks, but also in the maintenance of firefighting personal protective equipment (PPE). Due to multiple exposures to chemical agents via different exposure routes, the International Agency for Research on Cancer (IARC) categorized the firefighting occupation as Group 1 - carcinogenic to humans. Decontamination methods have been found to play an important role in reducing firefighter chemical exposures. Unfortunately, decontamination techniques are insufficient in removing carcinogenic substances from PPE. This study aimed to evaluate decontamination methods for firefighter turnout gear. Using various techniques, the cleaning efficiency of 18 polycyclic aromatic hydrocarbons (PAHs) from turnout gear coats contaminated during firefighting exercises was measured. For turnout gear coats (n = 40), decontamination methods used were conventional aqueous laundering (AL) and its combination with advanced hydrogen peroxide treatment (H₂O₂) or ozone treatment in a chamber (O₃). In addition, the cleaning efficiencies of advanced liquid carbon dioxide (LCO₂) and the ozone laundry system (LO₃) were measured. Results show that when the conventional AL water wash temperature increased from 40 to 60 °C, cleaning efficiencies did not significantly increase. Cleaning efficiencies in outer layers of coats were 63% and 60%, respectively. The results in outer layers of AL combined with O₃ and H₂O₂ techniques showed cleaning efficiencies 84% and 42%, respectively. Cleaning efficiency with LO₃ and with the fully advanced LCO₂ technique demonstrated cleaning efficiency 71% and 74%, respectively. LCO₂ was the most advanced, especially in the middle layers, yielding a cleaning efficiency of 84% while other techniques in the middle layers reached a maximum efficiency 24%. The cleaning efficiency of all methods indicated approximately 20-30% lower cleaning efficiency for high molecular weight (HMW) PAHs than for low molecular weight (LMW) PAHs. The results of this study emphasized the importance of improving conventional AL and the advantage of the LCO₂ method in enhancing cleaning efficiency.