Rinsing Aircraft Hangar Fire Suppression System Components Contaminated With PFAS: Analysis of Rinse Waters and Pipe Surfaces.

This study examined PFAS persistence on plumbing components obtained from a retired aircraft hangar. The effect of rinse volume and pipe corrosion was investigated to address technical gaps and inform practical solutions for PFAS-impacted fire suppression systems. The components, rinsed with deionized water, included straight pipe sections as well as elbows and proportioners. Solid-phase extraction with HPLC/MS/MS was employed to analyze PFAS in the rinse waters. Straight pipe sections followed trends for PFAS persistence reported in the literature for such sections, and the results for elbows and proportioners, not previously reported, suggested meaningful differences compared to straight sections. Results indicate that a single rinsing cycle consisting of three volumes of deionized water is capable of partially removing PFAS and that the amount of PFAS removed by successive rinses decreases with each rinse. Pre- and post-rinse pipe specimens were analyzed using a scanning electron microscope (SEM) coupled with energy dispersive X-ray spectroscopy (EDS). Corrosion of the components impacts desorption, potentially due to a weakly bound layer on the surface and a strongly bound layer interacting with metal oxides. These results inform future research and decontamination protocols needed for remediating firefighting infrastructure contaminated with PFAS.