E2: Research Roundup Hazard Recognition/Exposure Assessment 2

A chemical assessment strategy is presented to evaluate firefighter exposure to known or suspected carcinogenic compounds associated with firefighting. A case study is presented focused on potential extended exposures due to PPE, work practices, hygiene, and ventilation of firefighter facilities. 

During the COVID-19 pandemic, there was a shortage of surgical masks and N95® filtering facepiece respirators. The general public resorted to employing various types of masks for source control with the level of personal protection being unknown. It became imperative to gain an understanding of the effectiveness of such masks when utilized as source control products. The objective of this study was to quantify total outward leakage (TOL) of masks in nine categories: (1-3) Level 1, 2, and 3 masks compliant with ASTM F 2100; (4) single-layer cloth masks; (5 - 6) multilayer cloth masks with and without a high-efficiency particulate air (HEPA) filter; (7 - 8) multilayer cloth masks with and without a particulate matter (PM) 2.5 filter; and (9) three-layer nonwoven masks for nonmedical use. A benchtop testing system was devised to assess two models from each mask category. Each mask was placed onto two sizes (medium and large) of headforms with a silicone elastomer artificial skin. Mask type and headform size were found to have a significant effect (P-Value <0.05) on the TOL. This study provided evidence supporting the selection of masks as effective source control measures for the general public. Moreover, the incorporation of standardized specifications for cloth masks could be used as requisite for individuals with diverse facial dimensions.