Design considerations for protective boots for first responders to hazardous materials incidents.

First responder professionals are at high risk for work-related injuries (e.g., extreme temperatures, chemical and biological threats); boots are essential to ensure body protection since they have full contact with the ground in all scenarios. A substantial body of work has investigated the necessity of improvements in protective boots, but there is limited research conducted on boots with fit-adjustable fasteners for secure and adjustable fit within this context. Thus, this study explored the areas for improvement in boot design for the development of form-fitting and yet comfortable boots focusing on two different boot designs, prototype all-hazards tactical boots (lace-up) and rubber boots (slip-on). Findings indicated that the boot design should address participants' concerns with the material choices of boots, specifically with bulkiness, weight, and flexibility. Our findings provide insights into boot material and design choices to improve protective boots for first responders.

Criticism of Workplace Protection Barrier Face Covering Article Mischaracterizes ASTM Standard and its Potential Utility.

Editor's Note: This is a response to "Why a Workplace Barrier Face Covering is a Bad Idea" by Mark Nicas. DOI: 10.1177/10482911231193771.

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.

Feature, Barrier Face Coverings for Workers.

Face coverings have been recommended for the public and workers to prevent person-to-person transmission of COVID-19. Throughout 2020, guidelines for face coverings recommended multiple layers worn tightly against the face with straps or ear loops. This article briefly describes a new ASTM 3502 Standard Specification for Barrier Face Coverings (BFCs) and the development of performance criteria for workplace BFCs ahead of the Occupational Safety and Health Administration (OSHA) COVID-19 Emergency Temporary Standards (ETS). We also describe a method for comparing the effect on the time to receipt of an infectious dose (ID) of BFCs with varying degrees of inward leakage (personal protection) and outward leakage (source control). The role of BFCs in workplace settings during the pandemic and for exposure to infectious respiratory organisms after the pandemic remains in question. It will be important for occupational health and safety professionals to recognize their limitations in contrast with respiratory protection.

Do They Really Work? Quantifying Fabric Mask Effectiveness to Improve Public Health Messaging.

The purpose of this study is to compare masks (non-medical/fabric, surgical, and N95 respirators) on filtration efficiency, differential pressure, and leakage with the goal of providing evidence to improve public health messaging. Masks were tested on an anthropometric face filtration mount, comparing both sealed and unsealed. Overall, surgical and N95 respirators provided significantly higher filtration efficiency (FE) and differential pressure (dP). Leakage comparisons are one of the most significant factors in mask efficiency. Higher weight and thicker fabric masks had significantly higher filtration efficiency. The findings of this study have important implications for communication and education regarding the use of masks to prevent the spread of COVID-19 and other respiratory illnesses, specifically the differences between sealed and unsealed masks. The type and fabric of facial masks and whether a mask is sealed or unsealed has a significant impact on the effectiveness of a mask. Findings related to differences between sealed and unsealed masks are of critical importance for health care workers. If a mask is not completely sealed around the edges of the wearer, FE for this personal protective equipment is misrepresented and may create a false sense of security. These results can inform efforts to educate health care workers and the public on the importance of proper mask fit.

Survival of Staphylococcus aureus on the outer shell of fire fighter turnout gear after sanitation in a commercial washer/extractor.

BACKGROUND: Methicillin-resistant Staphylococcus aureus contamination on surfaces including turnout gear had been found throughout a number of fire stations. As such, the outer shell barrier of turnout gear jackets may be an indirect transmission source and proper disinfection is essential to reduce the risk of exposure to fire fighters. Cleaning practices vary considerably among fire stations, and a method to assess disinfection of gear washed in commercial washer/extractors is needed. METHODS: Swatches (1 in. ×  1.5 in.) of the outer shell fabrics, Gemini™, Advance™, and Pioneer™, of turnout gear were inoculated with S. aureus, and washed with an Environmental Protection Agency-registered sanitizer commonly used to wash turnout gear. To initially assess the sanitizer, inoculated swatches were washed in small tubes according to the American Society for Testing Materials E2274 Protocol for evaluating laundry sanitizers. Inoculated swatches were also pinned to turnout gear jackets and washed in a Milnor commercial washer/extractor. Viable S. aureus that remained attached to fabric swatches after washing were recovered and quantified. Scanning Electron Microscopy was used to characterize the stages of S. aureus biofilm formation on the swatches that can result in resistance to disinfection. RESULTS: Disinfection in small tubes for only 10 s reduced the viability of S. aureus on Gemini™, Advance™, and Pioneer™ by 73, 99, and 100%, respectively. In contrast, disinfection of S. aureus-contaminated Gemini™ swatches pinned to turnout gear and washed in the washer/extractor was 99.7% effective. Scanning Electron Microscopy showed that biofilm formation begins as early as 5 h after attachment of S. aureus. CONCLUSION: This sanitizer and, likely, others containing the anti-microbial agent didecyl dimethyl ammonium chloride, is an effective disinfectant of S. aureus. Inclusion of contaminated outer shell swatches in the wash cycle affords a simple and quantitative method to assess sanitization of gear by commercial gear cleaning facilities. This methodology can be extended to assess for other bacterial contaminants. Sanitizer-resistant strains will continue to pose problems, and biofilm formation may affect the cleanliness of the washed turnout gear. Our methodology for assessing effectiveness of disinfection may help reduce the occupational exposure to fire fighters from bacterial contaminants.

Occupational safety and health protections against Ebola virus disease.

Even as the Ebola epidemic is finally showing signs of remitting, controversy continues regarding the modes of disease transmission, the understanding of which necessarily dictates methods of prevention. The initial public health response to the epidemic was based on assumptions formed during previous outbreaks, and in the belief that transmission was restricted to direct "contact" with other infected patients. However, the current Ebola outbreak differed from previous experiences in its intensity of transmission, speed of spread, and fatality rate and was also particularly unforgiving on health workers occupationally infected. Even with these differences, however, other modes of transmission were not considered by public health authorities, thus denying both the hard-hit health worker populations and the wider public more protective guidance. International Labor Conventions require employers to provide a comprehensive safety program that anticipates work-related risks and specifies strategies for protection against them. Such a precautionary approach is recommended in future epidemic planning, especially where evidence regarding transmission is incomplete.

Effect of firefighters' personal protective equipment on gait.

The biomechanical experiment with eight male and four female firefighters demonstrates that the effect of adding essential equipment: turnout ensemble, self-contained breathing apparatus, and boots (leather and rubber boots), significantly restricts foot pronation. This finding is supported by a decrease in anterior-posterior and medial-lateral excursion of center of plantar pressure (COP) trajectory during walking. The accumulation of this equipment decreases COP velocity and increases foot-ground contact time and stride time, indicating increased gait instability. An increase in the flexing resistance of the boots is the major contributor to restricted foot pronation and gait instability as evidenced by the greater decrease in excursion of COP in leather boots (greater flexing resistance) than in rubber boots (lower resistance). The leather boots also shows the greatest increase in foot contact time and stride time. These negative impacts can increase musculoskeletal injuries in unfavorable fire ground environments.

A suggested approach to the selection of chemical and biological protective clothing--meeting industry and emergency response needs for protection against a variety of hazards.

The paper describes the development of a comprehensive decision logic for selection and use of biological and chemical protective clothing (BCPC). The decision logic recognizes the separate areas of BCPC use among emergency, biological, and chemical hazards. The proposed decision logic provides a system for type classifying BCPC in terms of its compliance with existing standards (for emergency applications), the overall clothing integrity, and the material barrier performance. Type classification is offered for garments, gloves, footwear, and eye/face protection devices. On the basis of multiple, but simply designed flowcharts, the type of BCPC appropriate for specific biological and chemical hazards can be selected. The decision logic also provides supplemental considerations for choosing appropriate BCPC features.

A comparative analysis of glove permeation resistance to paint stripping formulations.

Although there is a wide variety of work gloves available to users of commercial paint stripping products, there are no published studies examining which type of gloves provide the best protection. To address this need, a multiphase study was undertaken to evaluate how several types of gloves resist multichemical-based paint stripping formulations. Due to the wide range of commercial paint stripping formulations available, seven categories of surrogate paint stripper formulations were created to evaluate glove performance initially. Twenty different glove types were identified for initial evaluation. Degradation resistance screening was carried out for each glove style and paint stripping formulation. Screening results were used to identify those glove styles least affected by the surrogate paint strippers. Those gloves were then evaluated for their resistance to permeation using continuous contact testing based on ASTM Test Method F 739. Glove styles showing extensive permeation with early breakthrough were then evaluated to see how they performed with only intermittent contact with the surrogate paint strippers using a modified form of ASTM Test Method F 1383. These results were used to select glove styles to be tested using commercially available paint stripping products. Gloves made of plastic laminate and butyl rubber were the most effective against the majority of paint strippers. More glove styles resisted permeation by N-methylpyrrolidone and dibasic ester-based paint strippers than conventional solvent products such as methylene chloride, methanol, isopropanol, acetone, and toluene. The study also found that decreased contact time caused relatively little change in permeation resistance and that the surrogate paint stripper data did not always accurately predict resistance to the commercial paint stripper formulations.