Firefighters’ Clothing and Equipment: Performance, Protection, and Comfort PDF by Guowen Song, Faming Wang

Contents

Preface
Personal protective equipment (PPE) and textile-based equipment are critical for firefighters to ensure their safety and health. Ineffective protection at a fire scenario with multiple hazards can cause injury and fatality as well as potentially increase property damage and loss. Fire reports [1] confirm that in the past four decades in the United States about 68,000 firefighters received burn injuries with more than 60 fatalities each year. The best approach for firefighters to mitigate burn injuries and reduce risk of death from unpredictable hazards is to apply high-performance PPE.

Firefighters encounter complex environments and conditions while performing their duties within a wide range of possible hazards. Thermal exposure, which may result from radiation, convection, hot liquid, steam, and/or hot solids, is the primary possible hazard exposure for firefighters. During combustion of structural materials, firefighters can encounter thermal hazards including collapsing fireground debris, hot liquid, and molten materials. In a fire scene, cool water from a hose can quickly become hot water, and then steam. Steam and wet air cause more serious burns because more heat energy can be stored in water vapor than in dry air. On the other hand, in some geographic regions, severe winter weather with sub-zero temperatures poses cold injury threats such as frostbite to firefighters, especially when the PPE system gets wet by sweat or hose water.

Current firefighter protective ensembles are heavy and stiff and suffer from reduced vapor permeability, all of which increase physiological strain. Statistics showed that overexertion, physical and thermal stresses, and medical issues account for 42% of the main causes of deaths. PPE are engineered with not only increased thermal protection but also increased bulk and weight. This affects efficiency and mobility, increasing the metabolic cost of work by up to 50% [2].

Furthermore, the fabric thickness and moisture barrier layers restrict body heat dissipation and create additional undue heat stress. The heat generated from working muscles, as well as the heat transferred from the local environment, generate increased thermoregulatory strain, putting more demand on the cardiovascular system. Uncompensated heat strain will greatly affect the performance, function, and health of the firefighters.

The current system tends to store large amounts of thermal energy during exposure to fire hazards, and this amount of stored energy can be discharged to the skin. Studies [3–5] have demonstrated that stored thermal energy contributes significantly to skin burn injuries, specifically compression burns. As a result, firefighters’ arms and legs, knees, elbows, and shoulders, where SCBA (self-contained breathing apparatus) straps press the surrounding fabric against the skin, are vulnerable to burn injuries from stored energy discharge by compression.

This compress burn actually relates to another major issue of concern for firefighters on their ability to sense the heat of the fire. Additionally, existing product standards and testing protocols are not adequately developed to evaluate the risks caused by those hazards when combined with moisture on performance. During firefighting, protective clothing becomes wet from internal and external sources. At a high ambient temperature or during strenuous activity, the wearer perspires profusely, so clothing next to the skin becomes saturated with perspiration. Studies [6,7] show that the presence and distribution of moisture have a complex effect on heat transfer through insulating materials. In some occasions, if water vapor transfers to the human skin and condenses, steam burns may occur, as the water vapor also transfers the heat it absorbed to evaporate.

The core challenges for current PPE used for firefighters are the engineering and design of multifunctional performance for the high-level protection with minimum physiological burdens. The solution for this relies on the nextgeneration new textile materials, new discoveries on functional design and novel technology, as well as the understanding on mechanisms associated with heat and mass transfer in the human-clothing-environment system.

With this goal, we have developed this volume that presents an overview of the current state of understanding and knowledge for protective clothing and equipment, as well as issues and challenges associated with firefighter and other emergency first responders. This book includes 12 chapters and covers discussion on textile materials, clothing comfort and protective performance, human thermoregulation system, relevant methods and standards, instrumentation technologies for comfort and protection, 3D body scanning application, and human trials. In addition, future trends on smart firefighting clothing/equipment and numerical modeling and human skin burn are also presented.

We sincerely hope our efforts on this book will provide useful information and the present knowledge regarding hazards, firefighters, and protective clothing and equipment. This book may serve as a useful tool and technical source for scientists in textiles and clothing, mechanical engineering, and occupational safety and health. It is also our expectation that the book will provide a fundamental guide to educators, engineers, ergonomists, industrial hygienists, and designers in universities, research institutes, fire stations, and industrial companies. We would like to express our sincere appreciation to all the authors and guest reviewers who devoted considerable effort to this book. We would also like to extend our thanks to the production team at Taylor & Francis for their patience with the editors and authors.