Thermal Protective Clothing for Firefighters

Guowen Song, Sumit Mandal, René Rossi

• Publisher: Woodhead Publishing
• Year: 2016
• Print ISBN: 9780081012857
• eBook ISBN: 9780081012864
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

Thermal Protective Clothing for Firefighters explores the materials, design, and usage of thermal protective clothing. The characteristics of fire hazards are discussed in detail, and the thermal environments faced by firefighters in these fire hazards are also examined. The different types of potential burn injuries and the heat stress that occurs to firefighters' bodies when exposed to such thermal environments are analyzed. Furthermore, the development of various high performance fibers and fabrics for thermal protective clothing is discussed. The test methods and existing standards to evaluate the thermal protective and physiological comfort performances of the fabrics and clothing are critically reviewed. Recent developments in the field of fire- and heat-resistant materials have led to significant improvements in thermal protective clothing. In parallel with this, the complexity and risk levels of fires, especially in industrial-storage facilities, and developments in health and safety cultures have increased the demand for high-performance heat- and flame-resistant clothing and equipment, designed to mitigate skin burn injuries and reduce risk of death from fire hazards. Throughout the work, the gaps and limitations in existing test methods and standards are identified, and approaches are recommended for the development of enhanced test methods. Scenario modeling and its implications for firefighters' protective clothing is discussed, and various factors affecting performance are established. Finally, various key issues related to thermal protective clothing are addressed to guide the future research in the field of thermal protective clothing for firefighters. This book will help materials-textile engineers to develop high performance thermal protective clothing that can enhance the protection, safety, and comfort of firefighters. - Offers a helpful guide to the successful specification and design of high performance protective clothing to meet the high standards of today's regulatory framework - Introduces the new materials technical innovations that are transforming fire protective clothing - Explores the role of clothing from the operational perspective, including technical innovations - Offers a critical review of the test methods and existing standards to evaluate the thermal protective and physiological comfort performances of the fabrics and clothing

1

Introduction

Abstract

Clothing functions (eg, regular clothing, specialized protective clothing) are introduced with an emphasis on thermal protective clothing for firefighters. It has been stated that uncontrolled fires may occur in different places, such as natural areas, structural buildings, and vehicles. As firefighters always work in these uncontrolled fire-hazard areas, it is necessary to develop a thorough knowledge of thermal protective clothing for the safety of firefighters. This chapter briefly highlights the different types fabrics that are usually used in thermal protective clothing. The test standards for evaluating the thermal protective and physiological performances of these fabrics and clothing are presented. Additionally, different research on modeling and factors related to the performance of thermal protective clothing are highlighted.

Keywords

Regular clothing; Protective clothing; Thermal protective clothing; Firefighters; Thermal protective performance; Physiological performance; Modeling; Clothing performance factors

Clothing is not only one of the fundamental needs of all human beings; it is considered an extension of wearers' bodies, as a kind of “second skin.” Although clothing can impart psychological comfort to wearers in terms of adornment and social status, its primary role is to act as a barrier between wearers and their ambient environments, providing thermal and weather protection as well as physical comfort [1,2]. Along with these benefits, clothing can also aid wearers physiologically [3]: the balance between wearers' metabolic heat and its dissipation to their ambient environments (through dry heat loss or sweat evaporation) is maintained (within a tolerance limit) by controlling the features of clothing (eg, fiber and fabric, clothing design, and fit).

It is well established that regular clothing can effectively provide psychological, physical, and physiological comfort to wearers in a natural ambient environment (cold, temperate, or warm) [2]. However, this type of clothing is unsuitable for wearers who usually work in perilous ambient environments [4]. With the advancement of technology, the risk of human exposure to a variety of occupational hazards (chemical, biological, nuclear, mechanical, and thermal) has increased. For example, workers in various industrial sectors such as pharmaceutical, petrochemical, fertilizer, and nuclear energy may get exposed to chemical, biological, and nuclear hazards; some government personnel (eg, defense, police, military) may get exposed to mechanical hazards such as bullets or knives; and firefighters may potentially be exposed to thermal hazards such as flame, radiant heat, hot surfaces, hot liquids, and steam. In order to provide additional protection from these occupational hazards, varieties of specialized protective clothing have been developed, and are widely used by workers in the industrial and government sectors. This specialized protective clothing can be categorized as chemical protective clothing, biological (microbial) protective clothing, nuclear protective clothing, puncture- or cut-resistant (bullet-/knife-proof) protective clothing, and thermal (flame and radiant heat) protective clothing [5]. Among these types of specialized protective clothing, thermal protective clothing has a particular significance. This is because fire remains an integral part of our daily lives; thus, the probability of occurrence of a fire hazard is high. In the event of such fire hazards, efficient fire suppression by firefighters is very important to minimize human and economic loss. Effective thermal protective clothing is thus crucial for the safety of firefighters [6].

1.1 A brief background on thermal protective clothing for firefighters

In general, uncontrolled fires are likely to occur in three spaces: natural areas, structural buildings, and vehicles [7]. These uncontrolled fires occur through ignition of a single, or combination of different, combustible materials and substances, such as wood, polymers, oil, gas, and so on. The burning of these substances rapidly spreads the fire from its source to the surrounding area through nearby combustible substances. Such uncontrolled fires are very devastating and may destroy property, human lives and, depending on location, millions of acres of forest. Sometimes, the aftereffects of such uncontrolled fires are worse than the actual fires, especially when a heavy rainfall occurs. This situation may cause landslides, ash flow, and flash flooding, which could cause additional property damage and affect the residential water supply [8].

Many fire extinguishers, namely water (H₂O), foam, and carbon dioxide (CO₂), are used to quench uncontrolled fires. The immediate application of such extinguishers could quickly suppress uncontrolled fires, and the proper application of fire extinguishers demands trained personnel [9]. For this, firefighting training schools have been established. The prime job of firefighters is to immediately extinguish an uncontrolled fire at its source. Additionally, they need to rescue property and fire victims from the site of a fire. To accomplish these tasks, firefighters have to face thermal environments. These thermal environments can be categorized based on the intensity (routine, hazardous, and emergency) and type of exposures such as radiant heat, flame, hot surface, molten substances, hot liquids, and steam [10,11]. Firefighters work in thermal environments with varying intensities and exposures and statistics from the National Fire Protection Association (NFPA) have indicated that nearly 45,000 firefighter burn injuries and 100 firefighter fatalities occurred in the United States from 1981 to 2013 [12,13].

In order to mitigate firefighter burn injuries or fatalities, high-performance materials have been developed. Using these materials, various personal protective equipment (PPE), such as thermal protective clothing, footwear, and self contained breathing apparatus (SCBA) have been developed and are widely used in the industry. This PPE provides protection from burn injuries, inhaling harmful gases, and so on. Thermal protective clothing has been thoroughly tested to help reduce firefighters' burn injuries and/or fatalities by protecting them from exposed thermal environments, as well as transmitting their metabolic heat and sweat-vapor to the ambient environment (Fig. 1.1) [5,14,15]. As one of the prime key components for clothing is textile fibers, a need has been identified for constant development of fire-retardant/resistant textile fibers to develop high-performance thermal protective clothing [4,16,17].

Fig. 1.1 The purpose of thermal protective clothing.

Fire-retardant fibers are developed through chemical treatment or modification of commonly used natural or synthetic textile fibers such as cotton, wool, polyester, and so on [4,16,17]. Initially, these chemically treated fire-retardant fibers (cotton or wool) were widely used; later, inherently fire-resistant fibers became very popular to provide better protection for firefighters. Different types of inherently fire-resistant synthetic fibers [eg, aramid (eg, Nomex, Kevlar), polyamide-imide (eg, Kermel), polyimide (eg, P84 from Lenzing), and polybenzimidazole (eg, PBI)] were invented in the last few decades [18,19]. The chemically treated, fire-retardant fibers are mostly used for the manufacturing of thermal protective clothing for firefighters who work with outdoor or vehicle fire hazards, whereas, the inherently fire-resistant fibers are used to manufacture the thermal protective clothing for firefighters who work in structural building fire hazards. It has been hypothesized that fire-retardant/resistant fiber–based fabrics developed through the application of innovative approaches and technologies may lead to the development of high-performance thermal protective clothing for better protection of firefighters [20,21].

It has been further observed that the currently existing fire-resistant/retardant fabrics comprise a wide range of thermal stability and insulation characteristics. Therefore, it becomes essential to evaluate the softening/melting temperature of fibers used in the fabrics, the flammability of these fibers/fabrics, and the thermal protective performance of these fabrics in the laboratory before employing them to manufacture the thermal protective clothing. To evaluate the performance of thermal protective fabrics as well as the manufactured clothing, many researchers conducted the laboratory tests (bench-scale or full-scale manikin) according to various standard methods established by different organizations, such as the ASTM (American Society for Testing and Materials), NFPA (National Fire Protection Association), ISO (International Organization for Standardization), CEN (European Committee for Standardization), and CGSB (Canadian General Standard Board) [22–25].

Conventionally, simple bench-scale tests were used to evaluate the thermal protective performance of a fabric under laboratory-simulated thermal exposures with varying intensities [22,26,27]. After World War II, the evaluation of thermal protective performance of clothing became a requirement in military operations. Therefore, in the last few decades, instrumented full-scale manikin tests and standards have been developed to evaluate the thermal protective performance of clothing, and these are now being widely used within scientific communities [15,23]. In both of these types of laboratory tests, it is challenging to accurately simulate thermal environments faced by firefighters. Furthermore, a g...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Preface
• Woodhead Publishing Series in Textiles
• 1: Introduction
• 2: Fires and thermal environments
• 3: Skin burn injuries and heat stress/fatalities
• 4: Development of high performance thermal protective clothing
• 5: Performance evaluation of thermal protective clothing
• 6: Modeling and its implications on performance of thermal protective clothing
• 7: Effects of various factors on performance of thermal protective clothing
• 8: Key issues related to thermal protective clothing
• References
• Index