Today’s first-responder community is continually searching for the most effective technology to provide protection during a hazardous materials or WMD (weapons of mass destruction) incident. However, because most incidents to which first responders are dispatched do in fact involve hazardous materials, it is imperative that the responders are wearing or have with them the personal protective equipment (PPE) appropriate both to the hazard and to the response objectives. U.S. and allied manufacturers are for that reason trying to meet the triple challenge of not only keeping up with the technology available and the PPE standards established – by both the U.S. government and several non-government organizations such as ANSI (the American National Standards Institute) and NFPA (the National Firefighters Protective Association) – but also adhering to the cost limitations that the responders are asking for.
Since the early 1980s, numerous standards and regulations for chemical protective ensembles have been developed to assist both the responders and those who work with hazmat materials on a daily basis. The push for better – i.e., safer, more comfortable, and reasonably priced – PPE gear has been driven, at least in part, by incidents such as the tank car leak of anhydrous dimethylamine in Benicia, California, that helped persuade the standards organizations and regulatory agencies to establish more stringent minimum-performance standards for chemical protective clothing ensembles.
In recent years, several new standards and regulations, more comprehensive than their predecessors, have been published and kept updated to meet the needs of the responder community. Among the more important of them are NFPA 1991 Standard on Vapor-Protective Ensembles for Hazardous Materials Emergencies, the NFPA 1992 Standard on Liquid Splash-Protective Ensembles and Clothing for Hazardous Materials Emergencies, and the NFPA 1994 Standard on Protective Ensembles for First Responders to CBRN [chemical, biological, radiological, nuclear] Terrorism Incidents. These and several others have become extremely useful tools for responders choosing the PPE needed for their personal safety.
Leveling the Ensemble Playing Field
One of the more important definitions found in the NFPA standards, which are written specifically to help responders choose the appropriate protective equipment, is the term “ensemble.” The responder has to look at the individual chemical protective equipment items that he (or she) chooses as separate components of the ensemble as a whole. The suit, boots, gloves, respiratory equipment, and various accessories make up the ensemble, and each of those individual equipment items must be thoroughly researched prior to being purchased and used on a response.
Unfortunately, there is what might be called a “language problem” that has caused a lack of understanding, and sometimes outright confusion, within the response community when it comes to choosing the whole ensemble. The official standards and other documentation used to describe PPE items usually refer to the equipment as ensembles, but many members of the response community use shorter and more easily remembered names for the same equipment – “Level A,” “Level B,” or “Level C” suits, for example, rather than the “official” ensemble names. The official names come from EPA/OSHA (Environmental Protection Agency/Occupational Health and Safety Administration) guidelines and are both longer and more difficult to remember.
The separate equipment items making up the ensemble need to be researched individually when a response mission is tasked. However, the same changes in technology that have made PPE gear more effective have at the same time made the choice of ensembles a greater challenge than in the past. For example, the newer versions of NFPA 1991 require that all materials used in construction of the suit – base material, seams, and closures – must demonstrate resistance against various chemicals (the boots and gloves must meet that same requirement). Some manufacturers were unhappy about the more stringent procedures required under the new testing standards, but the end result was that this added challenge caused the manufacturers to reevaluate their current products and develop new materials more suitable to the responder community’s needs.
Following are some of the factors involved in selection of the specific equipment items indicated:
Gloves – Most responders today use two or more layers of gloves to protect themselves against the hazards of an incident. From the innermost gloves – made of Nitrile materials to provide the last layer of protection against chemical/biological exposure – to the outermost glove, which is made from leather to protect the wearer’s hands and fingers from mechanical damage, hand protection is always, and necessarily, a high-priority equipment item because well-designed gloves facilitate the manipulative skills needed to mitigate hazmat effects and/or sample potentially hazardous materials during a hazmat response.
The number of pairs of gloves that should be worn by the individual responder is based on the need for protection against several hazards. Among the questions that should be asked before selecting gloves are the following: What are the general hazards of the product? Are there mechanical hazards likely? What are the dexterity needs?
Boots – Responders who are working at hazardous materials/WMD incidents, including leather fire/work boots, rubber boots, etc., must meet the specifications of ANSI Z41 1991. The materials used to make the boots are not usually subject to any specific standard; however, the construction of the boot is. Depending on the type of hazard and the specific product, for example, the boot should protect the wearer against both liquids and solids. That requirement which translates into a boot made of neoprene, polyvinyl chloride (PVC), butyl rubber, or any of several other materials that are available today.
Most if not all of the boots now used by responders come in different configurations to suit the needs of the individual user. They are available either as a shoe boot or as a “pullover” boot. Pullovers are less expensive and usually considered to be disposable. When wearing chemical-resistant shoe-boots, the responder should first slip his or her feet into the boots to ensure a comfortable fit; a protective rain flap will then go outside and over the boots to prevent liquids from entering.
Choosing respiratory protection is not a complicated matter. Once a specific hazard has been determined and the level of protection (OSHA/EPA or NFPA) needed has been decided, the type of respiratory protection required is almost automatic. However, responders can choose a suitable respirator only after they have evaluated all of several relevant factors involved, specifically including the limitations of each type of respiratory protection equipment available. The first priority should be identification and evaluation of the respiratory hazard. After those tasks have been done, there are several important questions that should be asked, including the following:
- Is the specific equipment item to be used in firefighting and/or hazardous material/WMD emergencies?
- Has the atmosphere been monitored for oxygen, flammability, and contaminant levels? Here there are several supplementary questions required: (a) Is the atmosphere oxygen-deficient (less than 19.5 percent oxygen in air)? (b) Is the airborne contaminant a gas, a vapor, or a particulate (mist, dust, or fume)? (c) Are the airborne levels below or above the exposure limit – and/or are they above levels that could be immediately dangerous to life or health?
- What are the operational conditions – e.g., cold/hot temperatures, confined space, etc. – most likely to be encountered?
- What is the specific mission of the individual responder (e.g., rescue, recon, retrieval, etc.)?
- How long will the mission last – i.e., how long will the responder have to wear the respiratory equipment?
Although not a complicated process, the selection of respiratory equipment does require the preceding and possibly a few other questions to be answered. In today’s environment, fortunately, the technology already developed and available for purchase alleviates some of the selection problems. A good example is that the face-piece used with today’s self-contained breathing apparatus (SCBA) can be adapted for use as an air-purifying respirator or a powered air-purifying respirator.
Chemical Protective Clothing
The purpose of chemical protective clothing is to protect the wearer against hazardous liquids, gases, or vapors. Most of the clothing now available comes in a large array of styles and materials. The choice of what to wear is or should be based on the information available to the responder upon his/her arrival at an incident. Depending on the specific hazard(s) encountered, the responder can choose minimal protection or any of several intermediate levels of clothing up to the highest level. Many of the materials now available allow the responder to make choices based on the suitability of the specific material to the specific hazard encountered. The protective clothing may be made of Tyvek or Coated Tyvek, for example, both of which are durable, or of Nomex, which also is fairly durable and provides better flammability protection. All of these materials are usually categorized as “limited-use” – disposable, in other words.
As the hazards to the body progress in size and/or complexity, so does the level of protection needed. The materials that are used – e.g., polyvinyl chloride – become more complex, and therefore may be more suitable for liquids, which are stronger corrosive materials. This will provide for minimal contact with the materials. From a cost perspective, some may be inexpensive enough to be disposable.
As a hazardous material presents an even a higher level of toxicity, additional protection is necessary. Materials such as the neoprene and butyl rubber mentioned earlier are good barriers against toxic hazards. Both of these materials are designed to provide a higher level of protection because of their ability to stop toxic hazards from entering the material worn by the responder. Once an incident reaches the highest level of toxic vapor/gases, though, the requirement for the most complete protection available becomes mandatory. Today, the highest level of protection is the fully encapsulating suit. These suits are designed to totally block any permeation, penetration, or degradation by the chemical hazards to which the suit (and the wearer, of course) is exposed. All closures, including zippers and seams, also are specially designed and fitted to resist the chemical vapors/gases that the wearer will encounter.
Circulation, Perspiration, and the End of a Tradition
There are many problems encountered by the wearer of protective clothing, the primary one being that his or her body is shielded not only from dangerous chemicals but also from the normal circulation of air. Moreover, his/her perspiration does not evaporate, thus eliminating the body’s own principal mechanism for cooling. The addition to the protective suit of one of the several new technology-driven cooling systems is therefore necessary to help the wearer’s own hypothalamus (the body’s thermostat) reduce his/her body temperature immediately in a heat-stress situation. Heat-related problems are very common when the ambient temperature climbs above 75 degrees F.
To briefly summarize: The selection of appropriate personal protective equipment is based on several key factors, including the mission of the response team and the hazards anticipated or immediately recognized. Protective clothing protects the wearer primarily because of the materials from which the clothing is made. Today’s hazardous materials/WMD responder has many choices in personal protective equipment available. Those choices should be made primarily on the basis of providing greater safety to the responder.
The practice known as “risk-based response” has evolved to the point that the best protection available can and should be made on the basis of hazard assessments completed by responders on the scene in the early stages of an incident. The old, heroic, and time-honored procedure of first responders arriving on the scene of a dangerous incident and immediately rushing into action is a relic of the past and has no place in the 21st-century world of terrorist attacks, mass-casualty incidents, and warehouses stacked from floor to ceiling with a host of lethal chemicals and other toxic materials.
Glen Rudner retired in 2022 as a manager of environmental operations for the Norfolk Southern (NS) Railway with environmental compliance and operations responsibilities in Tennessee, Alabama, Mississippi, and Louisiana. Previously, he was the hazardous materials compliance officer for NS’s Alabama Division (covering Alabama, Mississippi, Louisiana, and southwestern Tennessee). Prior to NS, he served as one of the general managers at the Security and Emergency Response Training Center in Pueblo, Colorado. He worked as a private consultant and retired as a hazardous materials response officer for the Virginia Department of Emergency Management. He has nearly 42 years of experience in public safety. He spent 12 years as a career firefighter/hazardous materials specialist for the City of Alexandria Fire Department, as well as a former volunteer firefighter, emergency medical technician, and officer. As a subcontractor, he served as a consultant and assisted in developing training programs for local, state, and federal agencies. He serves as secretary for the National Fire Protection Association Technical Committee on Hazardous Materials Response. He is a member of the International Association of Fire Chiefs Hazardous Materials Committee, a member of the American Society of Testing and Materials, and a former co-chairman of the Ethanol Emergency Response Coalition. He served as a member of the FEMA NAC RESPONSE Subcommittee.