Dressed for Defense

Dressed for Defense

Byline: Jeffrey O. Stull, President International Personnel Protection Inc. Austin, Texas

While first responders accept that they will face potential disasters and an array of hazards including fire, difficult rescues, chemical accidents and exposure to bloodborne pathogens, the possibility of large-scale, intentional and toxic events gives most first responders pause.

How to protect first responders in these situations is a major concern that has no clear answers, but it does warrant rethinking the whole strategy of personal protective clothing and equipment when dealing with weapons of mass destruction.


The effects of military-type weapons of mass destruction were seen in March 1995 when terrorists released sarin gas in the Tokyo subway system, killing 11 and injuring more than 5,500 people. However, weapons are not limited to military-type agents. They can be toxic industrial chemicals, harmful microrganisms or radiological materials delivered in a destructive fashion.


While much of the focus has been on chemical warfare agents including sarin, distilled mustard gas and VX nerve agent, higher threat potential exists with the more easily accessible toxic industrial chemicals such as ammonia, chlorine, dimethyl sulfate, hydrogen cyanide and phosgene.

Chemicals generally are dispersed as a fine aerosol, which allows them to remain airborne as long as possible, to disseminate over a wide range and to contaminate extensive surface areas once the small liquid droplets fall to the ground. However, some chemical substances like chlorine and ammonia can be released as gases while others can be used in their liquid form to create pools or contaminate surfaces.

The concern over chemical agents used in terrorism relative to protective clothing is the ability of the chemical to permeate materials and penetrate through clothing openings.


More often than not, the dissemination of a biological agent such as anthrax, smallpox or plague will not be as obvious as the post-Sept. 11 anthrax incidents, will not have a recognized point of origin and will not be recognized as a biological agent until the first widespread symptoms appear. Biological agents may be disseminated by a variety of means, including releasing an airborne pathogen into populated areas, injecting liquidborne pathogens into food or water supplies, and even using terrorists themselves as the carrier of deadly diseases.

Biological agents must penetrate protective clothing’s material or pass through the clothing’s design; unlike chemicals, biological agents don’t permeate materials. Also, the route of entry for many biological agents is through inhalation, though the skin should also be protected to prevent secondary exposures and the spread of contamination.


Certainly there are many hazards associated with the detonation of a nuclear device, but the post-release radioactivity can create long-term radiation problems that decay over time based on the half-life of radioactive isotopes, which range from minutes to hundreds of years. Some higher-energy isotopes more easily pass through solid materials. The practices used to protect against radiological hazards include time, distance and shielding. Under emergency conditions, it’s difficult to apply these practices.

In reality, there is very little “N” in the traditional “NBC” protective clothing. Until recently there have been no effective forms of protection against all forms of ionizing radiation. While simple barriers and most types of clothing will generally stop alpha and beta particles, these are ineffective against the energy associated with gamma rays or X-rays.

Current industry issues

A substantial amount of effort has gone into equipping first responders with protection against weapons of mass destruction. Many grant programs are providing monies that aren’t ordinarily available to already strapped municipal fire departments and other emergency responders.

This national mobilization has brought positive developments, but several negative aspects also have characterized it:

*New research shows the limitations of conventional and existing protective clothing, but some of this information has been misunderstood and misused.

*There has been a flood of products into the market for WMD protection, but many of these are not properly designed, tested or represented.

*Over $1 billion in grant funds are available to qualified departments, but spending on appropriate clothing and equipment hasn’t been standardized.

The average firefighter isn’t likely to have special clothing on-hand to protect against WMD, instead responding to emergencies in turnout gear. So the obvious question becomes how much protection does turnout clothing provide against weapons of mass destruction?

The U.S. Army Soldier Biological and Chemical Command provides basic information on protection levels for one type of structural firefighting turnout, based on a single set of materials, evaluated in pristine condition against only sarin and distilled mustard. Their findings are commonly called the “3/30 rule,” which states that standard turnout clothing and SCBA will provide a first responder with sufficient protection from nerve agent vapor hazards inside interior or downwind areas of the hot zone to allow 30 minutes of rescue time for known, live victims. Self-taped turnout clothing with SCBA provides sufficient protection in an unknown nerve agent environment for three-minute reconnaissance to search for living victims, or two minutes in suspected mustard gas releases.

Unfortunately, in the absence of other resources many departments have interpreted this information to mean that turnout clothing offers limited protection for WMD events, foregoing any broader strategy for equipping their firefighters with other forms of protective clothing that will provide the appropriate protection against a much wider range of hazards than just chemical agents.

However, there are a great number of variables not considered in this analysis, including:

*The types of materials used in the construction of firefighter protective clothing;

*The condition of turnout clothing, especially clothing that has been washed several times;

*The effectiveness of self-taping; and

*The manner in which the firefighter is exposed.

SBCCOM likewise provides extensive evaluations of selected chemical protective clothing using both material testing with actual chemical agents and overall garment integrity testing against simulated agents. Although not all-inclusive, the National Institute of Justice, through the efforts of the National Institute for Standards and Technology’s Office of Law Enforcement, has prepared the Guide for the Selection of Personal Protective Equipment for Emergency First Responders, which includes both selection information and a compilation of personal protective equipment. The publication is available at www.ojp.usdoj.gov/terrorism/whats_new.htm.

Available PPE, standards

There are products in the marketplace similar to the protective clothing commonly used by hazmat teams. Unfortunately the protective clothing system used for the hazmat team doesn’t fully protect against weapons of mass destruction. It also isn’t available for first responders as a group; it’s simply not practical to provide every first responder a totally encapsulating chemical protective suit, even though encapsulating suits are the only appropriate protection for some WMD responses.

The traditional two-level system, Levels A and B, failed to capture the scope of response hazards, particularly when a broader base of users needed to be considered. NFPA 1994, Protective Ensembles for Chemical/Biological Terrorism Incidents (2001), covers a range of terrorism hazards beyond chemical agents. This standard sets performance requirements and defines three classes of ensembles based on the perceived threat at the emergency scene. Differences between the three classes are based on:

*The ability of the design to resist the inward leakage of chemical and biological contaminants.

*The resistance of the materials to chemical warfare agents and toxic industrial chemicals.

*The strength and durability of these materials.

All NFPA 1994 ensembles are designed for a single exposure. Ensembles must consist of garments, gloves and footwear.

Class 1 ensembles

Class 1 ensembles offer the highest level of protection. The suits are required to:

*Provide integrity to gases by passing an inflation test with the exhaust valves plugged.

*Show less than 0.02% penetration of surrogate gas during an inward leakage test involving a human test subject who is physically exercising while wearing the ensemble.

*Use materials that provide the highest level of permeation resistance against chemical warfare agents, toxic industrial chemical liquids and gases.

*Use materials that possess relatively high levels of resistance to abrasion, tearing, punctures and cuts.

Class 1 ensembles are intended for the worst-case scenarios, where the substance involved creates an immediate threat, is unidentified and is of unknown concentration. Such situations would occur where there’s an ongoing release with likely gas/vapor exposure, the responder is close to the point of release, and most victims in the area appear to be unconscious or dead from exposure. Stay times in the hazard zone are likely to be short and limited to the breathing air available from the SCBA.

Class 2 ensembles

Class 2 ensembles offer an intermediate level of protection. These ensembles must:

*Show no more than 2% leakage of the outside environment into the ensemble as demonstrated by the same gas test described for Class 1.

*Pass a shower test that shows that the suit will not allow any penetration of liquid when sprayed from several directions.

*Demonstrate permeation resistance to chemical warfare agents and liquid/gaseous toxic industrial chemicals. However lower concentrations of these chemicals are used in testing as compared to Class 1. (For example, gases are tested at a concentration of 0.1% in air.)

*Be rugged but at lower physical property levels than Class 1 ensembles.

Class 2 ensembles are intended for circumstances where the agent or threat may be identified, when the actual release has subsided, or in an area where live victims may be rescued. Conditions of exposure include possible contact with residual vapor or gas and highly contaminated surfaces at the emergency scene. Most victims in the response area are alive and show signs of movement, but are non-ambulatory. For Class 2 ensembles, breathing air from the SCBA may still limit wearing time. However, Class 2 ensembles may also be configured with powered air-purifying respirators that provide longer duration response time.

Class 3 ensembles

Class 3 ensembles offer the lowest level of protection. Unlike Class 1 and 2, these ensembles aren’t required to show any resistance to leakage of vapor or gas from the outside environment. However, the suits must be resistant to inward liquid penetration as demonstrated by passing a short-duration shower test. These ensembles are not tested against gases, but they still must provide permeation resistance to low concentrations of liquid chemical warfare agents and liquid toxic industrial chemicals where the liquid is permitted to evaporate during the test.

Class 3 ensembles are intended for use long after the agent release, at relative large distances from the point of release, or in the peripheral zone of the release scene for such functions as decontamination; patient care; crowd, perimeter and traffic control; and clean-up. These ensembles should only be used when there is very little potential for vapor or gas exposure, where exposure to liquids is expected to be incidental through contact with contaminated surfaces, and when dealing with patients or self-evacuating victims.

Ensembles must cover the individual, and it’s preferred that this clothing also cover the wearer’s respirator to limit potential for contamination. Because these ensembles are intended for longer wearing periods, the use of air-purifying respirators with these suits is likely.

Surprisingly, industry response to NFPA 1994 has been slow. The testing required by the standard is both rigorous and expensive. Manufacturers also may have been reluctant because purchasers are not aware of the standard and specific demand for certified products hasn’t been forthcoming.

Nevertheless, given the monies available for the purchase of clothing and equipment and the drive for standardization of products, it seems irresponsible for manufacturers to offer clothing with claims of protection against WMD without the appropriate testing and certification as required by the consensus-based NFPA 1994 standard.

The NFPA 1994 technical committee is conducting an early revision of the standard to address an even wider range of WMD hazards and clothing performance issues. As with the development of any NFPA standard, the process is open for public proposals and comments. For more information, contact NFPA Staff Liaison Bruce Teele at 617-770-3000.

Efforts for industry coordination

WMD events need a great deal of coordination and cooperation from a large number of organizations. It’s also critically important that response efforts mesh in all areas, including personal protective equipment.

Helping to meet this need is the Interagency Board for Equipment Standardization and Interoperability, a working group supported by voluntary participation from various local, state and federal government and private organizations. Its mission is to establish and coordinate local, state and federal standardization, interoperability and responder safety requirements to prepare for, respond to, mitigate and recover from any incident by identifying requirements for chemical, biological, radiological, nuclear or explosives incident response equipment.

Key functions of the IAB include:

*Facilitating integration among local, state and federal response communities to promote proper selection and use of the best available equipment and procedures to optimize safety, interoperability and efficiency.

*Developing, maintaining and updating the Standardized Equipment List, which provides the responder a reference to the type of equipment required to prepare for, respond to, mitigate and recover from a CBRN incident.

*Advocating for, assisting in, and promoting the development and implementation of performance criteria, standards and test protocols for SEL-listed CBRN incident response equipment.

*Encouraging the coordination of local and state response communities with established military and federal acquisition programs for procurement of SEL-listed CBRN incident response equipment.

The SEL names essential equipment items needed by local, state and federal organizations for domestic preparedness. In addition to identifying the types of the items to be used, the list establishes the minimum requirements for many of those items by setting requirements for conformance to specific standards.

Many grant programs require or will shortly require use of the SEL as the source of information for submitting grant applications. Consequently, organizations must make their requests for response equipment based on items that meet the requirements of the SEL, such as NFPA 1994 compliance.

This SEL is divided into the four areas representing the organization of the IAB. For the 2002 edition of the SEL, available later in this year at www.iab.gov/sel, all listed PPE items are linked with existing standards. This means that clothing and equipment items must meet the appropriate standard to meet the SEL requirements. In turn, only equipment that meets SEL requirements can be submitted as part of many grant applications.

It’s important to recognize that some protective ensembles provide limited protection in WMD events. For example, structural firefighting protective clothing in its current configuration for meeting NFPA 1971 requirements provides no CBRN protection but may be useful in parts of the response. Similar caveats exist for ensembles and clothing compliant to NFPA 1951, Protective Ensemble for USAR Operations; and NFPA 1999, Protective Clothing for Emergency Medical Operations.

In future editions of the SEL, the IAB intends to list clothing and equipment that demonstrably comply with the SEL requirements. NIOSH has also recently completed new criteria for CBRN approval of air-purifying respirators and is working on related criteria for escape hood and powered air purifying respirators.

The world is seemingly a more dangerous place for the first responder. While there are an incredible amount of products and information to sift through and consider, there are large uncertainties and many problems to overcome. Much of the new funding from grants is being wasted on protective clothing that provides inadequate performance and in some cases may give a false sense of security. Some information is not properly understood or applied to protective clothing and equipment selection.

Nevertheless, due in part to the efforts of several organizations such as SBCCOM, the National Institute of Justice, NFPA, NIOSH, IAB, firefighter unions and others, the protective clothing industry is moving in a direction to offer better guidance and, more importantly, effective levels of minimum protection as defined by standards and appropriate protocols for use.

Jeffrey O. Stull is president of International Personnel Protection Inc., an Austin, Texas, – based company that provides expertise on the design, evaluation, selection and use of protective clothing and equipment. Stull formerly headed the U.S. Coast Guard’s Hazardous Chemical Personnel Protection Project, where he developed and evaluated several new protective clothing and equipment systems for the National Strike Force. He’s a member of the American Society for Testing and Materials and the NFPA Technical Correlating Committee on Fire and Emergency Medical Services Protective Clothing and Equipment. Stull has a bachelor’s degree from the U.S. Coast Guard Academy and master’s degrees in chemical engineering from the Georgia Institute of Technology and engineering management from the Catholic University of America.

Permeation versus penetration

Permeation is the process by which chemical substances move through materials on a molecular scale. The chemical contacts the exterior of the protective clothing material as a gas, liquid, or aerosol and diffuses through the solid material to be released as a vapor on the interior side. Permeation can occur through the material, seams or other components of the clothing. In contrast, penetration is the bulk flow of a gas, vapor, aerosol or liquid through a porous material (such as the outer shell of turnout clothing), defects in a material, unsealed seams, non-tight closures or interface areas where gloves, boots, or respiratory equipment join the clothing. Penetration of chemicals is most often related to the clothing design. Clothing can be “gas-tight” for preventing the penetration of chemicals by all forms, or “liquid-tight” for primarily preventing the penetration of liquid splashes.

New radiological protection available

Lead and other heavy, dense metal shielding have been considered the only means to protect against gamma or X-rays. Many of the articles used in the medical profession to protect against the health uses of ionizing radiation consist of lead panels embedded in vests and related clothing articles. These materials do not readily lend themselves to use in protective clothing. However, new material technology has been developed that offers the potential for full body clothing capable of attenuating the energy associated with several, but not all, forms of ionizing radiation, including low- to moderate-energy gamma rays. The new technology offered under the trade name Demron is provided by Radiation Shield Technology (www.radshield.com) and provides protection equivalent to lead at the same thickness. However, it is important to point out that radiological protection is still limited on the principle of time, distance and shielding. This means that clothing only lessens the amount of energy passing through to the body and that the time on scene must still be controlled to limit the dose of radiation to acceptable levels. Further, the energy of the radioactive source lessens the greater the distance from the source.

Army takes lead in WMD protection research

The U.S. Army Soldier Biological and Chemical Command is one of the premier organizations helping in the research and development of personal protective equipment for first responders involved in WMD events. The National Protection Center of SBCCOM is a Joint Agency Center of Expertise. The NPC sponsors and executes research, development, testing and evaluation, and promotes commercialization of advanced/multi-threat protective clothing and equipment for military and civilians in high-risk occupations or on missions in extreme environments. Its founding members, NASA and the National Institute of Justice, create partnerships with other federal and state agencies, users, industry and academia to identify, consolidate and leverage requirements, projects, capabilities and resources. SBCCOM has been heavily involved in the testing and development of protective clothing for first responders against WMD. A variety of test reports and information are provided on their Web site at www.natick.army.mil/soldier/NPC.

Industry releases first NFPA 1994 – compliant product

DuPont has recently completed the certification of a multi-piece CPF 3 coverall to the Class 3 requirements of NFPA 1994. This ensemble consists of a hooded coverall with elasticized face opening, front closure with inner and outer storm flaps, bootie feet with overboot splash cover, attached Ansell Barrier and Best Manufacturing Black Knight gloves, and two different hood options. The respirator-fit hood is a short hood with a visor that accommodates the wearing of and exhalation of air from an air-purifying respirator, while a longer hood is provided to cover more of the wearer’s upper torso and to protect the SCBA air tank.

Comparison of classes

Respiratory protection for WMD

NIOSH has established additional criteria for certifying self-contained breathing apparatus against chemical, biological, radiological and nuclear threats. These criteria include both component and whole SCBA testing against chemical agents, in addition to the SCBA being already NIOSH-certified as an industrial SCBA and meeting the fire service requirements of NFPA 1981, Open-Circuit Self-Contained Breathing Apparatus for Fire and Emergency Services. Since releasing the criteria last year, two manufacturers, Interspiro and Scott Health & Safety, have been able to certify specific SCBA against the new criteria.

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