A Brief Overview of Individual Protection in Chem/Bio Warfare



Background
The use of biological weapons as a means of waging war dates as far back as the sixth century B.C. when food poisons and contaminated corpses were used to infect opponents. Hannibal hurled venomous snakes into enemy ships in 190 B.C. During World War I (WWI), German troops conducted nearly 200 chemical attacks by releasing chlorine gas from thousands of cylinders. These attacks killed tens of thousands of troops and opened gaps in Allied lines as wide as five miles. Over the past twenty years, the threat of chemical/biological (CB) warfare has increased as some countries and terrorist networks continue to work on offensive applications and delivery systems of CB agents. There is intense concern about enhancement and proliferation of offensive programs in countries hostile to western democracies as well as potential terrorist use of weapons of mass destruction (WMD) to threaten military and civilian populations. Since U.S. Forces operate where the capability exists to employ CB agents, it is of paramount importance to protect the individual warfighter. Consequently, individual protective equipment and mitigation procedures are more important than ever.    Figure 1
Figure 1: Protective Mask - 1866. Cotton with elastic border to protect against aerosols

History of Individual Protective Equipment
The development of protective equipment for use against toxic CB agents parallels the development of CB weapons themselves. The earliest recorded gas mask proposal was written by Leonardo da Vinci in the 15th century. Da Vinci envisioned a fine cloth dipped in water for defense against a sulfide/arsenic toxic weapon he proposed. The conventional protective mask concept appeared in the mid-1800's. An early mask design is shown in Figure 1. Due to U.S. neutrality at the outset of WWI, few preparations were made for CB warfare. However, by the end of the war, the U.S. had standardized gas mask design and produced over 3 million masks for U.S. troops.

Figure 2: WWI Protective Suit - 1918 (click image for full view)

    In addition to mask designs, WWI saw the appearance of the first chemical protective suits. Figure 2 shows a WWI era, semi-permeable protective suit designed to provide protection against liquid and vaporous hydrogen sulfide. Unlike previous suits that were completely impermeable, this suit allowed the escape of perspiration from the body in the form of water vapor. The material consists of cotton sheeting coated with a solution of gelatin, glycerin, and zinc-sulphate and was treated with an excess of formaldehyde to make the gelatin water insoluble.

Fielded IPE Systems


The development of protective equipment for use against toxic CB agents parallels the development of CB weapons themselves. The earliest recorded gas mask proposal was written by Leonardo da Vinci in the 15th century. Da Vinci envisioned a fine cloth dipped in water for defense against a sulfide/arsenic toxic weapon he proposed. The conventional protective mask concept appeared in the mid-1800's. An early mask design is shown in Figure 1. Due to U.S. neutrality at the outset of WWI, few preparations were made for CB warfare. However, by the end of the war, the U.S. had standardized gas mask design and produced over 3 million masks for U.S. troops.

JSLIST Ensemble


The heart of today's military CB protective ensemble is the Joint Service Lightweight Integrated Suit Technology (JSLIST), shown in Figure 3. The JSLIST garments are worn with protective gloves, footwear, and a field protective mask to create a state-of-the-art CB protective ensemble that provides the best percutaneous and respiratory protection against CB warfare agents available to the warfighter today. The JSLIST ensemble is designed to protect the warfighter with minimal interference to the mission. The JSLIST is a two-piece, front-opening garment with an integral hood, bellows-type pockets, high-waist trousers, adjustable suspenders, adjustable waistband, and waist-length jacket. This protective garment is made of an outer shell that is a mix of nylon and cotton poplin rip-stop material with a durable water repellant finish. The inner-liner absorbs and contains the chemical agent; this layer consists of activated carbon laminated to a backing that is bonded to a tricot knit. The JSLIST garment (coat and trousers) weighs five to seven pounds depending on the size. Users include the Army, Navy, Air Force, Marine Corps, and specialized units outside DoD.

    Figure 3
Figure 3: JSLIST Protective Ensemble Shown in MOPP 4 (click image for full view)
The JSLIST garment can be worn for up to 45 days with six launderings and provides 24 hours of protection against battlefield concentrations of all known CB agents once contaminated. When compared to previous protective garments, the JSLIST provides reduced weight, increased durability, improved fit, enhanced suit closures, and a reduction in heat stress for the wearer. Each component (suit, boots, gloves, and mask) is based on state-of-the-art material technologies that have undergone extensive user evaluation as well as field and laboratory testing.

In 2006, the Joint Protective Aircrew Ensemble (JPACE) will be fielded to replace the existing CB protective suit for aviators and aircrew. JPACE is a one-piece, fire-resistant suit offering improved CB protection, reduced heat-stress, and allows an increased number of laundering cycles over existing suits. Like the JSLIST garment, JPACE is constructed with an inner layer of activated carbon in a urethane matrix that absorbs and contains chemical agents. When contaminated, JPACE provides 24 hours of CB protection after 30 days of wear.
Figure 4
Figure 4: M40 Protective Mask


   Masks

Field protective masks used with the JSLIST ensemble include the M40 series mask (Figure 4) and the MCU-2/P series mask (Figure 5). The M40 series mask consists of a silicone rubber face-piece and a replaceable face-mounted filter canister that can be mounted on either the left or right side. Paramount aspects of the M40 are user protection level and comfort. Field protective masks are designed to protect the user from battlefield concentrations of all known chemical warfare agents as well as biologicals and radioactive particulates. Key features include a wide field-of-vision, flexibility at extreme temperatures, weather and ozone resistance, ease of cleaning and maintenance, a voice amplifying device, and a drink tube. M-40 Mask variations include the ability to interface with armored vehicle communication systems.
The MCU-2/P mask is constructed of a one-piece urethane lens and a silicone rubber facepiece. The one-piece lens offers a large, unobstructed field of view. Dual canister mount accomodates both left- and right-handed wearers. The voicemitter system for the MCU-2/P provides the option for voice communication through a microphone hookup, located over the mask's mouth area. Army aviators use the M45 (general aviation) and the M48 (Apache helicopters), Navy and Marine Corps aviators use the AR-5 and the Air Force uses the Aircrew Eye and Respiratory Protection (AERP). The Joint Service General Purpose Mask (JSGPM) shown in figure 6 is to be fielded in 2006. The JSGPM is designed to replace the M40 and the MCU-2/P masks and will reduce weight, bulk and breathing resistance. In addition JSGPM will have a wider field of view and improved ability to interface with current and future protective clothing.

    Figure 5
Figure 5: MCU-2/P Protective Mask

Figure 6
Figure 6: JSGPM Protective Mask

    The Joint Service Aircrew Mask (JSAM) will also be fielded in 2006 and will replace six existing aircrew masks in DoD inventory. In addition to providing CB protection, JSAM will allow in-flight donning and doffing and will provide positive pressure breathing to protect against fatigue and loss-of-consciousness during rapid acceleration in high performance aircraft. Protective masks are a critical component of the warfighter's protective ensemble; comfort and ease of use can directly influence the warfighter's mission effectiveness.
Footwear

Although several types of protective footwear have been employed with chemical protective suits, the Multipurpose Protective Overboot (MULO) (Figure 7) is the current CB protective footwear solution employed by the Air Force and Marine Corps for the JSLIST ensemble. The Army and Marine Corps also use the green or black vinyl overboot (GVO/BVO). Both the MULO and the GVO/BVO are designed to provide up to 24 hour CB protection, upon exposure after 30 days of wear. The MULO is a single-piece design with webbed straps, side-to-back plastic buckle closures, and improved tread design. The MULO is designed for daily wear in the water, mud, and snow. The MULO's agent resistance is not degraded by exposure to petroleum, oils, lubricants (POLs) and decontaminants; hence, the MULO has the capability to be decontaminated to operationally safe levels after CB exposure. The MULO provides improved durability, enhanced compatibility, and comfort over the GVO/BVO.

   

Figure 7
Figure 7: MULO Boot
The MULO and the GVO/BVO are made of polymer blends that take a "set" when rolled or folded into a backpack. This renders the boot unfit for reissue. The Acton Lightweight Overboot (ALO) is a Commercial-off-the-Shelf (COTS) butyl blend that fulfills an urgent need by the U.S. Navy for a multi-size fit, reduced storage volume CB protective boot that does not take a set when rolled or folded. The ALO is an evolutionary approach to the Alternate Footwear Solution (AFS). AFS aims to minimize packaging volume, reduce weight, improve traction and reduce "set". Concurrent with the AFS program, work is underway to incorporate CB protection into a sock or boot liner, this is the Integrated Footwear Solution (IFS). The ultimate aim of AFS and IFS is to integrate CB protection into current military footwear without compromising durability or comfort for the warfighter.
Gloves

The chemical protective glove consists of an outer glove for chemical protection and an inner glove for perspiration absorption (Figure 8). The outer glove is made of impermeable butyl rubber and the inner glove is made of white cotton. The gloves come in three thicknesses: 7, 14, and 25 mil. The 7-mil glove is used by medical personnel, teletypists, electronic repair personnel, and others who require tactility and touch sensitivity and will not expose the glove to harsh treatment. The 14-mil glove is used by aviators, vehicle mechanics, weapons crews, and personnel whose tasks require some touch sensitivity. Personnel who perform close combat and other heavy labor use the 25-mil glove. Butyl gloves protect against liquid chemical agents and vapor hazards and can be decontaminated and reused; however, gloves will become sticky and soft if exposed to some decontaminants or petroleum-based fluids and must then be replaced.
Figure 8
Figure 8: 14-mil CB Protective Glove

   The Joint Block 1 Glove Upgrade (JB1GU) fulfilled an urgent USSOCOM requirement for a glove with increased tactility and dexterity. JB1GU provides protection from liquid, vapor and aerosol CB hazards equal to or better than the current glove. The JB1GU offers 24 hours of protection in a contaminated environment and is durable up to 14 days. JB1GU also achieves most requirements in JSLIST ORD and serves as an evolutionary approach to the second block glove upgrade (JB2GU). JB2GU will add flame resistance, 30 day protection/durability, and will replace all butyl rubber gloves (7, 14 and 25 mil).
Operational Wear

The chemical protective ensemble items are donned based on Mission-Oriented Protective Posture (MOPP) levels designated by the commander. MOPP is a doctrinal procedure that allows protection levels to increase or decrease depending on the existing mission-specific threat. When the threat level demands complete percutaneous and respiratory protection, MOPP 4 provides total encapsulation. In MOPP 4 (shown in Figure 3) the JSLIST garment is worn so that the trouser legs are fastened over the tops of the protective boots, the sleeve cuffs are fastened over the gloves, and the hood is tied securely around the edge of the mask. This CB protective ensemble completely encloses the wearer and provides head-to-toe skin, respiratory, and ocular protection.
Developmental Projects

To optimize mission-effectiveness, it is important that IPE design consider not only protection but also comfort. Placing a warfighter in MOPP 4 adds up to 14 pounds to the warfighter's existing load. Consequently, MOPP levels must be balanced against workload for troops to remain effective. The commander must consider the potential for mission impairment caused by added weight, heat stress, dehydration, and physical exertion in wearing the full ensemble. This additional burden (for both warfighter and command) highlights the potential for IPE improvement. Clearly, cooling technologies are needed to improve wearer comfort and enhance mission success. Novel materials and innovative design concepts must be exploited to provide improvements in performance and wear-ability. Specific product capability enhancements sought include:

  • Cooling technology (systemic or material)
  • Novel adsorbents (e.g. nanoparticle technology, TIC removal)
  • Self-decontaminating fabrics and polymers (e.g. reactive materials)
  • Novel closure concepts
  • Novel integration concepts
  • Alternate source qualifications
  • Improved filtration technologies

Expanded comfort and protection capability is sought for existing masks and mask filters to include toxic industrial chemical (TIC) removal. Lighter, less bulky, self decontaminating masks that are fully integrated into other IPE are envisioned. In addition, less-bulky filters and extended filter life are desired to enhance wear-ability and user comfort. Another desired comfort enhancement is a filter having reduced breathing resistance that will reduce the amount of work required to breathe.

The next generation CB glove will have improved durability, tactility, dexterity, POL resistance, comfort, and will be able to be used in all applications (e.g. ground, shipboard or aviation). Next generation footwear will provide extended protection and wear times with improved traction and will be able to be donned and doffed while wearing gloves, mask, and suit. Continued emphasis will be placed on integrating CB protection (footwear, hand-wear, and clothing) into the standard duty uniform.