Medical Aspects of Chemical Warfare (2008) - The Black Vault

Chemical Defense Equipmentabjoint service lightweight integrated suit technology(JSLIST) type VII users to protect the head and neckfrom exposure to agents, because these suits lack ahood. An audio frequency amplifier and microphoneassembly (microphone and microphone adapter) areprovided for amplified voice communication. Eachfacepiece assembly has serial number bar code as wellas human-readable lot and serial numbers located onthe filter mount assembly. 14,15Protective ClothingAn overgarment can be made to protect skin fromchemical agents by either physical or chemical means,depending on the type of fabric:• the fabric may be impermeable to most molecules,even to air and water vapor, or• the fabric may be permeable to most moleculesbut chemically alters or physically removeschemical agents before they reach the skin.An overgarment made of the first type of fabric,which can be butyl rubber or an impermeable plastic,offers complete protection against threat agents butplaces a significant heat load on the wearer and limitsmovement. Because the individual’s skin does notcontact the outside air, sweating does not cool the bodyand heat is retained. Most fielded military garmentsFig. 17-11. (a) The M53 chemical-biological protective mask ispositive-pressure capable and provides an internal variableresistance exhalation unit for operations with self-contained,closed-circuit and powered-air breathing systems. (b) Illustrationof the M53 mask front facepiece assembly.Photograph (a): Courtesy of the Chemical Casualty CareDivision, US Army Medical Research Institute of ChemicalDefense, Aberdeen Proving Ground, Md. Drawing (b): Courtesyof the Respirator Engineering and Acquisition Team,ECBC-RDECOM, Aberdeen Proving Ground, Md.utilize the second type of fabric technology, whichallows some limited air exchange through the fabricbut filters the air through a charcoal lining, which alsoabsorbs agent.The decision to place a service member into fullchemical protective equipment—mask, overgarment,gloves, and boots—must take into account not onlythe provided protection but also the added heat stressand potential for dehydration. 1 To guard against dehydration,personnel must begin a drinking regimenbefore encapsulation. The physical burden of a fullensemble can add 5 to 7 lbs to a normal load; this addedweight combined with heat stress, dehydration, andphysical exertion can cause significant impairmentto any mission. Because of these factors, the militarydeveloped MOPP levels to stratify the levels of requiredprotection based on the anticipated threat risk(Figure 17-12). There are seven MOPP levels; Exhibit17-1 describes each level in detail. More informationon the applications of the various MOPP levels can befound in Field Manual 3-11.4, Multiservice Tactics, andProcedures for NBC Protection. 14 The MOPP level mustbe coordinated with the workload if personnel areto remain effective. Overgarments are continuouslyredesigned to reduce heat stress, reduce weight andbulk, and provide increased comfort as well as reducethe logistical burden.569