MISSION ORIENTED PROTECTIVE POSTURE

Mission oriented protective posture (MOPP) procedures are used to establish levels of readiness for a chemical agent attack. The procedures are flexible. They allow the commanding officer to adapt the requirements for protective clothing and equipment to the degree of threat and working conditions at any given time. As an example, personnel doing heavy work in hot weather may

suffer heat exhaustion in the heavy protective clothing and gas masks. Therefore, unless an attack is actually underway, it may be best to relax the protective clothing requirements to prevent certain injury or sickness from heat. Other cases

are personnel who cannot do their work wearing protective gear, those who need to eat or attend to body functions, and other requirements not possible in protective clothing. For detailed information on MOPP, see chapter 470 of the

Naval Ships' Technical Manual.

PROTECTIVE EQUIPMENT

All naval personnel, particularly Damage Controlmen, should be familiar with the protective equipment designed for CBR defense. The following paragraphs cover protective masks and clothing.

PROTECTIVE MASKS

The protective mask is your single most important piece of protection against CBR attack. You inhale about 10 liters of air each minute and even more when you exercise. You can see that you can inhale a lot of CBR contamination very

Figure 10-1.-Nomenclature of ND Mk V protective mask.

quickly. The protective mask filters those contaminants out of the air you breath.

The protective mask now in use in the Navy is the ND Mk V (fig. 10-1). It is made up of two main parts: the facepiece and the canister system. The mask is kept in a carrier until it is needed (fig. 10-2).

The facepiece should fit snugly over your face to form a perfect gastight seal. This seal protects your eyes, face, and lungs. Use the harness assembly to strap the mask to your head and secure it firmly. The mask has eyepieces and a speaking diaphragm for voice communication. A one-way valve allows you to exhale to the atmosphere, but not to inhale from the atmosphere. A connection assembly allows you to inhale from the canister.

The canister consists of a metal body containing a mechanical and chemical filter system. The mechanical filter is a fine screening material that collects particles-biological and chemical agents, radioactive dust, and smoke particles. The chemical filter absorbs vapors that pass over the porous surface of activated charcoal and are caught in the small holes and condensed. The mask protects against most chemical agents in normal concentrations. Certain gases, such as carbon monoxide, carbon dioxide, ammonia, and commercial fuel gases will pass through the canister. You will need special masks to protect against these gases. Information on these masks can be found under the subject headings in various chapters of the

Naval Ships' Technical Manual.

The canister cannot supply or manufacture oxygen; it offers no protection from an oxygendeficient atmosphere.

Figure 10-2.-The ND Mk V protective mask and carrier. 10-6

Minimize exposure of the canisters to spray or rain. Replace canisters that have been soaked with water.

Each canister comes with seals over the intakes and outlets to keep out moisture. Remove and discard these seals when you put the canister into use. Do not try to replace the seals if the canister is used or left open more than a few minutes.

The Mk V mask has also been designated as an interim emergency breathing device for escape from smoke-filled areas where the oxygen content is above 18 percent. The mask should not be used as a working unit in fire fighting or as rescue apparatus.

NOTE: A new protection mask, the MCU2/P, is now being tested for possible use as a replacement for the Mk V mask.

Care of the Mask

Be certain the Mk V mask is in good condition; it maybe needed to save your life. Keep the mask dry. Moisture causes rotting of parts, corrosion of the metal, deterioration of the canisters, and mildewing of the carrier. Perspiration should be removed carefully.

Place only authorized equipment in the carrier.

Handle the masks carefully. Rough treatment may cause serious mechanical damage to the metal parts, tears in delicate portions, and scratched or broken lenses.

Inspect the masks regularly and make repairs promptly.

Place the mask properly in the carrier.

Store the mask in a cool, dry, dark place. If it is necessary to stow the mask unboxed, stacks should not have more than four masks. Do not store heavy material on the pile.

Clean masks thoroughly whenever they are stowed or exchanged. Remove dirt with soap and water. Oil and gasoline vapors weaken the rubber and are especially damaging to the activated carbon in unsealed canisters.

Test the masks before use. You can use improvised gas chambers for periodic tests. Ensure there is enough oxygen to sustain life if an improvised gas chamber is used.

It is best to handle mask repairs at shore-based industrial facilities. In forward areas, repairs will usually amount to patching leaks in facepieces, alterations to accommodate hard-to-fit faces, and replacements of inoperable parts. Do not repair canisters; if they become inoperable, discard them and get new ones.

The following procedure is recommended for the chemical decontamination of the Mk V protective mask. It is also satisfactory for biological decontamination, but an immersion period of 15 minutes is considered adequate for that purpose.

Dip complete facepieces with head harnesses in 9 percent warm calcium hypochlorite. Leave them wet or immersed 5 minutes, then rinse thoroughly in warm (then cool) fresh water. Dry them completely in a warm to hot current of air and test for agent residue. Any cloudy condition of the eyepiece should gradually disappear as water evaporates. Test the facepieces for CW agent by placing one or more in a tightly closed metal container and leaving in a warm area (100F to 140F) for 4 hours. Sample the air in the container using a detector kit. Insert fresh canisters once the mask has been decontaminated and is to be used again. Wearers of decontaminated masks should be watched by medical personnel for eye irritation.

If a supplementary method is required, masks can be aired in a current of warm to hot air (100F to 140F), from 2 days to 1 week. Masks should be supported to minimize stretch or distortion and not allowed to come in contact with oil or grease.