Butyl rubber masks

Wear full protective clothing consisting of the M3 butyl rubber suit with hood, M2A1 boots, M3 gloves, treated underwear, M9 series mask and coveralls (if desired). Wear gloves and lab coat with M9, M17, or M40 mask readily available for general lab work. 

OTHER PROTECTIVE EQUIPMENT Full protective clothing will consist of M9 mask and hood, butyl rubber suit (M3), M2A1 butyl boots, M3 and M4 gloves, unimpregnated underwear, or demilitarization protective ensemble (DPE). For laboratory operations, wear lab coats and have a protective mask readily available. 

Unfortunately, silicone rubber offers rather low resistance to the penetration of common chemical agents. Perfluorocarbon rubber is very impermeable but is expensive and tears easily. Butyl rubber offers both good protection and seal and has therefore become the material of choice.7 Even this description of materials used to construct the faceblank underestimates the complexity of actual mask design. In today s standard U.S. military masks, the faceblank consists of two separate layers an inner later made of silicone rubber (for maximum seal) and an outer layer made of butyl rubber for maximum protection (Figure 16-2). 

Fig. 16-2. The M45 protective mask facepiece has two skins. The inner skin is composed of silicone rubber, and the outer skin is composed of butyl rubber. This arrangement maximizes both mask-to-skin seal and chemical agent impermeability. A similar design is used in the M40 protective mask. Photograph Courtesy of Visual Information Division, US Army Chemical and Biological Defense Command, Aberdeen Proving Ground, Md.

N-Butyl Acetate All-purpose canister mask, chemical safety goggles, rubber gloves. Remove from exposure immediately. Call a physician. If breathing is irregular or stopped, start resuscitation, administer oxygen. In case of contact, flush with water for at least 15 minutes. 

Tert-Butyl Alcohol Air pack or organic canister mask, rubber gloves, and goggles. Remove victim from exposure and restore breathing. Remove liquid from skin with water. Flush eyes with water. 

An important question of mask design is the composition of the elastic material used to cover the face the faceblank. The first masks introduced in World War I were made of rubberized cloth or leather. Subsequent masks used natural rubber, but recently, sophisticated synthetic polymers using silicone, butyl, and perfluorocarbon rubbers have been used.6 Silicone rubber has the advantage of making possible a tight fit or seal between the mask and skin, with a correspondingly decreased potential for leaking (a factor said to be responsible for about 5% of mask failures).12... 

The facepiece of the M43 Chemical-Biological Aircraft Mask is fabricated of bromo butyl and natural rubber with an integral butyl hood and skull-type suspension system (Figure 16-10). The M43 has two models, designated Type I and Type II. The two models are identical with the following exceptions Type I has a notch in the right eyepiece that accommodates a special sighting device used by Apache helicopter pilots, and uses a different microphone for communication Type II has two spherical lenses and uses a dynamic microphone. Both microphones interface with the helicopter communications systems. 

---