in  the  absence  of  sunlight  or  daylight,  the impregnation treatment should remain effective for 5 to 10 years or more. NOTE: Impregnated clothing is being phased out  and  will  be  replaced  with  the  chemical- protective overgarment. Chemical-Protective Overgarment The chemical-protective overgarment consists of two pieces—a smock and trousers (fig. 6-9). The smock has two layers of materials: inner (antigas)  and  outer  (modacrylic/nylon).  The smock  is  generously  cut  to  allow  complete freedom of movement. It has a large front flap pocket for gloves and so forth and a sleeve patch where you can place detector paper for easy visibility. You can make quick and easy adjustments with hook-and-pile fasteners at the wrist and waist. The trousers are made of the same two layers of material and have suspender-type fittings located at the waist and across the shoulders. Hook-and-pile fasteners are located at the base of each leg for adjustment. Figure 6-9.-Chemical-protective overgarment. The chemical-protective overgarment is issued in a plastic envelope that is pressure packed, air evacuated, and heat sealed. It is then placed in a polyethylene bag and heat sealed. The over- garment has a shelf life of 5 years when unopened. The protective overgarment protects against all CBR agents and is permeable to water vapor. Once removed from its protective envelope, it has a shelf life of 14 days in a nonchemical environ- ment. If it is opened but uncontaminated, keep it for training purposes. Once exposed to chemical contamination, the overgarment provides 6 hours of continuous protection, after which it should be discarded. The following donning procedures include the use of the chemical-protective glove set and footwear  covers  (overboots): 1. 2. 3. 4. 5. 6. 7. 8. Don the trousers. Tighten the waist by using the hook-and-pile fasteners. Bring the straps over the shoulders and cross them at the chest. Insert the straps into the belt loops and secure snugly. Don the parka. Secure the bottom of the parka with hook- and-pile straps. Raise the trouser legs. Don  the  chemical-protective  footwear cover (see fig. 6-10). a. b. c. d. e. f. g. Attach tie laces (in the center) to the toe loop. Be sure the laces are even (see fig. 6-10, view 1). Put  one  lace  through  A  and  one through B from the inside to the out- side and pull until snug. Make sure the toe loop is over the top of your shoe (see fig. 6-10, view 2). Put  one  lace  through  C  and  one through D (on the opposite side of the foot, crossing the instep) from inside to outside. Pull until snug (see fig. 6-10, view 3). Cross the laces over the instep. Thread  the  laces  through  A  and  B again, from inside to outside (see fig. 6-10, view 4). Cross the laces over the instep again and pull them until snug. Wrap the laces behind the ankle and back to the front. Pull until snug and tie securely (see fig. 6-10, view 5). Pull the trouser legs down over the footwear covers and secure with the hook- and-pile fasteners. Don the mask. 6-18