 In modern warfare there is always a strong probability that the enemy will launch a chemical or biological attack whenever it suits his purpose to do so. It follows therefore that in any tactical situation, a great deal of your combat effectiveness will depend upon your ability to protect yourself against all varieties of agents. The purpose of this film is to show you the correct procedures for masking and the various basic circumstances under which you will mask automatically without command. Every individual should be trained to put the mask on correctly in 9 seconds or less. This training will enable you to follow the automatic masking procedure when the need arises. The procedure for masking under CBR conditions include three important steps. Stop breathing, mask, and continue your mission. Let's look at some of the ways the enemy may use to spread chemical and biological agents. By bombs, artillery fire, mortar fire, rockets, aircraft spray, and smoke. When chemical or biological operations are begun or suspected and your position is under attack, mask immediately. Don't wait for a command or alarm. Stop breathing, mask, continue your mission. Keep your mask on until ordered to remove it. Unmasking is a command decision. Toxic chemical agents affect you in various ways. If you suddenly develop a runny nose without any apparent cause, mask immediately. If you experience difficulty in breathing, a sudden feeling of choking or tightness in the chest, mask immediately. Without apparent reason, your eyes become irritated. Mask immediately. An unaccountable dimming of vision or difficulty in focusing the eyes on close objects, mask immediately. In any tactical situation, when an unusual liquid or odor is present, mask without delay. Then use the detector kit to determine whether a toxic chemical agent is present and to identify the agent. Through intelligence and other channels, your unit leaders will normally be alerted as to when and where toxic agents may be expected or have previously been used. Beyond the alert for areas posted with contamination markers. If you approach the contaminated area from the downwind side, mask immediately. If your mission permits, bypass the area. Even though you may be in an area which is clear of contamination, always keep your mask within easy reach and never fail to use your unit's detection device for determining the presence of toxic chemical agents. Most toxic chemical agents are invisible and odorless. For timely detection of their presence, you can't depend on your senses alone. When you hear an alarm, don't wait for a command. Mask immediately, automatically, regardless of whatever you may be doing. The mask is your most important piece of equipment when chemical or biological agents are used. It will stop these agents from entering your body through your nose, mouth and eyes. Depend on your mask. It is your best protection. You must know how to put it on properly and rapidly. And above all, you must know when to put it on.