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This appendix addresses nuclear, biological, and chemical defense; mission-oriented protection postures; and decontamination. NBC weapons produce casualties and disrupt operations. Platoons must be prepared to operate in an NBC environment during any operation.


To defend against NBC weapons, soldiers must apply the three fundamentals of NBC defense: avoidance, protection, and decontamination. FM 3-100 contains a general discussion of NBC defense measures. FMs 3-3, 3-4, and 3-5 contain detailed information.


The first fundamental of defense against NBC weapons is contamination avoidance. If soldiers can avoid contamination, they decrease the need for protection.

Take Passive Measures

Use concealment, so the enemy cannot find you, or disperse so you make a poor target. You can also harden your position by improving its cover. Other passive measures include operations and communications security.


Nuclear, Biological, and Chemical Defense Fundamentals

Nuclear Defense

Chemical Defense

Biological Defense

Mission-Oriented Protection Posture


Detect and Identify Hazards

Monitor for contamination. Reconnoiter and survey specific areas to determine contamination status. Listen to higher and supported unit nets for reports of contamination or enemy NBC use. Enemy intentions may be discerned by identifying the type of agent. Also, identification gives the platoon an idea of what type of decontamination support is required. If the agent is nonpersistent, weather will reduce it to nonthreatening levels in minutes or hours. There is no need to request decontamination units for nonpersistent agents. Decontamination will consist of an operator spraydown using a decontaminating solution applied with an M11 or M13 portable decontamination apparatus. Periodic monitoring with chemical detection paper (M8 and M9) and the M256 chemical detection kit will identify any agent present in threatening concentrations. In a nonpersistent agent attack, the unit may only have to remain in MOPP 4 for 30 minutes or less.

Use the NBC Warning and Reporting System

When a hazard is detected, pass the alarm locally. Mark the contaminated area with NATO standard US markers, and report to higher headquarters using standard NBC reports.

Limit Contamination

Cover mission-essential equipment using readily available material. Restrict personnel movement in the contaminated area.

Move From the Contaminated Area

The unit must move if the tactical situation allows. The direction and route of movement can be obtained from higher headquarters. This reduces the overall contamination hazard; however, soldiers must be careful to avoid spreading contamination during movement.


The second fundamental of defense against NBC weapons is protection. It is required when contamination cannot be avoided. See FM 3-4 for a detailed discussion of personnel and selected equipment protection. Four broad groups of activity can be emphasized as protective measures: hardening positions, using MOPP, reacting to attack, and using collective protection.


The third fundamental of defense against NBC weapons is decontamination. It reduces the contamination hazard by removing or neutralizing hazardous levels of NBC contamination on personnel and materiel. The extensive time and logistical support needed to perform deliberate decontamination operations mandates avoiding contamination, if possible.


Nuclear weapons are tremendously powerful, but defensive measures can be taken to reduce their effectiveness. The more information known about nuclear weapons, the more effective the defense, and the greater the chances of survival.


Cover is the best protection against a nuclear attack. Fighting positions, armored vehicles, heavy structures (concrete, stone, or brick), culverts, and other underground areas provide excellent protection. Light-skinned and wheeled vehicles offer very little protection. Weapons, individual equipment, clothing, supplies, ammunition, explosives, petroleum products, and other flammables should be safeguarded. These items should be secured in one of the protected areas listed above. Nuclear defense levels for possible, likely, and imminent conditions are described in the Nuclear Defense Levels illustration.


When operating in a radiologically contaminated area, vehicles should be buttoned up, sandbagged, and the cargo covered. If the mission permits, personnel should be closely monitored to ensure compliance with operational exposure guides. The radiation exposure status should be updated.


Immediately secure cover while in a prone position and protect exposed skin until blast waves have passed and debris has stopped falling. Stay calm, check for injuries, check weapons and equipment for damage, and prepare to continue the mission.


Once the attack has ended, forward an NBC-1 nuclear report, and consolidate and reorganize the AD position. Improve protection against possible fallout by seeking overhead cover for vehicles and begin continuous monitoring. If the radiation dose rate reaches a hazardous level, request permission to move.


Various injuries may result from nuclear attack. Soldiers must be prepared to administer first aid as described in the following paragraphs.

Blast Injuries

Damage can range from minor cuts and broken bones to severe lacerations and critical damage to vital organs. First aid treatment will be the same as that used for conventional combat casualties suffering similar injuries.

Thermal Radiation Injuries

The intense heat generated by a nuclear detonation burns skin, clothes, and equipment. Injuries can be caused by direct exposure, reflected exposures (from clouds and ground), and from secondary sources, such as burning debris. These burns are categorized as first-, second-, and third-degree. First-degree burns should heal without special treatment, and there will be no scar formation. Casualties of a second-degree burn, which resembles a severe sunburn with blistering, are treated as burn casualties to prevent infection. These casualties may require evacuation. In third-degree burns, the full thickness of the skin is destroyed. The casualty should be treated and evacuated.

Eye Injuries

Thermal radiation's effect on the eyes falls into two categories: temporary blindness (dazzle) and permanent blindness. Individuals temporarily blinded will recover with time, but will require assistance until their sight returns. Individuals suffering permanent damage should be evacuated as soon as possible.


Individuals may react differently to radiation exposure, but generally, individuals can be expected to react similarly to certain dose ranges as shown in the Radiation Dose Levels illustration.

Symptoms of radiation exposure include vomiting, diarrhea, dry heavy nausea, depression, and mental disorientation. At lower dose levels, incapacitation and lethargy occur due to a loss of physical mobility or mental disorientation. At higher dose levels, shock and unconsciousness are the early symptoms.

Mechanical injuries such as broken bones, internal injuries, and burns are more serious when the casualty has received minor doses of radiation. Every effort should be made to identify casualties who have been exposed to radiation.


Platoons exposed to radiation must measure the total dose using the IM93 dosimeter and send dosimetry (exposure) reports to the commander. Commanders must identify units that exceed the operational exposure guidance.

Team members contaminated by radioactive dust or debris perform partial decontamination by brushing, wiping, and shaking debris from their bodies and gear. Contaminated vehicles are partially decontaminated by brushing or washing. This limits the spread of contamination and reduces radiation hazard. Early decontamination is necessary to diminish the cumulative effects of radiation.


Chemical agents are used to kill, injure, or incapacitate personnel. The effects produced by these agents are dose-dependent. Through the use of various delivery systems, enemy forces can initiate and sustain large-scale chemical warfare operations.


Make sure all personnel have their protective mask available and that it fits and functions properly. All personnel should be wearing protective clothing according to the designated MOPP level. The M8 automatic alarm should be put into operation for chemical monitoring and detection.


Mask and give the alarm. Get into MOPP 4 as soon as possible. Use chemical agent detector paper and M256 chemical detector kits to determine type of agent and forward an NBC-1 report; decontaminate skin and equipment; and continue the mission.


Certain defensive actions must be taken following a chemical attack. Perform individual decontamination as required, treat casualties, and then complete basic individual decontamination.


Biological agents consist of microorganisms and toxins. Microorganisms are germs that cause diseases. Toxins are poisons produced by plants, animals, or microorganisms. Biological agents, including toxins, can cause death and disease. It is not necessary for biological agents to kill to be effective. Their purpose may only be to reduce the ability of our forces to fight.


Biological attacks are difficult to detect. Sunlight reduces the effects of biological agents. Based on this, the most likely time for a conventional biological attack is in the evening and early morning hours. Some toxins are not sensitive to environmental factors and could be employed in any type of environment.


The best defense is to observe preventive measures such as keeping immunizations up-to-date, maintaining personal hygiene, eating and resting regularly, and providing rodent and insect control. Keep cuts or scratches covered and germ-free by using soap, water, and first aid. Insects carry biological agents. Prevent insect bites by keeping clothes buttoned, covering skin, and using insect repellent.

After an attack, you must assume everything has been contaminated. Only eat rations that have remained sealed. Wash the outside of food and water containers before opening. Use only water from quartermaster water supply points. In emergencies, boil all water for at least 15 minutes or use water purification tablets. Do not use water exposed to toxins or spore-forming microorganisms.


Protective actions against biological and chemical agents depend on the threat, mission, situation, and weather. As with nuclear protective actions, chemical and biological protective actions fall into three categories: action before the attack, during the attack, and after the attack.


Commanders establish MOPP levels depending on the risk of NBC attack. They use MOPP analysis to determine appropriate MOPP levels based on the tactical situation.

Standardized MOPP levels allow commanders to easily increase or decrease levels of protection. They can raise or lower the amount of protection through five levels of MOPP--MOPP0 through MOPP4. Commanders may not implement a MOPP level lower than that set by higher headquarter.

The Avenger platoon must understand and apply MOPP levels, when required, for protection and survival. See the Standardized MOPP Levels illustration. STP 21-1-SMCT has further guidance on wearing MOPP gear.


The Individual and Unit Actions illustration below shows individual and unit actions that must be completed at different MOPP levels prior to an attack. Commanders may modify specific postures to permit mission accomplishment.


Leaders must check their soldiers for proper fit and seal of protective masks and fit of protective clothing. Soldiers must assume stressed positions (bending, twisting, and stretching) to check fit. Compliance with the MOPP level should be checked regularly.

Stress and fatigue can be reduced by rotating heavy work requirements. Allow frequent rest periods, make maximum use of mechanical aids, and provide adequate water supply.


Decontamination is essential in preventing casualties and combat degradation in a contaminated environment. In the past, when a unit was contaminated, it was withdrawn from battle and went through an 18-hour decontamination to remove all traces of contamination. Tactically and logistically, this approach may not be feasible.


All personnel need to be familiar with chemical and toxic agents. Being able to distinguish different types of agents will aid in making rapid and educated decisions regarding methods of decontamination.

Immediate Decontamination

The three techniques for immediate decontamination are--

  • Skin decontamination.
  • Personal wipedown.
  • Operator's spraydown.

Skin decontamination is a basic soldier survival skill. When chemical and toxic agents get on bare skin, it is an emergency. Some of these agents can kill if they remain on the skin for longer than a minute. The best technique for removing or neutralizing these agents is to use the M291 or M258A1 skin decontamination kit and continue to monitor the soldier for symptoms after skin decontamination is conducted. The CAM or M8 paper may be used initially to identify nerve of blister type of agents (see TC 3-4-1).

Personal wipedown should begin immediately after skin exposure to liquid contamination or when exposure to liquid contamination is suspected. The wipedown removes or neutralizes contamination on the hood, mask, gloves, and personal weapon. Skin decontamination kits are used for chemical and biological contamination. Soldiers should decontaminate only what is necessary, conserving the CAM and M8/M9 paper and saving time. For radiological contamination, soldiers wipe the contamination off with a cloth or simply brush or shake it away.

Operator's spraydown should begin right after finishing the personal wipedown. The spraydown removes or neutralizes contamination on the surfaces of the equipment that operators must frequently touch to perform their mission. For chemical and biological contamination, operators use onboard decontamination apparatuses like the M11 or M13. Operating the CAM or using M8/M9 paper will assist in determining what is contaminated. Again, it is important that the soldier conserve time and resources.

For radiological contamination, the soldier should brush or scrape the contamination away with whatever is at hand or flush with water and wipe.

Operational Decontamination.

Operational decontamination includes vehicle washdown and MOPP gear exchange. Operational decontamination allows a force to fight longer and sustain its mission while contaminated. It limits the transfer hazard by removing most of the gross contamination on equipment and nearly all of the contamination on soldiers. This speeds the weathering process and allows clean areas, equipment, and people to stay clean. Vehicle washdown can be executed using the concept of supported or unsupported operational decontamination. The contaminated unit (battalion or task force) performs unsupported decontamination using unit decontamination equipment and personnel. This process requires no external support or resources. The unit performs supported washdown with support from a chemical company. The chemical company mission support priorities will be established by the applicable OPORD available to the platoon through normal procedures.

MOPP gear exchange involves soldiers changing their contaminated gear for clean sets at the operational decontamination site. The squad, section, and platoon are responsible for supervising and conducting their own MOPP gear exchange during hasty decontamination or when the commander authorizes it. Vehicle washdown involves using M12A1 power driven decontamination apparatus (PDDA) or the M17 lightweight decontamination system (LDS). This technique should be completed within one hour.

Thorough Decontamination

Thorough decontamination includes troop decontamination and detailed equipment decontamination. Detailed troop decontamination (DTD) is the process of decontaminating individual fighting equipment to negligible risk levels. Soldiers will remove contaminated MOPP gear to include their protective masks. Protective masks will be decontaminated, and personal equipment will be monitored for decontamination effectiveness. The contaminated unit conducts deliberate troop decontamination with some technical assistance from the chemical unit or unit chemical personnel.

Thorough decontamination operations reduce contamination to operations reduce contamination to negligible risk levels and restore combat power by removing nearly all contamination from unit and individual equipment so troops can operate equipment safely for extended periods at reduced MOPP levels. A small risk from residual contamination remains, thus periodic contamination checks must be made by leaders. More information concerning levels of decontamination can be found in FM 3-5.


Seven decontamination techniques are used to support the three types of decontamination. The following illustration lists the techniques for each decontamination level.

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