NBC Decontamination

The Nuclear, Biological, and Chemical (NBC) fundamentals published in this manual provides detailed guidance on conducting decontamination operations; and can be performed by chemical and nonchemical personnel. Survivability and reducing the effect of any chemical threat are the ultimate goals of NBC decontamination.

The use of NBC weapons creates unique residual hazards that may
require decon. In addition to the deliberate use of these weapons, collateral damage, natural disasters, and industrial emitters may require decon. The presence of contamination generally reduces the effectiveness of our combat power. Contamination forces us into protective equipment that degrades our ability to perform individual and collective tasks.

CONTAMINATION FORMS
1-1. The following are the different forms of contamination:

• Solids - radioactive particles, biological spores, or dusty agents that could appear as a fine dust.

• Liquids - liquid droplets that fall like rain. Droplets can range from
thick and sticky to the consistency of water.

• Vapors or gases - created by bursting munitions or generators. These clouds are affected by the weather and can cover large areas.

• Aerosols - fine liquids or solid particles suspended in the air. They
behave much like vapors.

CONTAMINATION-HAZARDS TRANSMISSION
1-2 Contamination hazards can be transmitted in the following manner:

• Transfer. Anything that touches a surface covered with liquid or
solid contamination will tend to pick up that contamination and move it from one surface to another.

• Spread. Touching a surface covered with liquid chemical agent can
spread contamination on the same surface, thereby, increasing the
size of the contaminated area.

• Vapor. Vapors can be carried through the air in the form of a dust,
atomized liquids (aerosols), or true gases. Vapors in an open/outdoor
area disperse rapidly, so there is no need to decon.

• Desorption. Liquid-chemical contamination absorbs into porous
surfaces. Once absorbed, it begins to desorb or give off gas; that is, low levels of vapor pass out of the contaminated surface into the air and can be transferred to any surface that contacts it, including bare skin.

• Radiation. Radiation is given off by radioactive dust or dirt, most of
which appears as fallout. For decon purposes, radiation can be thought of as a solid.

AGENT CLASSIFICATION
1-3. Depending on the length of time agents will be a hazard, they are
classified as--

• Nonpersistent - an immediate threat that lasts a few minutes. They
rarely require decon.

• Persistent - takes a longer time to act and may last for days. In a
protected environment, these agents can last for long periods of time.
All agents are affected to some extent by the weather. Even
radiological particles can “rain out” of the air and form hot spots on
the ground. Biological organisms are greatly affected by sunlight.
Chemical agents can be decontaminated by the weather. The duration
of a hazard is a complex estimation that is based on numerous factors
which include the -

Type of contamination.
Contamination density and droplet size.
Temperature.
Wind speed.
Sunlight.
Humidity and rain.
Composition of the contaminated surface.
Type of soil and terrain.