The amount of a chemical agent present in a unit
volume of air. Usually expressed in milligrams per cubic meter (mg/m3) of
10. Decontaminating Material.
Any substance used to chemically destroy,
physically remove, seal, or otherwise make a chemical agent harmless.
The determination of the presence of a chemical agent.
12. Dosage (Ct). The concentration of a chemical agent in the atmosphere
(C) multiplied by the time (t) the concentration remains, expressed as
mg-min/m3 or the cumulative exposure equivalent to the concentration of
chemical agents to which and individual is exposed, integrated over the time
The dosage received by a person depends upon how long the
person is exposed to the concentration. That is, the respiratory dosage in
mg-min/m3 is equal to the time in minutes an individual is unmasked in an
agent cloud multiplied by the concentration of the cloud. The skin dosage
is equal to the time of exposure in minutes of an individual's unprotected
skin multiplied by the concentration of the agent cloud. (This is generally
understood as being the effect upon the whole body.) The physiological
effectiveness of skin and respiratory aerosol dosages are influenced by
particle size as well as time and concentration, since retention by the
lungs and impingement upon the skin are functions of particle size.
are usually expressed in mg-min/m3 for a particle size.
13. Liquid Dosage. The weight of liquid agent received by a person on the
skin is usually expressed as dosage in milligrams of contaminant per
kilogram (kg) of body weight (mg/kg).
This is equivalent to parts per
Actually, an individual may show signs and symptoms
after exposure to a chemical agent which are less or more than expected for
a given dosage (Ct), depending upon some of the following variables:
a. How long the breath was held during short exposure.
b. Speed with which mask was donned.
c. Ability to fit mask and mask leakage factors.
d. Whether the chemical agent was also absorbed through the skin.
e. Whether the chemical agent stimulated the rate of breathing.