Certain G-agents give a red-brown color which is intermediate between the typical H and
G colors. Decontaminants such as DS2 will turn M8 paper dark green (nearly black) and
caustic soda will turn the paper red. Caution should be taken in interpreting M8 paper
color changes when DS2 and caustic soda are in the area being sampled.
30. Sampling for Unknown Agents
When no positive tests are obtained with the preceding tests and the presence of chemical agent is suspected-
a. Complete a report card. Be sure to record information which may be helpful in determining the nature of the
unknown agent, such as identification of the unit taking the samples; the place, date, and time the samples are taken;
observed characteristics of the agent, and the effect of the agent on men. List the observed color effects on the various
types of detector tubes.
b. Select an area for sampling that is likely to have a high concentration of agent (a depression in the ground or
just above a puddle of liquid agent). Take samples in five white-band sampling tubes. The instructions given below apply
to each of the five sampling tubes.
(1) Snap both ends from a white-band sampling tube at the scoring and press the unmarked end into the
(2) With the sampling tube pointing down, compress the bulb sixty times.
(3) Remove the sampling tube from the adapter and place it in the envelope containing the completed report
c. Place the five sampling tubes and the report card in an envelope, seal the envelope, and forward to the
chemical laboratory designated in the unit's SOP.
31. Summary of Tests