Numerous detectors and alarms were used in the Gulf War to alert troops to the
presence of chemical weapons. The trouble is that all can be 'set off' by other
compounds, some of which are very common. The substances that cause false
positives are called interferences.
Unfortunately, petroleum products can be mistaken for sarin in this preliminary
analysis. Once a suspicious reading is obtained, the vehicle is supposed to
stop, cool down its probe and carry out a full spectrum analysis to confirm the
identity of the substance. Only if a full spectrum analysis is done can the
operators be sure they have found a chemical agent and not an interference.
the Gulf War, many of the Fox vehicles drove along with tank convoys and did
not have time to carry out the full analysis to confirm, or reject, their
- One low-tec detections system is a chemically sensitive paper that
servicemen wrap around their wrists and ankles. M8 and M9 paper changes color
in the presence of nerve and blister agents. It also changes color in the
presence of organic solvents like bug sprays.
- Much more reliable is the M256A1 Chemical Agent Detector Kit, which enables
the user to chemically test for chemical agent in both a vapor and liquid form.
But even here, pesticides, smoke and strong bleach can produce false positives
for sarin and mustard, so manuals require the test be repeated.
- Throughout the war, the main chemical alarm used was the M8A1 Automatic
Chemical Alarm. It was sensitive but not precise. Diesel exhaust, obscuring
smoke and signal smoke can produce false positives.
- The Chemical Agent Monitor (CAM) was used to find blister agent on the
surfaces of vehicles and buildings. Interferences that give false positives
include: after-shave, perfume, liquid cleaning solvents, signal smoke and
- The top-of-the-line detector is the FOX NBC Reconnaissance System from
Germany. These vehicles have an on-board mass spectrometer. Designed to scout
the terrain ahead of the fighting troops, it uses a trailing wheel to sample
the surface continually looking for chemical agents. The wheel touches against
a probe and the on-board mass spectrometer makes a first "guess" as to what the
substance might be.
join the discussion .
analyzing the major theories .
five interviews .
the veterans .
a closer look .
examining the media's role .
a guide to the site .
comparing gulf veterans' health with other veterans .
tapes & transcripts .
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