Of the two types, a false negative detection is more serious because it can lead to an exposure to a chemical warfare agent that might otherwise be preventable. Extensive testing with known chemicals and compounds normally found on a battlefield indicate that a false negative detection, although possible, is unlikely. However, a false positive detection can occur if an outdated kit is used, if a kit is inadvertently exposed to some battlefield pollutants, or if the kit is used improperly. The US inventory of detection equipment runs the gamut from highly technical automatic sensors and forward-looking infrared devices to manually operated detectors such as the M256 detection kit. Today, a variety of CWA detection equipment is used throughout the world.
Some countries use identical equipment.
For example, both the US and Canadian armed forces use the M256 detection kit. Other countries, e.g., the United Kingdom and Germany, use CWA detectors of their own design, but capable of achieving the same results as the M256 detection kit. Throughout much of recorded history, toxic chemicals or substances have been used as weapons of war. In 1969, the US stopped the development and manufacture of CWAs. Today, the US continues to develop CWA protection and CWA detection equipment.