Excluded are riot control agents, herbicides, smoke, and flame. Included are blood, nerve, blister, choking, and incapacitating agents. A chemical warfare agent, which produces irritation to eyes and the upper respiratory tract and damage to the lungs, primarily causing pulmonary edema. They include phosgene, diphosgene, chlorine, and chloropicrin. When the paper absorbs a drop of chemical warfare agent, it dissolves one of the pigments.
Mustard agent dissolves a red dye and nerve agent a yellow dye.
Detection paper can thus be used to distinguish between three different types of chemical warfare agents. A disadvantage with the papers is that many other substances can also dissolve the pigments. Consequently, detection papers should not be located in places where drops of solvent, fat, oil, or fuel can fall on them. Drops of water cause no reaction. The detection, identification, on-site evaluation, rendering safe, recovery, and final disposal of unexploded explosive ordnance.