Triage of casualties of chemical agents is based on the same principles as the triage of conventional casualties. The triage officer tries to provide immediate care to those who need it to survive; he sets aside temporarily or delays treatment of those who have minor injuries or do not need immediate medical intervention; and he does not use limited medical assets on the hopelessly injured. At the first echelon of medical care on a battlefield, medical capabilities are very limited. When chemical agents are present or suspected, medical capabilities are further diminished because early care must be given while the medical care provider and casualty are in protective clothing. Decontamination, a time-consuming process, must be carried out before the casualty receives more definitive care, even at this level. At the rear echelons of care--or at a hospital in peacetime--medical capabilities are much greater and decontamination has already been accomplished before the casualty enters for treatment. Triage is a matter of judgment by the triage officer. This judgment should be based on knowledge of medical assets, the casualty load, and, at least at unit-level MTFs, the evacuation process. Most importantly, the triage officer must have full knowledge of the natural course of an injury and its potential complications.
Textbook of Military Medicine: Medical Aspects of Chemical and Biological Warfare, p. 337-349