This Allied Publication defines a tube furnace test method for determination of TOXICITY INDEX values for combustion gases@ evolved from small specimens of materials@ separately@ under each of two sets of specified ignition conditions. This Allied Publication is intended to form part of the pre-selection screening process for materials and should not be interpreted as an assessment of toxicity hazard under actual fire conditions. The test method is directed at the analysis of a specified set of gaseous species which are commonly present in combustion products of materials used in military applications and which may cause lethality at the time of the fire. It does not address acute mental incapacitation effects@ delayed/long term toxicity@ or toxicity involving particulate combustion products. The set of gaseous species analysed is not exhaustive and other toxic species@ not yet listed@ can be evolved from common materials. The current list represents a set designed to give a general assessment of the toxic hazard.