The Inhalation Hazard Test; principle and method.

The Inhalation Hazard Test (IHT) measures the hazard rather than the toxicity of volatile substances. Generation methods for saturated vapor atmospheres and exposure systems are described. The determination of the nominal concentration gives in most cases sufficient information on the concentration in the inhalation atmosphere. The temperature at which the saturation occurs and the exposure time are parameters which influence the test results. The determination of the LT0 (the exposure time at which no animals die) is used to compare substances with different inhalation hazards. A classification system is proposed to differentiate the toxic hazard of volatile substances. The IHT is an appropriate method to characterize the acute inhalation hazard of volatile substances. It requires fewer animals and is less elaborate than the LC50.