Airplanes and airports are in potential danger during transport of highly toxic chemicals, and accidents can occur if the wrapping material is damaged. The chemicals are listed and classified by the International Civil Aviation Authority ICAO) (7). They are subdivided into nine classes, each marked by a special symbol. The classification is derived from the most important properties of the chemicals in relation to the air transport (Table 1). Special positions are listed in class 6. This does not mean, however, that the chemicals of all other classes are non-toxic. On the contrary, highly toxic substances also exist in each other class. For example, class 2 “compressed gas” includes dangerous toxic substances such as hydrochloric acid, fluorine, carbon monoxide or sulphur dioxide. Class 3 (“flammable liquids”) includes benzene, methanol, acrylonitrile and ethyl methyl ketone, for example. In class 6 (“poisons”), special poisons are listed such as tetraethyl lead, dimethyl mercury, organophosphates and aniline. Class 8 (“corrosives”) consists of poisons like bromide, dimethyl sulphate, phorphorous trichloride and hydrofloric acid.