Class 5 includes oxidizers (substances which yield oxygen to
stimulate the burning of other materials [chlorate, nitrate,
Class 6 includes irritants and poisons. As the name suggests,
irritants are materials which give off irritating fumes.
Poisons are divided into two groups:
- "A" poisons are those which are dangerous to life in small
- "B" poisons are toxic to man.
Class 7 includes radioactive materials which may be any
material or combination of materials that spontaneously emit
Class 8 includes corrosives such as acids or other substances
which will destroy human skin.
Class 9 includes all the other miscellaneous dangerous
substances which do not fall into the preceding categories.
In addition to the classes, the DOT system may be used as well to
numerically list hazard classes.
This system groups materials into
11 major hazard classes:
(1) Explosives (as described earlier, Classes A, B, and C, plus
(2) Compressed gases, both flammable and nonflammable.
(4) Flammable solids (further broken down into
water-reactive, or spontaneously combustible).
(6) Organic peroxides.
(7) Etiologic agents, defined as viable microorganisms or toxins
which cause or may cause human disease. (The chief etiologic
agents found in transport are biological specimens and virus
specimens used for testing and research.
The latter include
such agents as measles or rabies viruses.)