(a) This term includes those acids, alkaline caustic liquids, and other corrosive liquids which, when in contact with living tissues, will cause severe damage of such tissues, by chemical action; or in case of leakage, will materially damage or destroy other freight by chemical action, or are liable to cause fire when in contact with organic matter or with certain chemicals.

(b) A corrosive substance may be:

(1) Solid, such as iodine; or,

(2) Liquid, such as acids, or caustic soda solution; or,

(3) Gaseous, such as chlorine or sulfur dioxide.