Hazard Identification : Each United Nations hazard class (with the exception of class 9) has a distinctive diamond shaped label bearing a pictogram for quick hazard recognition. Figure gives a colour chart for all the classes and subclasses.
Each label has a characteristic background colour. These colours convey the nature of different chemical substances as given below.
Colour Nature
Orange Explosive
Red Flammable
Blue Water reactive
Yellow Oxidiser
White Toxic or Infectious
White or Yellow and White Radioactive
Black and White Corrosive
All the classes are discussed briefly in the following paragraphs.