There are multiple sources for identifying the DOT/IATA defined hazards of a material:

  • Shipping papers
  • Safety Data Sheets (SDS)
  • Container labels and markings.

It is also a good practice to search through the hazardous materials table listed in our references section. You can quickly find your material or its common synonym by using the ‘Find’ tool in your browser.

HazMat diamonds found on the packaging reference the DOT or IATA hazard class of the material. Some Classes include multiple hazards denoted by the division number.


Class Hazard
1.1 – 1.6 Explosives ordered by severity and sensitivity
2.1 – 2.3 Compressed Gas
3 Flammable Liquid
4.1 – 4.3 Flammable Solid, Spontaneously Combustible, or Dangerous when Wet
5.1 – 5.2 Oxidizers or Organic Peroxides
6.1 – 6.2 Toxic or Infectious Substances
7 Radioactive
8 Corrosive
9 Miscellaneous

A Packing Group may be listed next to the hazard class which denotes the relative danger of the material. The lower the group number the higher the hazard and the stricter the packing requirements. Not all classes are broken into packing groups.