The US Department of Transportation (DOT) classifies hazardous materials according to the risks that they pose. There are nine hazard classes:
- Class 1: Explosives
- Class 2: Gases
- Class 3: Flammable liquids
- Class 4: Flammable solids
- Class 5: Oxidizers/organic peroxides
- Class 6: Toxic and infectious substances
- Class 7: Radioactive material
- Class 8: Corrosives
- Class 9: Miscellaneous hazardous materials
Within class 6 are two divisions:
- Division 6.1- poisonous material
- Division 6.2- infectious substance
A division 6.2 infectious substance is defined as a material known or reasonably expected to contain a pathogen.
A pathogen is a microorganism or other agent (e.g., a prion) that can cause disease in humans or animals.
The regulations that govern packaging and shipping a class 9, miscellaneous hazardous material, may also need to be reviewed by those who package and ship laboratory specimens. Dry ice is a class 9 hazardous material and, if used, requires special packaging, and specific labeling and marking on the outer package.
