HC 101 – Introduction to Hazard Classification

HAZMAT Shipping Guidelines: what is a hazard classification and why is it needed?

In 1975, Congress published the Hazardous Material Transportation Act (HMTA), the purpose of which is to provide protection against risks inherent in the commercial transportation of hazardous materials by introducing and improving regulations and increasing the enforcement authority of the Secretary of Transportation. Shipments containing hazardous materials, including those being shipped to sites for testing or analysis, or to an associate for research, must adhere to applicable shipping requirements.  To comply, regulated materials are classified according to the hazard that they present.  Packaging, labeling, handling, and shipping requirements are determined by which classification is obtained.

What are hazardous materials?

A hazardous material (often called “dangerous goods” outside the US), as defined by the Department of Transportation, means a “substance or material that the Secretary of Transportation has determined is capable of posing an unreasonable risk to health, safety, and property when transported in commerce, and has been designated as hazardous under section 5103 of Federal Hazardous Materials Transportation Law (49 U.S.C. 5103).” This can include explosives, hazardous substances, hazardous waste, marine pollutants, and elevated temperature materials. Also included are laboratory chemicals, radioactive materials, compressed gases, biological agents, diagnostic specimens, refrigerants, and instruments or equipment that might contain hazardous materials.

Most hazardous materials are self-classified, but explosives’ classification must be approved by DOT. That approval is based on the recommendation of an approved test lab like APT. If a substance or article is designed to produce an explosive or pyrotechnic effect, the shipper must have it approved for classification in Class 1 by DOT (with limited exceptions). Even if a substance or article is not designed to produce an explosive effect, but may have explosive or pyrotechnic properties, the shipper must consider whether the substance or article might meet the criteria for Class 1.

How do I know if a material is covered by the regulations?

It is the shipper’s responsibility to identify the material and provide information on physical characteristics (flash point, pH, weight/volume, etc.). This will assist APT to properly classify materials that are subject to the Hazardous Materials Regulations (HMR). To determine if a material is regulated, the following references in 49 CFR are checked to see if the material is listed:


APT Point of Contact

Melissa Emery, 256.327.3373
HCinfo@apt-research.com