When shipping hazardous materials, understanding DOT hazard classes helps shippers identify risks, select appropriate packaging, and follow transportation regulations. How many hazard classes are there for fully regulated items? The U.S. Department of Transportation (DOT) recognizes nine primary hazard classes, with some classes divided into smaller categories.
How Does the DOT Regulate Hazardous Goods?
The DOT regulates hazardous materials through its Hazardous Materials Regulations (HMR), primarily found in 49 CFR Parts 171–180. Requirements depend on the material and shipment and may include:
-
Identification and classification: Determine the material’s proper shipping description and hazard class.
-
Hazard communication: Use required shipping papers, labels, markings, and placards.
-
Packaging requirements: Use authorized packaging that meets applicable standards.
-
Safe handling and transportation: Follow relevant rules for preparing, loading, handling, and transporting hazardous materials.
How Many Hazard Classifications Are Used By the DOT?
DOT recognizes nine main hazardous materials classes. Each class represents a different type of transportation hazard.
-
Class 1 — Explosives: Materials or articles that present an explosive hazard.
-
Class 2 — Gases: Includes flammable, non-flammable, and toxic gases.
-
Class 3 — Flammable Liquids: Liquids that can ignite under specified conditions.
-
Class 4 — Flammable Solids: Includes flammable solids, self-reactive materials, and certain materials dangerous when wet.
-
Class 5 — Oxidizers and Organic Peroxides: Substances that can cause or intensify combustion.
-
Class 6 — Toxic and Infectious Substances: Materials that may pose poisoning or infectious risks.
-
Class 7 — Radioactive Materials: Materials regulated because they emit ionizing radiation.
-
Class 8 — Corrosives: Materials that can chemically damage skin, other materials, or transport equipment.
-
Class 9 — Miscellaneous Hazardous Materials: Materials presenting transportation hazards that do not fit within Classes 1–8.
How Many Hazard Classes for Fully Regulated Items vs. Partially Regulated Items?
There are still nine DOT hazard classes. Fully regulated and partially regulated items do not belong to separate classification systems.
Fully regulated shipments generally must comply with applicable Hazardous Materials Regulations, including requirements for packaging, marking, labeling, documentation, and placarding when required.
Some materials or quantities may qualify for specific exceptions or reduced requirements, depending on the material, packaging, quantity, and transportation conditions. The term partially regulated is informal, so shippers should check the exact regulation and applicable exceptions before shipping.
What Is in Each of the DOT Hazard Classes?
The nine DOT hazard classes group materials according to their primary transportation risks.
-
Class 1 — Explosives: Materials or articles that present an explosive hazard.
-
Class 2 — Gases: Regulated gases, including flammable, non-flammable, and toxic gases.
-
Class 3 — Flammable Liquids: Liquids that can ignite under specified conditions.
-
Class 4 — Flammable Solids: Flammable solids, certain self-reactive materials, and materials that may become dangerous when wet.
-
Class 5 — Oxidizers and Organic Peroxides: Substances that can intensify combustion or present related hazards.
-
Class 6 — Toxic and Infectious Substances: Materials that may cause poisoning or transmit infection.
-
Class 7 — Radioactive Materials: Materials that emit ionizing radiation and are regulated for transport.
-
Class 8 — Corrosives: Materials that can cause chemical damage to living tissue or other materials.
-
Class 9 — Miscellaneous Hazardous Materials: Materials that present regulated transportation hazards not covered by the other eight classes.
A material’s exact classification depends on its properties and the applicable DOT rules. Always verify the specific substance and shipping conditions instead of relying only on a general example.
DOT HazMat Training
Employees who perform functions covered by DOT hazardous materials regulations may need training appropriate to their job duties. Depending on the role, this can include general awareness, function-specific, safety, and security-awareness training.
OSHA 10-hour and 30-hour courses do not replace DOT HazMat training requirements. These programs address different training needs.
For broader workplace safety training, explore our OSHA 30-Hour Course or browse our workplace safety training resources.
Frequently Asked Questions
1. How many hazard classes are there for fully regulated items?
DOT recognizes nine primary hazard classes. Fully regulated status affects which shipping requirements apply; it does not create a separate set of hazard classes.
2. Are there nine or more than nine DOT hazard classes?
There are nine main classes, but some are divided into smaller divisions. This allows DOT to distinguish between more specific types of hazards.
3. Does OSHA 30 training qualify as DOT HazMat training?
No. OSHA 30 and DOT HazMat training address different requirements. Employees who perform covered hazardous-materials functions need training appropriate to their DOT duties.
Need Help Choosing Safety Training?
Understanding hazard classifications is an important step toward shipping hazardous materials safely and meeting applicable requirements. Review the training options available on our website, or contact our training team with questions.