The U.S. Department of Transportation and the United Nations classify dangerous goods into nine hazard classes, each representing a different type of risk during transport. Knowing your cargo’s class is the first step to legal, safe shipping — it determines packaging, labeling, placarding, documentation, and which carriers can even accept the load. Here is a clear breakdown of all nine hazmat classes.
The nine hazardous materials classes
Class 1 – Explosives
Materials that can detonate or rapidly combust, such as fireworks, ammunition, and blasting agents. Divided into six divisions by sensitivity and blast effect.
Class 2 – Gases
Compressed, liquefied, or dissolved gases, split into flammable gases (2.1), non-flammable/non-toxic gases (2.2), and toxic gases (2.3). Propane and aerosols are common examples.
Class 3 – Flammable Liquids
Liquids with a low flash point — gasoline, paint, alcohol, and many solvents. One of the most frequently shipped hazmat classes.
Class 4 – Flammable Solids
Covers flammable solids (4.1), spontaneously combustible materials (4.2), and substances dangerous when wet (4.3), like certain metal powders and matches.
Class 5 – Oxidizers and Organic Peroxides
Oxidizers (5.1) intensify fires by releasing oxygen; organic peroxides (5.2) are thermally unstable. Examples include ammonium nitrate and some pool chemicals.
Class 6 – Toxic and Infectious Substances
Poisons (6.1) and infectious substances (6.2) such as pesticides and certain medical materials.
Class 7 – Radioactive Materials
Any material emitting ionizing radiation, from medical isotopes to industrial sources, with strict packaging and transport index rules.
Class 8 – Corrosives
Substances that damage skin, metal, or other materials on contact — sulfuric acid, sodium hydroxide, and many batteries.
Class 9 – Miscellaneous Dangerous Goods
Hazards that don’t fit the other classes, including lithium batteries, dry ice, and environmentally hazardous substances.
Why correct classification matters
Every hazmat class carries its own packaging standards, hazard labels, vehicle placards, and entries on the bill of lading. Misclassifying a shipment can mean rejected freight, DOT fines, or — far worse — a dangerous incident in transit. Drivers hauling hazmat need a hazardous materials endorsement, and carriers need the proper registration and security plans.
Shipping hazmat through Miami
Hazardous freight demands carriers with the right certifications and trained personnel. Go Freight is an asset-based Miami 3PL operating as a TSA-approved bonded carrier with 100+ owned trucks and our own chassis pool — built to move regulated cargo compliantly across South Florida and beyond. Because we are asset-based with no double brokering, you always know exactly who is handling your dangerous goods. See our dedicated hazmat logistics services.
Frequently asked questions
Who decides a material’s hazmat class?
The shipper is responsible for correctly classifying goods using the DOT Hazardous Materials Table and the chemical’s safety data sheet (SDS). When unsure, consult a hazmat specialist or your carrier.
Are lithium batteries hazmat?
Yes. Lithium batteries fall under Class 9 and have specific packaging, marking, and quantity rules that change frequently — always check current regulations before shipping.
Do I need special carriers for hazmat?
Yes. Hazmat requires carriers with proper DOT registration, trained and endorsed drivers, and the right placards and documentation. Not every trucking company can legally haul every class.
Move regulated freight with confidence
Go Freight’s TSA-approved bonded operation handles hazmat the right way. Request a free quote or call (786) 445-0150.