Hazardous materials (hazmat) are substances or articles that pose a risk to health, safety, property, or the environment during transport. Regulatory agencies — including the U.S. Department of Transportation (DOT), the International Air Transport Association (IATA), and the International Maritime Organization (IMO) — define hazardous materials classifications and impose strict requirements for packaging, labeling, documentation, and carrier handling.
Hazardous Materials Classifications
The DOT classifies hazardous materials into nine classes:
- Class 1: Explosives
- Class 2: Gases (flammable, non-flammable, toxic)
- Class 3: Flammable and combustible liquids
- Class 4: Flammable solids, spontaneously combustible materials, and materials dangerous when wet
- Class 5: Oxidizers and organic peroxides
- Class 6: Toxic and infectious substances
- Class 7: Radioactive materials
- Class 8: Corrosives
- Class 9: Miscellaneous hazardous materials (includes lithium batteries, dry ice, magnetized materials)
Hazmat Shipping Requirements
Shipping hazardous materials requires: proper UN-specification packaging tested and certified for the specific hazard class, standardized labeling and placarding, a shipper’s declaration (for air) or hazardous materials shipping paper (for ground), and in many cases, trained and certified shipping personnel. Carriers charge hazardous materials surcharges — typically $40-$70 or more per package for parcel carriers.
Lithium Batteries as Hazmat
One of the most commonly misunderstood hazmat categories for e-commerce shippers is lithium batteries. Standalone lithium-ion or lithium metal batteries — and many products containing them (laptops, power tools, e-bikes) — are classified as Class 9 hazardous materials. Air shipments of lithium battery products are subject to IATA regulations with strict quantity limits, packaging requirements, and declaration obligations.