There are nine hazard classes for fully regulated items under the U.S. Department of Transportation's Hazardous Materials Regulations (HMR).

These classes cover materials posing significant risks during transport, ensuring proper labeling, packaging, and handling to prevent accidents. Fully regulated items follow all HMR rules, unlike limited quantities with exceptions.

Core Hazard Classes

Here's a breakdown of the nine classes, with everyday examples for clarity:

Class| Description| Example
---|---|---
1| Explosives| Fireworks 1
2| Gases (flammable, non-flammable, toxic)| Propane cylinders 1
3| Flammable liquids (flash point <140°F)| Paint thinner 1
4| Flammable solids; spontaneously combustible; dangerous when wet| Magnesium shavings 1
5| Oxidizers and organic peroxides| Pool chlorine 1
6| Toxic and infectious substances| Pesticides 1
7| Radioactive materials| Medical isotopes 1
8| Corrosives| Battery acid 3
9| Miscellaneous dangerous goods| Lithium batteries 3

This table draws from standard DOT guidelines, where Class 9 catches unique hazards not fitting elsewhere.

Why Nine Classes Matter

Knowing these prevents mishaps—like shipping sanitizer as a flammable liquid (Class 3) in approved containers. New hires often tape this list dockside for quick checks, turning compliance into habit. SDS sheets reveal the class via flash points or toxicity data.

In practice, always classify first: "Does it explode? Oxidize? Corrode?" This guides labels before loading. Carriers and regulators accept training built around these nine.

Quick Training Tips

  • Quiz yourself: Match propane to Class 2.2 (non-flammable gas).
  • Real-world story: A dock worker once mislabeled chlorine (Class 5), sparking a delay—lesson learned via printable checklists.
  • Updates as of 2026: No changes to the nine-class structure; lithium batteries stay under Class 9A.

TL;DR: Nine classes keep shipments safe—explosives to miscellany.

Information gathered from public forums or data available on the internet and portrayed here.