The 10 Columns of the Hazmat Table, Explained

A column-by-column breakdown of 49 CFR §172.101 — what each of the ten columns in the Hazardous Materials Table actually tells you.

Column 1 — Symbols

A small set of letters and a plus sign that change how the rest of the row applies. The most common ones: A means the material is only regulated when offered for transport by aircraft; W means the material is only regulated by vessel; D means the proper shipping name is used for domestic transport only, not international; G means a technical name must be added in parentheses; I marks entries specific to the IMDG Code (ocean shipping). A plus sign (+) fixes the hazard class and packing group for that entry even if the material would otherwise test into a different class.

Column 2 — Hazardous materials descriptions and proper shipping names

The exact, legally required name for the material on shipping papers and package markings. This is not necessarily the common or trade name — it's the specific regulatory name, and it has to match what's printed in this column precisely (with limited allowed variations, like adding a technical name in parentheses when required by a Column 1 "G" symbol).

Column 3 — Hazard class or division

One of the nine hazard classes (or a numbered division within a class, like 2.1 or 4.3), or the word "Forbidden" if the material cannot be offered for transportation under any circumstances. This is the single most consequential column — it drives which labels, placards, and packaging rules apply.

Column 4 — Identification numbers

The four-digit UN or NA number that identifies the specific material for shipping purposes, used on shipping papers, packages, and placards.

Column 5 — Packing group (PG)

A Roman numeral (I, II, or III) showing how severe the hazard is within its class — I is the most dangerous, III the least. Not every hazard class uses a packing group; explosives, gases, and radioactive materials are handled differently.

Column 6 — Label codes

Which diamond-shaped hazard labels have to go on the package. A material can require more than one label if it has a subsidiary hazard in addition to its primary class.

Column 7 — Special provisions (§172.102)

Numbered or lettered codes pointing to extra requirements that don't fit anywhere else in the table — exceptions, additional marking rules, quantity limits specific to that material, or restrictions on certain packaging types. These codes are easy to skip past, but they can override what the rest of the row seems to say.

Column 8 — Packaging (§173.***)

Three sub-columns citing the exact sections of 49 CFR Part 173 that authorize packaging for that material: Exceptions (when you can skip the normal packaging rules entirely, usually for small quantities), Non-bulk packaging, and Bulk packaging.

Column 9 — Quantity limitations

Two sub-columns: how much of the material is allowed on a passenger aircraft or passenger rail car, and separately, how much is allowed on a cargo-only aircraft. Many materials that are forbidden or tightly limited for passenger transport have a higher limit — or no limit — on cargo aircraft.

Column 10 — Vessel stowage

Two sub-columns: a location code (A, B, C, D, or E) showing where on a vessel the material must be stowed, and an "other" column with additional stowage requirements — keeping it away from certain other cargo, requiring specific deck placement, and similar rules.

Reading a full row

Put together, a single row answers: what is this material called (2), how dangerous and in what way (3), what number identifies it (4), how severe within its class (5), what labels go on it (6), what special rules apply (7), how must it be packaged (8), how much can go by air (9), and how must it be stowed on a ship (10). Column 1's symbols modify how several of the others apply. That's the complete shipping picture for one material — and it's exactly what a HazmatTable search returns without you having to parse the raw table yourself.

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