5.3 The Hazardous Materials Table: Columns 1 through 5

5.3 The Hazardous Materials Table: Columns 1 through 5

The Hazardous Materials Table (HMT) codified in Title 49 CFR § 172.101 is the foundational regulatory directory for commercial hazardous materials transportation in the United States. It is the master reference through which shippers classify commodities and through which motor carriers and commercial drivers determine legal shipping descriptions, package labeling, vehicle placarding, and packaging integrity.

Every commercial driver preparing for the Virginia CDL HazMat endorsement exam must know how to interpret all ten columns of the table and recognize the operational implications of each entry.

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The 10 Columns of the Hazardous Materials Table

+--------+------------------------------------+-------+--------+-----+--------+------------+--------------------+---------------------+----------------+
| Col 1  | Col 2                              | Col 3 | Col 4  | Col | Col 6  | Col 7      | Col 8: Packaging   | Col 9: Quantity     | Col 10: Vessel |
| Sym    | Proper Shipping Name               | Class | ID No. | 5   | Labels | Special    | Authorizations     | Limitations         | Stowage        |
|        |                                    |       |        | PG  |        | Provisions | (8A / 8B / 8C)     | (9A / 9B)           | (10A / 10B)    |
+--------+------------------------------------+-------+--------+-----+--------+------------+--------------------+---------------------+----------------+

Column 1: Symbols

Column 1 contains six regulatory symbols that modify or restrict the application of the row entry:

• + (Plus Sign): Fixes the proper shipping name, hazard class, and packing group listed in that row without regard to the actual hazard characteristics of the material. The material must be offered and transported under that entry even if physical testing suggests a different hazard classification.
• A: Identifies materials that are subject to the Hazardous Materials Regulations only when offered or transported by aircraft (unless the material is a hazardous substance or hazardous waste).
• D: Identifies proper shipping names approved for domestic transportation within the United States. These names may not be accepted in international commerce or cross-border maritime/air shipping.
• G: Identifies generic or n.o.s. (not otherwise specified) proper shipping names. Whenever symbol G appears, 49 CFR § 172.203(k) mandates that the recognized technical chemical name of the hazardous material must appear in parentheses immediately following the proper shipping name on shipping papers and package markings (e.g., Flammable liquids, n.o.s. (contains Ethanol, Acetone)).
• I: Identifies proper shipping names preferred for international transportation. These names are recognized by the International Maritime Dangerous Goods (IMDG) Code and the International Civil Aviation Organization (ICAO) Technical Instructions.
• W: Identifies materials that are subject to hazardous materials regulation only when offered or transported by vessel (unless the material is an EPA hazardous substance or hazardous waste).

Column 2: Hazardous Materials Descriptions and Proper Shipping Names

Column 2 establishes the official proper shipping name that must appear on bills of lading, hazardous waste manifests, and non-bulk package markings.

• Roman vs. Italicized Type: Only words printed in roman (regular, non-italicized) type form the official proper shipping name. Words printed in italics are explanatory, optional, or restrictive and cannot be used as the proper shipping name. For example, in Paint, corrosive, liquid, only the word "Paint" in roman type is the official shipping name unless the entry is printed entirely in roman text.
• Punctuation and Modifiers: Where an entry appears as Acid, hydrochloric, the words may be transposed to read Hydrochloric acid on shipping papers. Qualifying terms like liquid or solid may be omitted if the physical state is obvious from the container context.

Column 3: Hazard Class or Division

Column 3 provides the primary numerical hazard class or division (e.g., 3, 2.1, 8, 5.1).

• If an entry reads Forbidden, 49 CFR § 173.21 prohibits offering or transporting that material under any circumstances on a commercial motor vehicle.
• Entries marked Combustible liquid indicate liquids with flash points between 140°F and 200°F.

Column 4: Identification Numbers

Column 4 assigns the four-digit identification code displayed on diamond placards, orange panels, or white square-on-point markings:

• UN (United Nations): Identifiers authorized for both international and domestic commerce across all modes of transportation.
• NA (North American): Identifiers issued by DOT PHMSA and Transport Canada, authorized exclusively for domestic transportation within the United States and Canada. NA numbers are not recognized for overseas international marine or air transportation.
• ID: Used specifically for consumer commodities transported by air (e.g., ID8000).

Column 5: Packing Group

Column 5 lists the Roman numeral (I, II, or III) denoting the degree of danger. If no packing group is assigned (as with Class 2 gases, Class 7 radioactive materials, and Class 1 explosives), this column remains blank.