Hazardous materials transportation information table

What is the DOT Hazardous Materials Table?

The U.S. Department of Transportation (DOT) Hazardous Materials Table (HMT), located in 49 CFR 172.101, is the backbone of the federal Hazardous Materials Regulations (HMR) and the single most important reference tool for determining how hazardous materials must be classified, described, packaged, marked, labeled, and transported in commerce. Every shipper, carrier, and hazardous materials employee in the United States relies on this table to ensure compliance with the law. The table lists over 3,000 hazardous materials by name, providing critical information about each substance’s transportation requirements and hazards. Properly using this table is essential to prevent accidents, protect the public, and maintain regulatory compliance.

How to Use the DOT Hazardous Materials Table

Using the HMT correctly involves a step-by-step process. First, the shipper identifies the material by its technical or trade name, then locates its proper shipping name in the table. Next, the shipper notes the corresponding UN/NA identification number, hazard class, and packing group. These details are used to select the correct packaging specifications under Part 173, apply the appropriate markings and labels on containers, prepare shipping papers under 49 CFR 172.200–172.204, and determine whether placards are required on transport vehicles per Subpart F of Part 172. Every decision in the shipping process—from the type of container used to the documentation prepared—traces back to the information found in the Hazardous Materials Table.

The DOT Hazardous Materials Table

10 Columns

The HMT is structured into ten columns, each of which provides a specific regulatory requirement. Understanding how to read and apply these columns is key to shipping any hazardous material safely and legally.

The first column—known as the “Symbols” column— serves a very specific purpose: it provides quick visual indicators that tell the user whether a particular entry in the table has special regulatory significance or limitations. These symbols appear directly to the left of the UN/NA identification number and act as shorthand references to help shippers, carriers, and compliance personnel understand how the material is regulated. Each symbol has a distinct meaning that affects how the entry is used, interpreted, or applied under the HMR.

Here’s a detailed explanation of the symbols you may find in this column and what each represents:

(+) – Fixed classification; cannot be altered.
(A) – Regulated only by air.
(D) – Domestic entry only.
(I) – International entry.
(G) – Requires a technical name.
(W) – Regulated only by water.
(—) – No special symbol; standard regulation applies.

The second column contains the Proper Shipping Name (PSN)—the official name that must be used to describe the material on shipping papers, markings, and labels. This name must appear exactly as shown in the table, including any required modifiers such as “solution,” “mixture,” or “waste.” When a specific chemical name is not listed, shippers may be required to use a more general entry such as “Flammable liquids, n.o.s.” (“not otherwise specified”). Choosing the correct shipping name is crucial because it dictates nearly every other requirement for the shipment.

The third column shows the Hazard Class or Division assigned to the material. The DOT defines nine major hazard classes—ranging from Class 1 (explosives) to Class 9 (miscellaneous hazardous materials)—with further divisions to identify specific risks such as flammability, corrosivity, or toxicity. For example, Class 3 covers flammable liquids, while Class 6.1 covers toxic substances. This classification determines which hazard labels and placards must be displayed on the packages and vehicles.

The fourth column lists the Identification Number, which corresponds directly to the hazard class and shipping name and must appear on packages and shipping documents. The fifth column provides the Packing Group (PG), represented by Roman numerals I, II, or III, indicating the relative degree of danger—I for high hazard, II for medium hazard, and III for low hazard. The packing group determines how robust and tested a container must be; for instance, a PG I chemical must be packaged in stronger, more secure containers than a PG III substance.

The sixth column identifies any labels required for the package. Labels are the diamond-shaped hazard warnings affixed to containers, and the table tells the shipper exactly which ones are required (e.g., “Flammable Liquid,” “Corrosive,” “Toxic”). Some materials require multiple labels if they present more than one hazard—for example, a toxic, flammable gas would need both “Toxic Gas” and “Flammable Gas” labels.

The seventh column, labeled Special Provisions, contains numerical codes that refer to Section 172.102, where each code’s meaning is explained in detail. These provisions may grant packaging exceptions, specify special handling requirements, or restrict certain modes of transportation. For instance, a special provision might state that a material can only be shipped by cargo aircraft, or that it must not be loaded with certain incompatible materials.

The eighth column provides the Packaging Authorizations and is divided into three parts: (8A) Exceptions, (8B) Non-bulk Packaging, and (8C) Bulk Packaging. These subcolumns refer the user to specific sections in 49 CFR Part 173, which outline exactly how the material must be packaged. For example, (8B) might direct the shipper to “§173.202,” which describes approved container types, testing standards, and closure requirements for flammable liquids.

The ninth column specifies quantity limitations per package for each mode of transport—(9A) Passenger aircraft or rail and (9B) Cargo aircraft only. These restrictions ensure that certain high-risk materials are limited to small amounts on passenger planes or prohibited entirely from such transport. A notation of “Forbidden” in this column means the material may not be transported by that mode under any circumstance.

The tenth column, labeled Vessel Stowage, applies to maritime transportation. It tells shippers and carriers how the material must be stored aboard a vessel and whether it must be segregated from other materials that could react dangerously. Stowage codes like “A,” “B,” or “D” correspond to specific instructions found in 49 CFR Part 176, ensuring safe transport by water.

DOT HMT Appendices

Beyond these ten columns, the appendices to the HMT are equally vital. Appendix A lists hazardous substances and their Reportable Quantities (RQs), connecting DOT rules with EPA spill-reporting requirements under CERCLA. Appendix B lists marine pollutants that must be identified when transported by vessel. Together, these references ensure that both transportation and environmental regulations are met simultaneously.

Using the table correctly requires careful, methodical work. The process begins with identifying the material by its technical or trade name, locating the correct entry in the table, and noting its UN/NA number, hazard class, packing group, and special provisions. From there, the shipper determines the authorized packaging, markings, labels, and documentation required. For example, when shipping Acetone (UN1090), the table shows that it is a Class 3 flammable liquid, Packing Group II, and references §173.202 for packaging. This tells the shipper to use tested UN specification containers, mark the package with the proper shipping name and UN number, apply a flammable liquid label, and include a shipping paper entry reading: “UN1090, Acetone, 3, II.”

Regulatory Roadmap

The 49 CFR 172.101 HMT is not just a list—it is a regulatory roadmap. Every column leads to other sections of the HMR that provide detailed requirements for classification, packaging, and documentation. Understanding how to navigate the table ensures that hazardous materials are transported safely and legally across all modes—highway, rail, air, and sea. Improper use of the table can result in misclassification, improper packaging, or incorrect labeling, any of which can cause severe safety incidents and heavy penalties.

Summary

In summary, the DOT HMT serves as the central reference for all hazardous material transportation requirements under federal law. It connects a material’s identity to its hazard class, packaging standards, quantity limits, and labeling obligations. Mastery of the table is essential for every trained HAZMAT employee under 49 CFR 172.704, as it ensures compliance, protects the public, and upholds the integrity of the nation’s hazardous materials transportation system.