The Hazardous Materials Table (HMT) is found in 49 CFR 172.101.

The HMT is central to the hazardous materials regulations. It provides a reference to hazmat entries identified by proper shipping name and the associated UN ID number. The HMT also references the authorized packaging, appropriate hazard class labels, and any special provisions or quantity limitations for all hazmat entries.

First, a brief explanation of the columns in the table:

• Column 1, Symbols. The symbols are described in 172.101(b) and indicate if there are restrictions or exceptions applicable to the material.
• Column 2, Hazardous materials descriptions and proper shipping names. Proper shipping names are limited to those shown in Roman type (not italics).
• Column 3, Hazard class or Division. Column 3 contains a designation of the hazard class or division corresponding to each proper shipping name, or the word “Forbidden”.
• Column 4, Identification Numbers. Column 4 lists the identification number assigned to each proper shipping name. Those preceded by the letters “UN” are associated with proper shipping names considered appropriate for international transportation as well as domestic transportation. Those preceded by the letters “NA” are associated with proper shipping names not recognized for transportation outside of the United States.
• Column 5, PG or Packing Group. The packing group indicate the degree of danger the material presents. PG I is great danger, PG II is medium danger, and PG III is minor danger.
• Column 6, Label Codes. This column provides the appropriate hazard warning label(s) required on the package (unless exempt or otherwise specified in the regulations).
• Column 7, Special provisions. Special provisions contain packaging provisions, prohibitions, exceptions from requirements for particular quantities or forms of materials, and requirements or prohibitions applicable to specific modes of transportation.
• Column 8, Packaging. Column 8 is broken down into three sub-columns:
  • Column 8A, Exceptions. Column 8A contains exceptions from some of the requirements of the HMR;
  • Column 8B, Non-bulk. Column 8B prescribes packaging requirements for non-bulk packagings; and
  • Column 8C, Bulk. Column 8C prescribes packaging requirements for bulk packagings, subject to the limitations, requirements, and additional authorizations of Columns 7 and 8B.
• Column 9, Quantity limitations. Column 9 is broken down into two columns. Columns 9A and 9B specify the maximum quantities that may be offered for transportation in one package by passenger-carrying aircraft or passenger-carrying rail car (Column 9A) or by cargo aircraft only (Column 9B).
• Column 10, Vessel stowage requirements. Column 10 is broken down into two columns. Column 10A specifies the authorized stowage locations on board cargo and passenger vessels. Column 10B specifies codes for stowage and handling requirements for specific hazardous materials.

Reference 172.101(b) - (k) for complete column descriptions.

How to use the table:

1. Find the material in the HMT by the:

• Proper shipping name (Column 2)
• Identification number (Column 4)

• Also check:

• Appendix A to § 172.101, List of Hazardous Substances and Reportable Quantities. A hazardous material is a hazardous substance if the material is listed in Appendix A to 172.101, concentration limits are exceeded, and the amount in one package equals or exceeds the reportable quantity (RQ). Check the footnotes to Appendix A as they may affect the proper shipping name selection.
• Appendix B to § 172.101, List of Marine Pollutants. A hazardous material is also a marine pollutant if the material is listed in Appendix B to 172.101, and when in a solution or mixture, the concentration by weight equals or exceeds 10 percent for materials listed in Appendix B, or 1 percent for material identified as a “severe marine pollutant” in Appendix B. Marine pollutant requirements and exceptions apply to marine pollutants transported by vessel and do not apply to non-bulk shipments by rail, air, or highway.

2. Check the symbols in Column 1. This table provides a brief explanation of the symbols (see regulation for complete details):

4. Refer to Column 5 and Column 8 (8A, 8B, and 8C) for information on packaging, packaging exceptions, and provisions for non-bulk and bulk packages.

5. Refer to Column 6 for details on the required labels (and be sure to also check 172.300 for marking requirements and 172.500 for placarding requirements).

6. If shipping by air or rail, refer to Column 9 as needed. If shipping by water, check Column 10.