UN Model Regulations on the Transport of Dangerous Goods


The UN Model Regulations cover all aspects of transportation necessary to provide international uniformity. They include a comprehensive criteria based classification system for substances that pose a significant hazard in transportation. Hazards addressed include explosiveness, flammability, toxicity (oral, dermal and inhalation), corrosivity to human tissue and metal, reactivity (e.g., oxidizing materials, self reactive materials, pyrophoric substances, substances that react with water), radioactivity, infectious substance hazards and environmental hazards. They prescribe standards for packagings and multimodal tanks used to transport hazardous materials. They also include a system of communicating the hazards of substances in transport through hazard communication requirements which cover labeling and marking of packages, placarding of tanks, freight containers and vehicles, and documentation and emergency response information that is required to accompany each shipment.

Based on a proposal from the United States the UN Model Regulations were reformatted in the form of a Model Regulation. Many national, regional and modal regulations governing the transport of dangerous goods are now based on the UN Recommendations, some of the regulations were structured differently requiring consignors of dangerous goods to be familiar with the unique structure of all applicable regulations. The lack of structural harmony of regulations can frustrate compliance and to the extent that it results in noncompliance is detrimental to safety. Furthermore, a Model Regulation can easily be adopted in National legislations of countries throughout the world eliminating the need for countries to reissue the regulations in the format of their national regulations.

In the past, the process of incorporating amendments to the UN Recommendations was resource intensive. In the case of international organizations, each change to the Recommendations was reevaluated before being introduced into the various international regulations. In some cases the amendments had to be reproposed by governments participating in these meetings. The fact that each of these issues was rediscussed, reworded and reorganized by each of the affected regulatory bodies increased the likelihood for disharmony. The Model Regulation is serving to reduce the necessity for the majority of these efforts and in turn is enhancing harmonization.

About the Sub-Committee

The Transport of Dangerous Goods Sub-Committee (TDG Sub-Committee) provides leadership in internationally harmonizing regulations on the transportation of hazardous materials (dangerous goods) by developing an internationally agreed regulatory framework set out in the United Nations Recommendations on the Transport of Dangerous Goods (UN Model Regulations). The UN Recommendations form the basis for international modal regulations on the transport of dangerous goods prepared by the International Maritime Organization (IMO) and the International Civil Aviation Organization (ICAO). The UN Model Regulations are also used as a basis for the development of regional (e.g., NAFTA and European Road and Rail regulations) and national transport regulations, including the U.S. Hazardous Materials Regulations.

Participants in the TDG Sub-Committee include 27 countries with voting status and numerous countries and non-governmental organizations with observer status. The TDG Sub-Committee is responsible for reviewing proposals from voting member countries and observers in relation to amendments to the UN Recommendations and issues relevant to its work program. The TDG Sub-Committee meets four times in a two year period (biennium). PHMSA represents the United States at these meetings and formulates U.S. positions based on feedback from U.S. industry, the public and other government agencies.

The work of the Committee has become increasingly important to both international and domestic transportation of hazardous materials to, from and within the United States. Virtually all hazardous materials imported to or exported from the United States are transported in accordance with international regulations based on the UN Recommendations. In the case of the U.S., the decisions of the TDG Sub-Committee affect an international trade volume in hazardous materials with an estimated dollar value of $160 (based on 2003 data) billion annually. Domestically the US Chemical industry accounted for shipments of chemicals valued at approximately $466.4 billion in 2003. In addition to enhancing safe transportation through improved regulatory consistency, international harmonization of hazardous materials regulations plays a significant role in maintaining a U.S. favorable balance of trade in chemicals. The work of the TDG Sub-Committee also affects a much larger domestic hazardous materials transportation volume.

PHMSA is interested in comments on proposals submitted to the TDG Sub-Committee and will consider comments in formulating formal U.S. positions on UN proposals. Comments should be sent in writing to Duane Pfund at duane.pfund@dot.gov or Shane Kelley at shane.kelley@dot.gov. Copies of TDG Sub-Committee documents may be downloaded from the UN Transport Secretariat's website.

Participants and Voting

The following countries have expert status and as such are able to vote on proposals under consideration by the Subcommittee of Experts on the Transport of Dangerous Goods (TDG Subcommittee): Argentina, Australia, Austria, Belgium, Brazil, Canada, China, Czech Republic, Finland, France, Germany, India, Islamic Republic of Iran, Italy, Japan, Mexico, Morocco, Netherlands, Norway, Poland, Portugal, Russian Federation, South Africa, Spain, Sweden, the United Kingdom of Great Britain and Northern Ireland and the United States of America

Refer to the link at the right for a list of TDG Sub-Committee participants.

Sub-Committee Plans during 2013-2014

The United Nations Transport of Dangerous Goods Sub-Committee (TDG Sub-Committee) will meet four times during the 2013-2014 biennium and plans to address a number of issues. PHMSA encourages the public to participate in the work of the TDG Sub-Committee and to comment on the work items. Comments may be provided to Mr. Duane Pfund at (202) 366-0656 or by email at duane.pfund@dot.gov.

The primary topics which the TDG Sub-Committee plans to address during the 2013-2014 biennium include:

  • Explosives and related matters (including amendments to the list of dangerous goods; desensitized explosives; tests and criteria for flash compositions; review of test series 6; review of tests in parts I and II of the Manual of Tests and Criteria; review of packing instructions for explosives)
  • Listing, classification and packing (including amendments to the list of dangerous goods; classification of polymerizing substances; classification of substances listed by name in the dangerous goods list which do not meet the classification criteria or which meet criteria for hazards not identified in the list)
  • Electric storage systems (including testing of lithium batteries, safety procedures for damaged/defective lithium batteries not covered by current regulatory text; transport of large batteries; thermal batteries)
  • Transport of gases (including transport of ethylene oxide and propylene oxide mixtures; global recognition of UN and non-UN pressure receptacles; composite cylinders)
  • Miscellaneous proposals of amendments to the UN Model Regulations (including fuels in machinery or equipment; articles containing small quantities of dangerous goods; used medical devices; transport of environmentally hazardous substances; terminology issues; marking and labeling issues; packaging issues; tank issues; scope of section 5.5.3)
  • Electronic data interchange
  • Cooperation with IAEA (including transport of radioactive material possessing additional hazards)
  • Global harmonization of transport of dangerous goods regulations with the UN Model Regulations
  • Guiding principles for the Model Regulations (updating, including rationale for assignment of E codes)
  • Issues relating to the GHS (including corrosivity criteria; criteria for water-reactivity; classification criteria and flammability categories for certain refrigerants; classification and testing of oxidizing solids; expert judgment/weight of evidence.