A Hazardous Material is a substance or material which has been determined by the U.S. Secretary of Transportation to be capable of posing an unreasonable risk to health, safety, and property when transported in commerce and which has been so designated.

Title 49, U.S. Code of Federal Regulations (CFR) Transportation, Parts 100-199, govern hazardous materials transport.


Any chemical compound, mixture, or device the primary or common purpose of which is to function by explosion, e.g., with substantially instantaneous release of gas or heat, unless such compound, mixture, or device is otherwise specifically classified in Parts 170-189 of Title 49, U.S. Code of Federal Regulations (CFR) Transportation.



Detonating or otherwise of maximum hazard.


In general, these function by rapid combustion rather than detonation and include some explosive devices such as special fireworks, flash powders, etc. A flammable hazard.


Certain types of manufactured articles containing Class A or Class B explosives, or both, as components but in restricted quantities, and certain types of fireworks. Minimum hazard.


Any liquid having a flash point at or above 100° F and below 200° F under the conditions specified in Title 49, CFR.


Any liquid or solid that causes destruction of human skin tissue or a liquid that has a severe corrosion rate on steel.


Any liquid having a flash point below 100° F under the condition specified in Title 49


Any liquid which may ignite spontaneously when exposed to air the temperature of which is 55° C (130° F) or below.


Any material or mixture having in the container a pressure exceeding 40 psia at 70° F or 104 psia at 130° F.


Any compressed gas meeting the requirements for lower flammability limit, flammability limit range, flame projection, or flame propagation criteria.


Any compressed gas other than a flammable compressed gas.


Any solid material, other than explosive which is liable to cause fires through friction, absorption of moisture, spontaneous chemical changes, retained heat from manufacturing or processing, or which can be ignited readily and when ignited burns so vigorously and persistently as to create a serious transportation hazard.


An organic compound containing the bivalent -0-0- structure and which may be considered a derivative of hydrogen peroxide where one or more of the hydrogen atoms have been replaced by organic radicals must be classed as an organic peroxide.


A substance such as chlorate, permanganate, inorganic peroxide, nitro carbo nitrate, or a nitrate, that yields oxygen readily to stimulate the combustion of organic matter.


Extremely dangerous poisonous gases or liquids of such nature that a very small amount, mixed with air, is dangerous to life.


Less dangerous poisons. Substances, liquids or solids (including pastes and semi-solids) other than Class A or irritating materials which are known to be so toxic to man as to afford a hazard to health during transportation, or which, in the absence of adequate data on human toxicity, are presumed to be toxic to man based on results with test animals.


Liquid or solid substances, which, upon contact with fire or when exposed to air, give off dangerous or intensely irritating fumes, but not including any poisonous material, Class A.


An etiologic agent means a viable micro-organism, or its toxin, which causes or may cause human disease (Sec. 173.386 Refer to the Department of Health, Education and Welfare Regulations, Title 42, CFR).


Any material or combination or materials, that spontaneously emits ionizing radiation and has a specific activity greater than 0.002 microcuries per gram.

ORM-A, B or C (Other Regulated Materials)

Any material that does not meet the definition of a hazardous material, other than combustible liquid in packagings having a capacity of 110 gallons or less, and is specified in Sec. 172.101 as an ORM material or that possesses one or more of the characteristics described in ORM-A through D below (Sec. 173.500) NOTE: an ORM with a flash point of 100 F to 200 F, when transported with more than 110 gallons in one container shall be classed as a combustible liquid.


A material which has an anesthetic, irritating, noxious, toxic or other similar property and which can cause extreme annoyance or discomfort to passengers and crew in the event of leakage during transportation.


A material (including a solid when wet with water) capable of causing significant damage to a transport vehicle or vessel from leakage during transportation. Materials meeting one or both of the following criteria are ORM-B materials:

1.        A liquid substance that has corrosion rate exceeding 0.250 inch per year (IPY) on aluminum (nonclad 7075-T6) at a test temperature of 130° F. An acceptable test is described in NACE Standard TM-01-69.

2.        Specifically designated by name in Sec. 172.101 of the subchapter.


A material which has other inherent characteristics not described as an ORM-A or ORM-B but which makes it unsuitable for shipment, unless properly identified and prepared for transportation. Each ORM-C material is specifically named in Sec. 172.101 of the subchapter.


A material such as a consumer commodity which, though otherwise subject to the regulations of the subchapter, presents a limited hazard during transportation due to its form, quantity and packaging. They must be materials for which exceptions are provided in Sec. 72.101 of the subchapter. A shipping description applicable to each ORM-D material or category of ORM-D materials is found in Sec. 172.101 of the subchapter.


When transported internationally by air, hazardous materials may be classified as Dangerous Goods, according to the International Civil Aviation Organization (ICAO) Technical Instructions for the Safe Transport of Dangerous Goods by Air and the International Air Transport Association (IATA) Dangerous Goods Regulation.