This glossary presents definitions of certain terms used in this section. A complete glossary of terms can be found in the federal Hazardous Materials Rules (49 CFR 171.8). You should have an up-to-date copy of these rules for your reference.
NOTE: You will not be tested by us or DDS on this glossary. It’s just here for reference only.
Bulk packaging – Packaging, other than a vessel, or a barge, including a transport vehicle or freight container, in which hazardous materials are loaded with no intermediate form of containment and which has:
- A maximum capacity greater than 450 L (119 gallons) as a receptacle for a liquid;
- A maximum net mass greater than 400 kg (882 pounds) or a maximum capacity greater than 450 L (119 gallons) as a receptacle for a solid; or
- A water capacity greater than 454 kg (1000 pounds) as a receptacle for a gas as defined in Sec. 173.115.
Cargo tank – A bulk packaging which:
- Is a tank intended primarily for the carriage of liquids or gases and includes appurtenances, reinforcements, fittings, and closures (for “tank”, see 49 CFR 178.345-1(c), 178.337-1, or 178.338-1, as applicable);
- Is permanently attached to or forms a part of a motor vehicle, or is not permanently attached to a motor vehicle but which, by reason of its size, construction, or attachment to a motor vehicle is loaded or unloaded without being removed from the motor vehicle; and
- Is not fabricated under a specification for cylinders, portable tanks, tank cars, or multi unit tank car tanks.
Carrier — A person engaged in the transportation of passengers or property by:
- Land or water as a common, contract, or private carrier, or
- Civil aircraft
Consignee – The business or person to whom a shipment is delivered.
Division – A subdivision of a hazard class.
EPA – U.S. Environmental Protection Agency.
FMCSR – The Federal Motor Carrier Safety Regulations.
Freight container– a reusable container having a volume of 64 cubic feet or more, designed and constructed to permit being lifted with its contents intact and intended primarily for containment of packages (in unit form) during transportation.
Fuel tank — A tank, other than a cargo tank, used to transport flammable or combustible liquid or compressed gas for the purpose of supplying fuel for propulsion of the transport vehicle to which it is attached, or for the operation of other equipment on the transport vehicle.
Gross weight or gross mass – The weight of the packaging plus the weight of its contents.
Hazard class — The category of hazard assigned to a hazardous material under the definitional criteria of Part 173 and the provisions of the Sec. 172.101 Table. A material may meet the defining criteria for more than one hazard class but is assigned to only one hazard class.
Hazardous materials – A substance or material which has been determined by the 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. The term includes hazardous substances, hazardous wastes, marine pollutants, elevated temperature materials and materials designated as hazardous in the hazardous materials table of §172.101, and materials that meet the defining criteria for hazard classes and divisions in §173, subchapter c of this chapter.
Hazardous substance – A material, including its mixtures and solutions, that:
1. Is listed in Appendix A to Sec. 172.101;
2. Is in a quantity, in one package, which equals or exceeds the reportable quantity (RQ) listed in Appendix A to Sec. 172.101; and
3. When in a mixture or solution
» For radionuclides, conforms to paragraph 7 of Appendix A to Sec. 172.101.
» For other than radionuclides, is in a concentration by weight which equals or exceeds the concentration corresponding to the RQ of the material, as shown in Figure 9.12.
This definition does not apply to petroleum products that are lubricants or fuels (see 40 CFR 300.6).
Hazardous waste – For the purposes of this chapter, means any material that is subject to the Hazardous Waste Manifest Requirements of the U.S. Environmental Protection Agency specified in 40 CFR Part 262.
Intermediate bulk container (IBC) — A rigid or flexible portable packaging, other than a cylinder or portable tank, which is designed for mechanical handling. Standards for IBCs manufactured in the United States are set forth in subparts N and O §178.
Limited quantity — The maximum amount of a hazardous material for which there may be specific labeling or packaging exception.
Marking – The descriptive name, identification number, instructions, cautions, weight, specification, or UN marks or combinations thereof, required by this subchapter on outer packaging of hazardous materials.
Mixture – A material composed of more than one chemical compound or element.
Name of contents – The proper shipping name as specified in Sec. 172.101.
Non-bulk packaging – A packaging, which has:
1. A maximum capacity of 450 L (119 gallons) as a receptacle for a liquid;
2. A maximum net mass less than 400 kg (882 pounds) and a maximum capacity of 450 L (119 gallons) or less as a receptacle for a solid; or
3. A water capacity greater than 454 kg (1,000 pounds) or less as a receptacle for a gas as defined in Sec. 173.115.
N.O.S. – Not otherwise specified.
Outage or ullage – The amount by which a packaging falls short of being liquid full, usually expressed in percent by volume.
Portable tank – Bulk packaging (except a cylinder having a water capacity of 1,000 pounds or less) designed primarily to be loaded onto, or on, or temporarily attached to a transport vehicle or ship and equipped with skids, mountings, or accessories to facilitate handling of the tank by mechanical means. It does not include a cargo tank, tank car, multi unit tank car tank, or trailer carrying 3AX, 3AAX, or 3T cylinders.
Proper shipping name – The name of the hazardous materials shown in Roman print (not italics) in Sec. 172.101.
P.s.i. or psi – Pounds per square inch.
P.s.i.a. or psia — Pounds per square inch absolute.
Reportable quantity (RQ) – The quantity specified in Column 2 of the Appendix to Sec. 172.101 for any material identified in Column 1 of the Appendix.
RSPA — now PHMSA — The Pipeline and Hazardous Materials Safety Administration, U.S. Department of Transportation, Washington, DC 20590.
Shipper’s certification – A statement on a shipping paper, signed by the shipper, saying he/she prepared the shipment properly according to law. For example:
“This is to certify that the above named materials are properly classified, described, packaged, marked and labeled, and are in proper condition for transportation according to the applicable regulations or the Department of Transportation.” or
“I hereby declare that the contents of this consignment are fully and accurately described above by the proper shipping name and are classified, packaged, marked and labeled/ placarded, and are in all respects in proper condition for transport by * according to applicable international and national government regulations.”
* words may be inserted here to indicate mode of transportation (rail, aircraft, motor vehicle, vessel)
Shipping paper – A shipping order, bill of lading, manifest, or other shipping document serving a similar purpose and containing the information required by Sec. 172.202, 172.203, and 172.204.
Technical name – A recognized chemical name or microbiological name currently used in scientific and technical handbooks, journals, and texts.
Transport vehicle – A cargo-carrying vehicle such as an automobile, van, tractor, truck, semitrailer, tank car, or rail car used for the transportation of cargo by any mode. Each cargo carrying body (trailer, rail car, etc.) is a separate transport vehicle.
UN standard packaging — A specification packaging conforming to the standards in the UN recommendations.
UN – United Nations
Here is another expansive, but not exhaustive list of hazmat terms. Some of these may be repeated of the above entries.
- Hazardous Material (Hazmat): A substance that poses a risk to health, safety, property, or the environment when transported or handled.
- DOT: Department of Transportation – The U.S. federal agency responsible for regulating hazmat transportation.
- UN Number: United Nations number – A four-digit identifier assigned to hazardous substances for international transport.
- MSDS: Material Safety Data Sheet – A document containing information about hazards, handling, storage, and emergency response for hazardous materials.
- NFPA: National Fire Protection Association – Develops codes and standards for fire safety, including hazmat.
- GHS: Globally Harmonized System – An international framework for hazard communication.
- Placard: A label affixed to vehicles carrying hazardous materials indicating the nature of the hazard.
- Class 1: Explosives – Materials that can explode due to heat, shock, or friction.
- Class 2: Gases – Flammable, non-flammable, or toxic gases.
- Class 3: Flammable Liquids – Liquids with low flash points that can ignite.
- Class 4: Flammable Solids – Solids that can catch fire under certain conditions.
- Class 5: Oxidizing Substances – Materials that provide oxygen, enhancing combustion.
- Class 6: Toxic Substances – Substances that can cause harm when inhaled, ingested, or absorbed.
- Class 7: Radioactive Materials – Materials that emit ionizing radiation.
- Class 8: Corrosive Substances – Substances that can cause damage to living tissue or materials.
- Class 9: Miscellaneous Hazardous Materials – Materials that don’t fit into other classes but still pose risks.
- RQ: Reportable Quantity – The minimum amount of a hazardous substance that must be reported if released.
- EPA: Environmental Protection Agency – U.S. agency responsible for environmental regulation.
- Emergency Response Guidebook: A manual providing guidance on hazmat identification and emergency response.
- Secondary Containment: Backup systems to prevent hazmat spills from spreading.
- ADR: European Agreement Concerning the International Carriage of Dangerous Goods by Road.
- IATA: International Air Transport Association – Regulates aviation transportation of hazmat.
- IMDG: International Maritime Dangerous Goods – Guidelines for sea transport of hazardous materials.
- Bulk Packaging: Containers used for transporting large quantities of hazardous materials.
- MSFC: Maximum Safe Filling Capacity – The maximum amount of material a container can hold.
- Compliance: Adherence to hazmat regulations and standards.
- Dike: A barrier to contain spills.
- Flash Point: The lowest temperature at which a substance produces flammable vapors.
- Gauge Pressure: Pressure measured above atmospheric pressure.
- Hazardous Waste: Waste that poses a substantial threat to health, safety, or the environment.
- Ignitable: Materials that can easily catch fire.
- Jettison: To intentionally discard cargo to reduce risks.
- Kilogram (kg): A unit of mass commonly used for measuring hazardous materials.
- Label: Information affixed to packages indicating hazards and required actions.
- Marine Pollutant: A substance harmful to aquatic environments.
- N.O.S.: Not Otherwise Specified – Used for classifying mixtures of hazardous materials.
- Oxidizer: A substance that provides oxygen, promoting combustion.
- PPE: Personal Protective Equipment – Gear worn to protect against hazards.
- Quantities Exempted: Small quantities of hazardous materials exempt from certain regulations.
- Radioactive Yellow-II Label: A label for packages containing radioactive materials.
- Spill Kit: A set of tools used to contain and clean up spills.
- Toxic Inhalation Hazard (TIH): A hazardous material that, when inhaled, can cause serious health issues.
- UN Performance Packaging: Packaging meeting specific UN standards for hazardous materials.
- Vapor Density: The ratio of the density of a gas or vapor to the density of air.
- Waste Manifest: A document tracking the movement of hazardous waste.
- Xylene: A flammable, aromatic hydrocarbon used in various applications.
- Yield Strength: The point at which a material deforms permanently.
- Z Number: A placard indicating a hazmat vehicle contains bulk explosives.
- Adhesion: The tendency of a substance to bond to a surface.
- Boiling Point: The temperature at which a liquid turns into a vapor.
- Chemical Compatibility: The ability of substances to coexist without reacting dangerously.
- Detonation: A rapid, explosive combustion reaction.
- Explosive Range: The range of concentrations where a flammable gas can ignite.
- Fire Point: The temperature at which a liquid produces enough vapor to support combustion.
- Gas Cylinder: A container for compressed gases.
- Hazard Zone: An area affected by a hazardous material release.
- Infectious Substance: A substance containing pathogens.
- Jet Fuel: A flammable liquid used in aviation.
- Kerosene: A hydrocarbon liquid used as a fuel.
- Lithium Battery: A rechargeable battery containing lithium as a power source.
- Molarity: Concentration of a solute in a solution.
- Non-Bulk Packaging: Packaging for smaller quantities of hazardous materials.
- Overpack: An additional packaging used to contain multiple packages.
- Placard Holder: A frame used to display placards on a vehicle.
- Quantity Limitations: Maximum amounts of hazardous materials that can be transported.
- Radiation: Energy emitted as electromagnetic waves or particles.
- Shipping Name: The name used to identify a hazardous material for transportation.
- Tank Container: A specialized container for transporting liquids or gases.
- Ullage: The unfilled space in a container.
- Viscosity: A fluid’s resistance to flow.
- Weathering: The process of hazardous materials breaking down due to exposure to environmental factors.
- X-Ray: Electromagnetic radiation used for imaging.
- Yield Stress: The point at which a material undergoes deformation.
- Zoning: Designating areas for hazardous materials storage and transportation.
- Asphyxiant: A gas that displaces oxygen, causing suffocation.
- Barricade: A barrier used to control access to hazardous areas.
- Carcinogen: A substance known to cause cancer.
- Dermal: Relating to the skin.
- Erosion: The wearing away of materials due to external factors.
- Flammable Range: The range of concentrations in which a substance can ignite.
- Groundwater: Water that collects beneath the Earth’s surface.
- Hazard Class: The classification of hazardous materials based on their characteristics.
- Inhalation Hazard: A hazard posed when a substance is inhaled.
- Junction: A point where roads or tracks meet.
- Kinetic Energy: Energy due to motion.
- Labelmaster: A leading provider of regulatory compliance solutions for hazardous materials.
- Molecule: A group of atoms bonded together.
- Noxious: Harmful or poisonous.
- Oxidation: A chemical reaction involving the loss of electrons.
- Pressure Relief Valve: A safety device that releases pressure from a container.
- Quenching: Rapid cooling to harden materials.
- Residue: Material remaining after a process.
- Solvent: A liquid used to dissolve other substances.
- Tank Car: A railcar designed to transport liquids or gases.
- UV (Ultraviolet) Light: Electromagnetic radiation with a shorter wavelength than visible light.
- Vapor Pressure: The pressure exerted by a vapor in equilibrium with its liquid.
- Water Reactive: A substance that reacts with water to produce a hazardous reaction.
- Xenon: A colorless, odorless gas used in lighting.
- Yellow Placard: A label indicating the presence of a radioactive material.
- Zinc: A metallic element used in various applications.
- Absorption: The process of one substance being taken into another.
- Backdraft: A violent fire caused by the sudden introduction of oxygen.
- Cylinder Valve: A valve controlling the release of gases from a cylinder.
- Dangerous When Wet: A classification for substances that can react violently with water.
- EPA Identification Number: A code assigned to hazardous waste generators.
- Flammable Liquid: A liquid with a flash point below 100°F (37.8°C).
- Gloves: Personal protective equipment for hand protection.
- HAZWOPER: Hazardous Waste Operations and Emergency Response – OSHA regulations for hazmat response.
- Incident Command System (ICS): A standardized approach to incident management.
- Jettisoning: Discarding cargo to reduce risks.
- Kilopascal (kPa): A unit of pressure commonly used in hazmat calculations.
- Liquefied Gas: A gas that has been cooled and compressed to a liquid state.
- Microorganism: A microscopic organism, often harmful.
- Nanotechnology: The manipulation of materials at the nanometer scale.
- Organic Peroxide: A hazardous material that can initiate combustion.
- Packing Group: A classification indicating the level of hazard presented by hazardous materials.
- Quick Response Guide (QRG): A condensed guide for responding to hazmat incidents.
- Radiation Monitoring: Monitoring levels of ionizing radiation.
- Secondary Hazard: A hazard caused by exposure to another hazard.
- Toxicity: The degree to which a substance can cause harm to living organisms.
