Virginia CDL HazMat key terms

Any substance or material that the U.S. Department of Transportation has determined can pose an unreasonable risk to health, safety, or property when transported in commerce, and that is regulated under the hazmat rules.

One of nine broad categories used to group hazardous materials by the type of danger they present, such as explosives, gases, flammable liquids, oxidizers, and corrosives.

The amount of a hazardous substance that, if released, must be reported to federal authorities; specific quantities for each substance are listed in the appendix to the hazardous materials table.

A person who directly affects hazardous materials transportation safety, for example by loading, unloading, handling, packaging, or driving a vehicle carrying hazmat, and who must be trained and tested.

The company or person that prepares a hazardous material shipment and offers it for transport; the shipper is responsible for classifying, packaging, marking, labeling, and documenting the material.

Written or printed information that must accompany a hazmat shipment, describing the material's hazards, protective actions, and first aid so responders can act quickly during a release.

The transport document, such as a bill of lading or manifest, that describes the hazardous materials in a shipment and must travel with the load.

The required order of information on a shipping paper for each hazardous material: UN identification number, proper shipping name, hazard class or division, and packing group.

A four-digit number preceded by the letters UN or NA that identifies a specific hazardous material, such as UN1203 for gasoline, and appears on shipping papers and packages.

The name of a hazardous material exactly as listed in the DOT Hazardous Materials Table, which must be used on shipping papers, package markings, and labels.

A Roman numeral I, II, or III assigned to a hazardous material that shows its degree of danger, with I representing the greatest hazard and III the least.

A diamond-shaped warning notice placed on a hazardous materials package that shows the hazard class of the contents and warns handlers and responders.

A larger diamond-shaped warning sign mounted on the outside of a vehicle or bulk package that identifies the hazard class of its contents; required when quantities exceed regulatory thresholds.

Required letters, numbers, or symbols on a package, such as the proper shipping name, UN number, or orientation arrows, that identify the contents and how to handle them.

The master list in the hazmat regulations that gives the proper shipping name, hazard class, packing group, label codes, and special provisions for each regulated material.

Keeping incompatible hazardous materials apart during loading and transport so they cannot react dangerously if they leak or mix, following the segregation table.

The quality of hazardous materials that can be loaded and carried together without a dangerous reaction; incompatible materials must be separated or kept off the same vehicle.

Using dunnage, bars, air bags, or other devices to stop packages from shifting, sliding, or falling during transport, which protects the packaging and the vehicle.

A packaging other than a vessel or barge that holds hazardous material without intermediate containment and has a capacity greater than 119 gallons for liquids or 882 pounds for solids.

A bulk packaging permanently attached to a motor vehicle that is used to carry liquid or gaseous hazardous materials and is built to specific DOT design and testing standards.

A motor vehicle that carries a cargo tank or portable tank; driving one requires a tanker endorsement, and carrying hazmat in it also requires the hazmat endorsement.

The empty space deliberately left in a cargo tank above the liquid so the product can expand as it warms, preventing overflow or a ruptured tank.

The shifting and forward rush of liquid inside a partially filled tank during braking or turning, which can push the vehicle and cause loss of control.

An internal wall or partition inside a cargo tank that divides the liquid into sections, reducing surge and helping the driver keep the vehicle stable.

A rule that limits where hazmat vehicles may travel, such as designated hazmat routes, tunnel bans, or city street prohibitions, which the driver must plan around.

Requirements for where a hazmat vehicle may be parked, generally away from crowds, buildings, and other vehicles, and only left unattended when properly secured.

The requirement that a driver stay with or close to a hazmat vehicle while it is parked or being loaded, unless it is secured in a safe location.

A DOT publication, organized by guide numbers, that helps drivers and emergency responders identify hazards and take initial protective actions for materials involved in a release.

A hazmat release or accident that meets DOT reporting criteria, such as a death, injury, evacuation, or a release of a reportable quantity, and must be reported and documented.

The federal operations center that must be called immediately when a reportable quantity of hazardous material is released during transportation, so agencies can respond.

Training that teaches drivers to notice and report possible threats, such as suspicious people, tampering with a vehicle, or unusual questions about a hazmat load.

A written plan required for certain high-risk hazmat shipments that covers personnel security, facility security, and en-route security measures.

Required instruction covering general awareness, function-specific duties, safety, and security, which must be completed and documented before an employee performs hazmat work.

A CDL endorsement (H) that allows a driver to operate a commercial vehicle carrying hazardous materials, after passing a knowledge test and a TSA threat assessment.

A background check by the Transportation Security Administration that decides whether a hazmat endorsement applicant poses a security threat and may hold the endorsement.

A CDL endorsement (N) required to drive a vehicle with a cargo tank of 1,000 gallons or more, often held together with the hazmat endorsement for bulk hazmat hauling.

A criminal conviction or security finding, such as a terrorism-related crime or certain felonies, that prevents a person from holding a hazmat endorsement.