CDL HazMat Endorsement key terms

The regulatory list in 49 CFR 172.101 that names hazardous materials and gives each one its proper shipping name, hazard class, identification number, packing group, label codes, and special provisions. Entries are ordered alphabetically by proper shipping name.

The exact name from the Hazardous Materials Table that must appear on shipping papers and package markings for a material. It is not a brand name or a casual description; using the wrong name can misinform emergency responders.

A four-digit number, usually preceded by UN or NA, that identifies a hazardous material in the Hazardous Materials Table. It appears on shipping papers, package markings, orange panels, and placards so responders can identify the material quickly.

One of nine regulatory categories that group materials by the type of risk they present, such as flammable liquid, corrosive, or radioactive. The class number and name appear on shipping papers and drive labeling and placarding decisions.

A subdivision within a hazard class that narrows the risk, such as Division 6.1 for toxic materials or Division 2.3 for toxic gases. Division numbers carry their own label and placard requirements and can change loading rules.

A Roman numeral (I, II, or III) assigned to many hazardous materials to show the degree of danger, with I being the greatest. It affects packaging requirements, quantity limits, and sometimes placarding thresholds.

The amount of a hazardous substance that, if released, must be reported to the National Response Center. When a shipment contains an RQ, the letters RQ must appear on the shipping paper before or after the basic description.

A material listed in Appendix A to 49 CFR 172.101 that is regulated because of its environmental risk when released. Shipments at or above the reportable quantity require the RQ notation on shipping papers.

A material that harms aquatic life when released into water, as designated under the hazardous materials regulations. It may require the words Marine Pollutant on the shipping paper even when the material is not otherwise regulated as a hazardous substance.

A material that is regulated as waste and meets hazardous characteristics or is listed by EPA. Hazardous waste shipments need a manifest and often use the words Hazardous Waste on shipping papers instead of a basic description in the usual order.

The paperwork that accompanies a hazardous materials shipment and describes what is being carried. It must be legible, in English, kept within reach of the driver, and readily available to emergency responders during an incident.

The required sequence on a shipping paper: proper shipping name, hazard class or division, identification number, and packing group. The order matters, and the description must be easy to find without searching through unrelated freight entries.

Information that tells responders and drivers how to handle a spill, fire, or exposure involving the material being carried. It must accompany the shipping paper and may be a guidebook page, a telephone number, or a written response plan.

A reference organized by guide number that gives initial isolation distances, protective actions, and firefighting guidance for hazardous materials incidents. It is commonly used by drivers and responders before more detailed information arrives.

A multi-copy tracking form required for hazardous waste shipments that records the generator, transporter, and receiving facility. Every party signs it, and the driver must keep a copy with the shipment until it is delivered.

Required information placed directly on a package or cargo tank, such as the proper shipping name, identification number, or orientation arrows. Markings are durable, legible, and distinct from labels, which communicate the hazard class.

A diamond-shaped warning placed on a package that shows the hazard class or division of the contents, such as flammable liquid or corrosive. Labels are smaller than placards and apply to individual packages rather than the whole vehicle.

A large, diamond-shaped warning sign attached to the outside of a vehicle, trailer, or bulk container to warn the public and responders of the hazard being carried. Placards show the hazard class and may show the identification number.

The quantity of a hazardous material above which placards are required, commonly 1,001 pounds aggregate gross weight for many materials. Some hazards, such as certain toxic or radioactive materials, require placards at any quantity.

The combined weight of all packages of a material plus their packaging, used when deciding whether placards are required. It is totaled across the load rather than judged package by package.

A placard used for loads that require more than one hazard placard, or for certain mixed loads, to give a general warning instead of showing each hazard. It does not replace required identification numbers or shipping paper details.

The principle that hazardous materials may be loaded together only if their hazards do not create an added risk, such as a fire hazard or a violent reaction. Incompatible materials must be separated or carried on separate vehicles.

The required physical separation of incompatible hazardous materials during loading, such as keeping oxidizers away from flammables. Separation may mean distance, barriers, or different compartments, depending on the materials involved.

Methods used to keep cargo from shifting during transport, such as dunnage, load bars, or inflatable bags. Secure cargo protects containers from damage that could cause a release of hazardous contents.

The system of tiedowns, straps, and structural restraints that keeps a load from moving on the vehicle. For hazardous materials, securement also protects packages and tanks from impact damage that could cause leaks.

The process of placing hazardous materials on a vehicle, including checking compatibility, securing packages, and confirming labels and placards. Loading errors are a common cause of releases and roadside violations.

Removing hazardous materials from a vehicle, with attention to containment, grounding, and avoiding spills. The driver must confirm the receiving site is authorized and that packages are not dropped or damaged during removal.

Connecting a tank or container to a ground source so static electricity cannot spark during transfer of flammable liquids. Bonding connects containers to each other; grounding connects them to the earth.

A liquid with a low flash point that can give off vapors igniting easily at normal temperatures. Placards, shipping paper entries, and loading rules for these materials focus on vapor control and ignition sources.

The lowest temperature at which a liquid gives off enough vapor to ignite when a flame is applied. It is a key property used to classify flammable and combustible liquids and to set handling precautions.

A rule requiring that a vehicle carrying certain hazardous materials be parked away from bridges, tunnels, buildings, and crowded places, and attended or secured unless the material is nonflammable and noncorrosive. Some materials require constant attendance.

A parked vehicle that someone is physically present with, awake and able to move it if needed. Certain hazardous loads require attendance while parked, and unattended vehicles must be locked and secured against movement.

The required or preferred path a hazardous materials vehicle takes, which may avoid tunnels, congested areas, or restricted roads. Local and state rules can require specific routes for certain classes, such as explosives.

A rule that prohibits or limits hazardous materials vehicles in certain tunnels because a release inside would be especially dangerous. Signs at tunnel entrances identify the restrictions, and drivers must plan alternate routes.

The distance responders keep people away from a hazardous materials release, often set by the Emergency Response Guidebook. Initial isolation may be increased based on fire, wind, or container damage.

The practice of noticing and reporting suspicious behavior, tampering, or unauthorized access around hazardous materials shipments. Drivers are expected to keep loads secured, limit information sharing, and report threats to their employer or authorities.

Required instruction for anyone who handles, loads, or drives hazardous materials, covering general awareness, function-specific duties, safety, and security. Training must be documented and repeated periodically, and the driver must carry proof of it.