Pennsylvania CDL HazMat key terms

Any substance or material capable of posing an unreasonable risk to health, safety, or property when transported in commerce, as listed in the Hazardous Materials Table or meeting a defined hazard class.

The regulatory listing in 49 CFR 172.101 that names each regulated material and specifies its hazard class, identification number, packing group, required labels, and packaging exceptions.

One of nine categories defining the type of danger a material presents, such as explosives, flammable liquids, oxidizers, toxic substances, or radioactive material, each with its own rules.

A subdivision within a hazard class that narrows the hazard, such as Class 1 explosives split into divisions 1.1 through 1.6 or Class 2 gases split into 2.1, 2.2, and 2.3.

A rating of I, II, or III assigned to a material showing its degree of danger, where I is great danger, II is moderate danger, and III is minor danger.

The required sequence on a shipping paper giving the identification number, proper shipping name, hazard class or division, and packing group, in that order, for each hazardous material.

The name of a hazardous material exactly as it appears in the Hazardous Materials Table, which must be used on shipping papers and package markings instead of a brand or common name.

A four-digit number, sometimes preceded by UN or NA, that identifies a hazardous material and appears on shipping papers, package markings, and orange placards.

Written guidance that must accompany hazardous materials shipping papers, describing immediate hazards, firefighting and spill response, and first aid so responders can act before arriving.

The transport document, such as a bill of lading or manifest, that describes hazardous materials in the required basic description and must be kept within reach of the driver while driving.

A reference book, commonly called the ERG, that organizes hazardous materials by guide number and gives initial isolation distances, protective actions, and first aid for responders.

A diamond-shaped warning sign, at least 10.75 inches square, attached to a vehicle or bulk package to show the hazard class of the contents being transported.

The chart in 49 CFR 172.504 that specifies which hazard classes and quantities require placards on a vehicle, including the 1,001-pound aggregate rule for Table 2 materials.

The combined weight of all hazardous materials in a vehicle that fall under Placard Table 2, used to decide when the 1,001-pound placarding threshold is reached.

A smaller diamond-shaped warning sticker, about 4 inches on each side, placed on a non-bulk package to show the hazard class of the material inside it.

Required information printed or attached directly on a package, such as the proper shipping name, identification number, orientation arrows, or the word OVERPACK, that communicates contents and handling needs.

An enclosure such as a box or crate used to consolidate one or more packages for handling, which must itself be marked with the word OVERPACK and the required markings of the inner packages.

A package with a capacity of 119 gallons or less for liquids, or a net mass of 882 pounds or less for solids, that generally requires labels rather than placards.

A package with a capacity greater than 119 gallons for liquids, more than 882 pounds net mass for solids, or more than 1,000 pounds water capacity for gases.

A tank permanently attached to a motor vehicle, or forming part of the vehicle frame, used to carry liquid or gaseous hazardous materials in bulk.

A bulk container that is not permanently attached to a vehicle, is designed to be lifted on and off, and must meet specific design and test requirements for the materials it carries.

The required separation of incompatible hazardous materials, or of hazardous materials from food and animal feed, during loading and transport to prevent dangerous reactions or contamination.

The use of tiedowns, blocking, bracing, or shoring to keep packages and containers from shifting, sliding, or falling during transport, as required for all cargo including hazardous materials.

A letter designation A through S, excluding I, that groups explosives by chemical similarity so that only compatible groups may be loaded together without special approval.

A material, often a gas or volatile liquid, that is toxic when inhaled and requires special handling, inhalation hazard markings, and specific loading and parking precautions.

A letter A through D assigned to poison inhalation hazards indicating the severity of the inhalation risk, with Zone A being the most dangerous and requiring the strictest controls.

The radius, given in the Emergency Response Guidebook, within which people should be kept away from a spill or fire involving a hazardous material during the initial response.

Material that spontaneously emits ionizing radiation above defined limits, requiring special shipping papers, labels, placards, and secure loading rules, including exclusive-use shipment options.

A shipment arrangement where a single shipper uses an entire vehicle or container, allowing certain relaxed rules but requiring the vehicle to be dedicated to that load until delivery.

A material that is discarded or intended to be discarded and meets hazardous waste criteria, requiring a uniform hazardous waste manifest and specific shipping paper notations.

A multi-copy tracking form that follows a hazardous waste shipment from generator through transporter to the disposal facility, documenting each handoff and final receipt.

The amount of a hazardous substance released that triggers immediate notification to the National Response Center, typically one pound unless the material has a different listed quantity.

The federal clearinghouse that must be notified immediately, by telephone, when a hazardous material release meets or exceeds a reportable quantity during transportation.

The written report required after certain hazardous materials events, such as a release, fire, or injury, submitted to the responsible federal agency within the specified time after the event.

Packaging that must pass standardized tests, such as drop, stacking, and pressure tests, for the packing group and material it will hold, rather than meeting a prescribed design.

A parked hazardous materials vehicle that remains within the driver's view and control, a requirement for parking certain loads unless the vehicle is properly secured and unattended rules apply.

Restrictions on where a hazardous materials vehicle may be left, including distance from bridges, tunnels, buildings, and places of public assembly, and when the engine may be left running.

A prohibition on smoking or carrying open flames near vehicles carrying flammable, oxidizing, or explosive materials, including during loading, unloading, and while parked.