Mississippi CDL HazMat Endorsement Test key terms

Any substance or material that the Secretary of Transportation determines can pose an unreasonable risk to health, safety, or property when transported in commerce. This includes materials meeting the definitions in 49 CFR 171.8.

One of nine broad categories (e.g., explosives, gases, flammable liquids) used to classify hazardous materials based on their dominant risk. Each class may have divisions with more specific criteria.

A subdivision within a hazard class that further specifies the degree of risk (e.g., Division 2.1 flammable gas, Division 6.1 toxic). Divisions are identified by a number after the class number.

A special authorization added to a commercial driver's license (CDL) that permits the driver to operate a vehicle transporting hazardous materials requiring placards. It requires a knowledge test and a TSA security threat assessment.

A background check conducted by the Transportation Security Administration to determine whether an applicant for a hazmat endorsement poses a security threat. It involves fingerprinting and checks against terrorist watchlists and criminal records.

A document such as a bill of lading, manifest, or dangerous goods declaration that describes a hazardous material shipment. It must include the basic description, emergency response information, and a shipper's certification.

The minimum information required on a shipping paper for a hazardous material: the proper shipping name, hazard class or division, UN identification number, and packing group (if applicable), in that sequence.

A four-digit number preceded by 'UN' that uniquely identifies a hazardous material for international and domestic transport (e.g., UN1203 for gasoline). It must appear on shipping papers and certain packages.

A diamond-shaped warning sign affixed to a vehicle or bulk package to indicate the hazard class of its contents. Placards must be displayed for certain quantities and materials as specified in 49 CFR Part 172 Subpart F.

The quantity of a hazardous material that triggers placarding requirements, generally 1,001 pounds aggregate gross weight for most materials, or any quantity for certain high-risk materials like Division 2.3 or 6.1 PG I.

Information that must accompany a hazardous material shipment to aid emergency responders, such as a emergency response guidebook page, telephone number, or safety data sheet. It must be immediately available during transport.

A reference book published by DOT that provides guidance for first responders to hazardous material incidents. It includes numbered guides for each hazard class and lists of materials with their UN numbers.

A hazardous material that is toxic when inhaled and poses a severe risk in the event of a release. TIH materials are in Division 2.3 (gas) or Division 6.1 (liquid/solid) Packing Group I and require special handling and routing.

A bulk packaging permanently attached to a vehicle, used for transporting liquid or gaseous hazardous materials. Cargo tanks must meet specific design and inspection requirements in 49 CFR Part 180.

A bulk packaging that is not permanently attached to a vehicle and can be loaded or unloaded without being emptied. It must meet design and certification standards, often marked with a UN symbol and specification plate.

A packaging, other than a vessel or barge, with a capacity greater than 119 gallons for liquids, 882 pounds for solids, or 1,000 pounds for gases. Bulk packagings include cargo tanks, portable tanks, and totes.

The separation of incompatible hazardous materials during loading and storage to prevent dangerous reactions. Segregation requirements are found in the segregation table in 49 CFR 177.848.

The use of tiedowns, blocking, or other means to prevent hazardous materials from shifting or falling during transport. Specific requirements are in 49 CFR 393 and must be followed for all loads.

The requirement that a qualified person remain with a vehicle transporting certain hazardous materials (e.g., Division 2.3, 6.1 PG I) when parked, unless the vehicle is secured in a designated area. Attendance rules are in 49 CFR 397.5.

Regulations specifying where and how a vehicle carrying hazardous materials may be parked. Generally, parking must be off the roadway, away from populated areas, and the vehicle must be attended or secured as required.

The selection of roads and highways for transporting hazardous materials. Certain materials (e.g., TIH, explosives) may be required to use designated routes, and drivers must follow local or state restrictions.

A prohibition or limitation on the transport of certain hazardous materials through tunnels. Drivers must obey signs and may need to use alternate routes for materials like flammable gases or explosives.

An intersection where a road crosses railroad tracks. Vehicles carrying hazardous materials must stop before crossing, check for trains, and proceed only when safe, unless exempted by a flagger or signal.

Regulations governing fueling of vehicles carrying hazardous materials. The engine must be turned off during fueling, and fueling is prohibited in certain areas or while the vehicle is attended by unauthorized persons.

The requirement to report certain hazardous material incidents (e.g., spills, leaks, fires) to the National Response Center and other authorities. Reporting must be immediate and include details of the material and release.

The training and vigilance required of hazmat drivers to recognize and report suspicious activity, secure their vehicles, and prevent unauthorized access to hazardous materials. It is part of required hazmat training.

The loss of eligibility to hold a hazmat endorsement or drive a commercial vehicle due to criminal convictions, security threat assessment results, or other violations. Disqualifications are specified in 49 CFR Part 383 and TSA rules.

Required instruction for hazmat employees on regulations, safe handling, emergency response, and security awareness. Training must be provided initially and every three years, with a certificate of completion.

The application of required information on a package or vehicle, such as the proper shipping name, UN number, or orientation arrows. Markings are distinct from labels and placards.

A warning sign affixed to a hazardous material package (not a vehicle) that indicates the hazard class of the contents. Labels are smaller than placards and are required for non-bulk packages.

A grouping of hazardous materials within a hazard class that indicates the degree of danger: I (great danger), II (moderate danger), or III (minor danger). Packing groups affect packaging and placarding requirements.

A hazardous material in Class 1 that can rapidly release energy through chemical reaction, causing fire, blast, or fragmentation. Explosives are divided into six divisions (1.1 to 1.6) based on their behavior.

A liquid with a flash point of not more than 60°C (140°F) that can easily ignite. Class 3 flammable liquids are common hazardous materials and require specific packaging, placarding, and handling.

A substance in Class 5.1 that can cause or enhance combustion of other materials by yielding oxygen. Oxidizers can react violently with organic materials and require segregation from flammables.

A material in Class 7 that emits ionizing radiation above a certain threshold. Transport requires special packaging, labeling, and route controls to protect people and the environment.

A material in Class 8 that causes visible destruction or irreversible damage to skin or steel. Corrosives include strong acids and bases and require careful handling and segregation.

A material in Class 9 that presents a hazard during transport but does not fit into another class. Examples include lithium batteries and environmentally hazardous substances.

The proper name of a hazardous material as listed in the Hazardous Materials Table (49 CFR 172.101). It must be used on shipping papers and package markings; generic or trade names are not acceptable.