The hazmat ("H") endorsement lets a CDL holder legally transport placarded quantities of hazardous materials. Getting it takes a written knowledge test plus a TSA background check. This page covers what the test actually asks, the facts worth knowing cold, and a set of practice questions to check yourself against.
The purpose of the Hazardous Materials Regulations and the roles of shippers, carriers, and drivers.
Shipping papers, package marking, labeling, and placarding — how a load is identified from the paperwork to the outside of the vehicle.
Segregation rules, blocking and bracing, and materials that can't be loaded together.
Marking, loading, and unloading rules specific to cargo tanks and other bulk containers.
Recognizing security risks, controlling access to your load, and following your carrier's security plan.
What documentation must be in the vehicle and what to do — and not do — if there's an incident.
State CDL manuals vary slightly in wording, but these core facts are consistent nationally because they come from the federal Hazardous Materials Regulations (49 CFR Parts 171–180).
Tap a question to reveal the answer and a short explanation.
Not within 25 feet. The 25-foot no-smoking rule applies to placarded cargo tanks used for Class 3 and Division 2.1 materials, and to placarded cargo compartments carrying Divisions 1.1, 1.2, 1.3, 4.2, 4.3, or Class 5 materials.
Within immediate reach, clearly visible to anyone entering the cab. If you leave the vehicle, they must be left on the driver's seat or in a pouch on the driver's door — never locked away out of sight.
Quantity thresholds. Table 1 materials require placards regardless of amount. Table 2 materials only require placards once the aggregate gross weight of all Table 2 hazmat on the vehicle reaches 1,001 lbs (454 kg).
Do not transport it. A driver may not transport a package known to be leaking, damaged, or otherwise non-compliant. Isolate it and report it per your carrier's procedure instead of continuing the trip.
Personnel security, unauthorized access, and en route security — required for carriers transporting hazmat quantities that require placarding, so a load isn't left accessible to anyone who shouldn't have it.
No. Certain hazard class combinations are prohibited or restricted under the segregation rules — for example, some explosives can't be loaded with certain oxidizers or flammable materials. Always check the segregation table before mixed loads.
A TSA Security Threat Assessment — a background check that includes fingerprinting. Both the test and the background check must be completed and passed.
Passing the endorsement test is the start — day to day, the piece drivers actually reach for is fast placard and UN number identification. HazMat Pro's Quiz Mode drills placard, UN number, and glossary recall the way it's tested, and the app doubles as an offline field reference once you're endorsed and hauling.
Placard and UN number recall practice, plus a full offline reference for placards, UN numbers, ERG guide numbers, and GHS terminology.
Open HazMat ProThe "H" endorsement on a CDL, required to legally transport placarded quantities of hazardous materials. It requires a written knowledge test and a TSA background check.
Why the regulations exist, shipping papers and placarding, loading/unloading and segregation, bulk packaging, security awareness, and emergency response information.
Yes — a TSA Security Threat Assessment, including fingerprinting, in addition to the knowledge test.
No. It's an independent field reference and training aid, not affiliated with FMCSA, TSA, or any state DMV. Its Quiz Mode covers the placard/UN number/glossary identification piece — pair it with your state's official CDL manual for the full curriculum.
Placards, UN numbers, ERG guide numbers, and Identify — offline.
Search 100+ UN numbers for class, packing group, and ERG guide.
Type a UN number or material, get the guide number.
All 9 hazard classes, UN numbers, and ERG guide numbers explained.