Free CDL Hazardous Materials Practice Test 2026
Study hazard communication, shipping papers, placards, loading rules, parking, and emergency response responsibilities. Knowledge tests are federal: you need 80% on each one (49 CFR 383.135(a)(1)), whether you test in Texas, California, or anywhere else. QuizLane has 71 reviewed hazardous materials questions with explanations.
- Hazard classes
- Placards and labels
- Shipping papers
- Loading and segregation
Sample questions
5 hazardous materials practice questions
Each sample shows the correct answer with a plain-language explanation. The full 71-question bank is in the practice run after you pick a state.
1. Hazard Class 1 covers:
- AFlammable liquids
- BRadioactive materials
- CCorrosives
- Explosives
Answer: Explosives. Class 1 includes explosives such as dynamite, fireworks, and ammunition (with many divisions and restrictions).
2. Hazardous-material placards are used mainly to:
- AShow vehicle ownership
- BReplace shipping papers
- CAdvertise the carrier
- Communicate a material's hazard class
Answer: Communicate a material's hazard class. Placards warn the public and emergency responders about the general type of hazard. They do not replace required documentation.
3. Never load corrosive liquids with certain incompatible explosives, poisonous gases, or:
- AEmpty packaging only
- BORM-D consumer commodities always
- CClass 9 miscellaneous only
- Division 4.2 spontaneously combustible materials and specified poison divisions
Answer: Division 4.2 spontaneously combustible materials and specified poison divisions. Segregation tables forbid many corrosive/explosive/poison combinations because mixing can cause fires or toxic releases.
4. The only acceptable way to check tire pressure on a placarded hazmat vehicle is:
- AListening for tone when tapped
- BKicking the tire
- Using a tire pressure gauge
- DVisual estimate from the cab
Answer: Using a tire pressure gauge. Check each tire at the start of the trip and each time you park. Do not drive on a flat except to the nearest safe repair point.
5. A four-digit identification number preceded by UN or NA is used mainly to:
- ASet the speed limit
- BReplace placards entirely
- CShow the carrier’s USDOT number
- Help first responders identify the material (often via the ERG)
Answer: Help first responders identify the material (often via the ERG). ID numbers appear on shipping papers and often on placards or orange panels for bulk packages.
Common questions
Before you start this CDL practice test
Other CDL knowledge tests
Keep going topic by topic.
- General knowledge
- Air brakes
- Combination vehicles
- Tank vehicles
- Doubles & triples
- Passenger vehicles
- School bus
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