The hazmat endorsement test has 30 questions, and you need to answer at least 24 correctly to pass

The hazmat endorsement written test is administered by your state's Department of Motor Vehicles (DMV) or equivalent licensing authority. The test covers rules for transporting hazardous materials safely. You will see 30 multiple-choice questions on the actual exam, and passing requires a score of 80 percent — that means 24 correct answers out of 30.

The test is separate from your commercial driver's license (CDL) knowledge test. You take it after you pass the general CDL exam and any other endorsement tests you need. Some states allow you to take the hazmat test on the same day as your CDL test; others require you to schedule it separately. Check with your state DMV to confirm the process where you are testing.

Key Takeaways

  • The hazmat endorsement test contains 30 multiple-choice questions, and you must answer at least 24 correctly to pass.
  • Test content covers hazard classes, shipping papers, placarding, loading and unloading, and emergency procedures for hazardous material incidents.
  • You can retake the test if you do not pass, though your state may require you to wait a certain number of days between attempts.
  • The hazmat manual published by your state DMV is the primary study resource, and most states make it available free online.

What the hazmat test covers

The 30 questions draw from five main topic areas. You will encounter questions about hazard classes — the nine categories that organize hazardous materials by their danger type, such as explosives, flammable liquids, or toxic substances. Other questions test your knowledge of shipping papers, the documents that must accompany hazmat shipments and describe what is being transported.

Placarding and labeling make up another section. You need to know which placards go on vehicles carrying specific materials, where they go, and what they mean. The test also covers loading and unloading procedures — how to safely handle hazmat cargo, where it can be placed on a vehicle, and what precautions to take. Finally, you will see questions about emergency response: what to do if a hazmat shipment leaks, catches fire, or causes an accident.

The questions are not evenly distributed across these topics. Hazard classes and shipping papers typically account for the largest share of questions, while emergency procedures may appear less frequently. Your state's hazmat manual breaks down the topics and tells you which sections are most heavily tested.

How to prepare for the 30-question test

Your state DMV publishes a hazmat endorsement manual that covers everything on the test. This manual is your primary study resource and is usually free to read from your state's DMV website. Read through it carefully, paying special attention to the hazard classes, since those questions appear most often.

Many states also offer practice tests online, either through the DMV website or through third-party study sites. Practice tests let you see the format and style of questions you will face. Take several practice tests and review any questions you miss — understanding why an answer is wrong matters more than straightforward memorizing correct answers.

Some drivers study with a partner or in a group, reading the manual aloud and quizzing each other. Others use flashcards to memorize hazard class numbers and characteristics. The method that works best depends on how you learn, but spending at least a week reviewing the material before your test date is common practice.

Retaking the test if you do not pass

If you score below 24 correct answers, you can retake the test. Your state sets the rules for how long you must wait before your next attempt. Some states allow you to retake it the next business day; others require a waiting period of several days or a week. Check your state's DMV website or call your local DMV office to learn the retake policy.

When you retake the test, the questions will be different from your first attempt, though they cover the same topics. Use the time between attempts to review the sections where you struggled. If you failed questions about hazard classes, spend extra time on that section. If shipping papers tripped you up, focus there.

The difference between the hazmat test and other CDL tests

The hazmat test is shorter than the general CDL knowledge test, which typically has 50 questions. The hazmat test is also more specialized — it focuses only on hazardous materials, whereas the general CDL test covers vehicle operation, safety, and road rules. You cannot pass the hazmat endorsement without first holding a valid CDL, so the hazmat test assumes you already understand basic commercial driving.

Some drivers also pursue other endorsements, such as tanker or doubles/triples. Each endorsement has its own test with its own number of questions. The hazmat test stands alone and does not overlap with these other endorsement tests, though a driver can hold multiple endorsements at once.

What happens after you pass

Once you pass the 30-question hazmat test, your state DMV will add the hazmat endorsement to your CDL. This endorsement appears on your license and allows you to legally transport hazardous materials. The endorsement is valid for a set period — typically five years — after which you must renew it by passing the test again.

Your employer may also require a Transportation Security Administration (TSA) background check before you can haul hazmat. This is a separate process from the test and involves fingerprinting and a records review. The TSA check is not part of the DMV test, but many employers require it before hiring a hazmat driver.

Frequently Asked Questions

Can I take the hazmat test without taking the CDL test first?

No. You must hold a valid CDL before you can take the hazmat endorsement test. If you do not yet have your CDL, pass that test first, then schedule the hazmat test afterward.

How long does the hazmat test take?

The test itself usually takes 30 to 45 minutes, depending on how quickly you work through the 30 questions. Plan to spend additional time at the DMV for check-in and processing, so allow at least an hour total.

Is the hazmat test the same in every state?

The federal government sets the content standards for hazmat tests, so all states cover the same topics. However, each state's DMV writes its own questions, so the specific wording and examples may differ slightly between states.

What score do I need to pass the hazmat test?

You need to score 80 percent, which means 24 correct answers out of 30. A score of 23 or lower is a failing grade, and you will need to retake the test.

Can I use a calculator or notes during the hazmat test?

No. The hazmat test is closed-book and does not allow outside materials. You answer the questions based on what you have studied and memorized from the hazmat manual.