What hazmat and tanker endorsements are, and why you might need them

A hazmat endorsement (also called an HM endorsement) and a tanker endorsement are separate add-ons to your commercial driver's license that let you haul specific kinds of cargo. The hazmat endorsement allows you to transport hazardous materials — things like explosives, flammable liquids, gases, poisons, and radioactive materials. The tanker endorsement lets you drive a truck with a tank permanently attached to it, whether that tank holds hazmat or not.

You do not need both endorsements to drive a tanker truck. A tanker endorsement alone covers non-hazardous liquids like milk, water, or food-grade oils. But if you want to haul hazardous materials in a tanker, you need both endorsements together. Many drivers get both at the same time because the jobs that pay best — fuel delivery, chemical transport, and specialized hauling — require the combination.

Each endorsement involves a written test at your state's Department of Motor Vehicles. The tests are separate, and you can take them in any order. Neither one requires behind-the-wheel testing, but both require you to already hold a valid commercial driver's license with a Class A or Class B rating.

Key Takeaways

  • Hazmat and tanker endorsements are two different add-ons; you need hazmat to carry dangerous materials and tanker to drive a permanently attached tank truck.
  • Both endorsements require passing a written test at your state's DMV, and you must already have a valid CDL before you can test for either one.
  • Hazmat endorsement requires a federal background check and fingerprinting, which takes several weeks and costs money separate from the test fee.
  • Study materials for both tests are free from the Federal Motor Carrier Safety Administration (FMCSA), and your state DMV handbook covers tanker rules.
  • Once you pass both tests, the endorsements appear on your CDL and remain valid for the same renewal period as your base license.

The hazmat endorsement: what the test covers and what the background check involves

The hazmat test has 30 questions and covers how to recognize hazardous materials, how to load and find them, what placards and labels mean, what to do in an emergency, and rules about routes and parking. You need to score at least 80 percent to pass. The test is based on Chapter 5 of the Commercial Driver's License Manual, which the FMCSA publishes free online.

Before you can take the hazmat test, you must pass a federal background check and be fingerprinted. This is a separate process from the written test and costs money — the fee varies by state but typically ranges from $25 to $100. The background check looks at criminal history, immigration status, and whether you have been disqualified from hazmat work before. The fingerprinting is usually done at your state's DMV office or a designated location, and results take two to four weeks to come back.

Once your background check clears, you can schedule the written test. Some states let you take it on the same day as your fingerprinting; others require you to wait for the background results first. Check with your state DMV to learn the exact order and timing for your location.

The tanker endorsement: test content and what makes tanker driving different

The tanker test has 20 questions and focuses on the physics and mechanics of driving a tank truck — how liquid shifts inside the tank during acceleration and braking, how to prevent rollovers, how to inspect a tanker before driving, and rules about speed and following distance. You need to score at least 80 percent. The test is based on Chapter 8 of the Commercial Driver's License Manual.

Tanker driving is riskier than driving a regular box truck because the liquid cargo moves around inside the tank, which changes how the truck handles. A half-full tank is actually more dangerous than a full one because the liquid sloshes more. The test makes sure you understand how to compensate — slower speeds, longer following distances, smoother acceleration and braking. There is no background check or fingerprinting for the tanker endorsement; you just study and test.

Some states combine hazmat and tanker into a single test, while others keep them separate. Check your state DMV website to see which applies where you live. If they are combined, you will answer all 50 questions in one sitting and need to pass both sections to get both endorsements.

How to study for both tests

The FMCSA publishes the Commercial Driver's License Manual free on its website. read it and read Chapter 5 (hazmat) and Chapter 8 (tanker). Many people read the chapters once, then take practice tests online to find weak spots, then read those sections again. This method usually takes four to six weeks if you study a few hours per week.

Your state DMV may also publish a study guide or practice test. Some states offer free online practice tests through their DMV website; others charge a small fee. Private test prep websites exist, but they are not required — the free FMCSA manual and your state's materials are enough to pass.

If you are already a CDL holder, you likely have the base knowledge. The hazmat and tanker chapters build on that foundation, so you are not starting from zero. Many drivers find the tanker chapter easier because it is more straightforward physics. The hazmat chapter has more memorization — placard colors, material classifications, emergency procedures.

The cost and timeline for getting both endorsements

The written test fees vary by state. Most states charge $10 to $20 per test, so if you take both separately, expect $20 to $40 total for the tests themselves. The hazmat background check and fingerprinting add $25 to $100 depending on your state. The tanker endorsement has no background check, so no extra fee beyond the test.

Timeline depends on the background check. If you start the hazmat process today, fingerprinting might happen within a week, but the federal background check takes two to four weeks. Once it clears, you can take the hazmat test. The tanker test has no waiting period — you can take it as soon as you are ready. Many drivers take the tanker test first while waiting for their hazmat background check to clear, then take the hazmat test once the results come back.

After you pass both tests, the endorsements are added to your CDL when ready or within a few business days, depending on your state. The endorsements stay on your license until your CDL expires and you renew it. You do not have to retake the tests at renewal unless your state has changed its rules or you have been disqualified from hazmat work.

What happens after you get the endorsements

Once both endorsements are on your CDL, you can legally drive a tanker truck carrying hazardous materials. Your employer will likely require additional training — company-specific procedures, safety protocols, and sometimes a ride-along with an experienced driver. This training is separate from the endorsement test and is required by federal law under the Hazmat Regulations.

You will also need to understand your employer's rules about which routes you can drive, where you can park, and how to handle emergencies. Some companies restrict hazmat tanker drivers from certain highways or cities. These rules are stricter than what the test covers, so ask your employer for their specific policies before your first day.

Your CDL record will show that you hold both endorsements. If you are ever convicted of certain crimes or disqualified from hazmat work, the endorsements can be removed. You would have to pass the tests again to get them back.

Frequently Asked Questions

Can I get a tanker endorsement without a hazmat endorsement?

Yes. A tanker endorsement alone lets you haul non-hazardous liquids like milk, water, or food-grade oils. You only need hazmat if the cargo is classified as dangerous. Many tanker jobs do not involve hazmat, though the highest-paying ones usually do.

Do I have to take both tests on the same day?

No. You can take them weeks or months apart. Many drivers take the tanker test first because there is no waiting period, then take the hazmat test once their background check clears. Your state DMV can tell you whether the tests are combined or separate in your location.

What disqualifies you from getting a hazmat endorsement?

The federal background check looks at felony convictions, certain misdemeanors, immigration status, and previous hazmat disqualifications. Specific crimes that disqualify you include violent felonies, drug trafficking, and crimes involving explosives or hazardous materials. Your state DMV can provide the full list.

Do hazmat and tanker endorsements expire?

They do not expire separately. They stay on your CDL until your license expires. When you renew your CDL, the endorsements renew with it unless you have been disqualified or your state has changed its rules. You do not retake the tests at renewal in most states.

Can I lose my endorsements after I get them?

Yes. A hazmat disqualification can happen if you are convicted of certain crimes, fail a drug test, or violate hazmat regulations. A tanker endorsement can be removed if you are convicted of crimes involving vehicles or hazardous materials. If either endorsement is removed, you must pass the test again to restore it.