What Hazmat and Tanker Endorsements Are

A hazmat endorsement (H endorsement) and a tanker endorsement (N endorsement) are two separate additions to your commercial driver's license that allow you to haul specific cargo. The hazmat endorsement lets you transport materials the Department of Transportation classifies as hazardous — explosives, flammable liquids, poisons, radioactive materials, and others. The tanker endorsement lets you operate any vehicle designed to carry liquids or gases in bulk, whether that cargo is hazardous or not.

You do not need both endorsements to drive a tanker truck. If you haul non-hazardous liquids like food-grade vegetable oil or water, you need only the tanker endorsement. If you haul hazardous materials in any container — a tanker, a flatbed with drums, a box truck with boxes of chemicals — you need the hazmat endorsement. If you haul hazardous liquids in a tanker, you need both.

Both endorsements require you to pass a written knowledge test specific to that endorsement, in addition to your CDL written test. The hazmat test covers regulations, placarding, shipping papers, and emergency procedures. The tanker test covers vehicle handling, cargo surge, and safe loading and unloading of liquid cargo.

Key Takeaways

  • Hazmat endorsement (H) allows you to transport materials classified as hazardous by the Department of Transportation; tanker endorsement (N) allows you to operate any bulk liquid or gas tanker.
  • You need hazmat only if your cargo is hazardous, tanker only if your vehicle is a tanker, and both if you haul hazardous materials in a tanker.
  • Each endorsement requires passing a separate written test beyond your CDL exam, and hazmat also requires a Transportation Security Administration background check.
  • Hazmat endorsement must be renewed every three years; tanker endorsement renews with your CDL every four or eight years depending on your state.
  • Many employers require one or both endorsements for certain driving positions, and having them can increase your earning potential.

Hazmat Endorsement Requirements and Testing

To get a hazmat endorsement, you must first hold a valid CDL. You then take a written test at your state's Department of Motor Vehicles covering hazmat regulations, hazard classes, placarding requirements, shipping papers, and what to do in an emergency. The test is typically 30 questions, and you must score at least 80 percent to pass. Your state may allow you to study using the official CDL manual or hazmat-specific study guides.

Before your hazmat endorsement is issued, you must pass a Transportation Security Administration (TSA) background check. This check looks for criminal history, immigration violations, and other security concerns. The TSA charges a fee for this check, which varies by state but typically ranges from $75 to $175. The background check can take several weeks, so plan accordingly if you need the endorsement by a specific date.

Once issued, your hazmat endorsement is valid for three years. When it expires, you must renew it by passing the written test again and undergoing another TSA background check. You do not need to renew your entire CDL to renew hazmat — you can renew just the endorsement at your state DMV.

Tanker Endorsement Requirements and Testing

The tanker endorsement requires you to hold a valid CDL and pass a written test covering tanker-specific topics: how liquid surge affects braking and handling, safe loading and unloading procedures, and vehicle inspection for tankers. The test is typically 20 questions, and you must score at least 80 percent. Study materials are available through your state's CDL manual or tanker-specific guides.

Unlike hazmat, the tanker endorsement does not require a background check. Once you pass the test, the endorsement is added to your license. The tanker endorsement renews on the same schedule as your CDL — every four years in most states, or every eight years if you are a military veteran or meet certain other criteria. You renew it by passing the written test again at your state DMV.

Some states allow you to take both the hazmat and tanker tests on the same day, which can save you time if you need both endorsements. Check with your state's DMV to see whether you can schedule both tests together.

What You Can and Cannot Haul With Each Endorsement

With a hazmat endorsement alone, you can haul hazardous materials in any type of vehicle — a box truck, a flatbed with drums, a small tanker, or a large tanker. You cannot, however, haul non-hazardous liquids or gases in a tanker vehicle designed to carry bulk cargo, because the tanker endorsement is what authorizes that. With a tanker endorsement alone, you can haul any non-hazardous liquid or gas in a tanker — milk, water, food-grade oils, propane, or compressed air — but you cannot haul anything the DOT classifies as hazardous.

With both endorsements, you can haul hazardous materials in a tanker, which is the most common scenario for drivers hauling gasoline, diesel, or other flammable liquids. You can also haul non-hazardous cargo in a tanker, or hazardous cargo in any other vehicle type.

If you drive a tanker but do not have the tanker endorsement, you are breaking the law, even if your cargo is not hazardous. If you haul hazardous materials without the hazmat endorsement, you are also breaking the law. Violations can result in fines, out-of-service orders, and loss of your CDL.

How Endorsements Affect Your Job Prospects and Pay

Many trucking companies require drivers to hold a hazmat endorsement, a tanker endorsement, or both, depending on the routes and cargo they operate. Companies that haul fuel, chemicals, or other hazardous materials will not hire you without hazmat. Companies that haul milk, water, or other bulk liquids will not hire you without tanker. Some regional or local delivery companies may not require either, but most long-haul and specialized cargo operations do.

Drivers with hazmat and tanker endorsements typically earn more than drivers with a CDL alone. The exact difference varies by company, region, and market conditions, but many employers offer a pay premium for drivers who hold these endorsements. Some companies also offer to cover the cost of obtaining the endorsements if you agree to work for them for a set period.

If you are early in your CDL career and unsure whether you need these endorsements, ask potential employers directly what they require. If you plan to work in specialized cargo or fuel transport, obtaining both endorsements before you start job hunting can make you a more competitive candidate.

Renewing and Maintaining Your Endorsements

Hazmat endorsement renewal requires passing the written test again and undergoing another TSA background check every three years. You can renew by mail in some states, but most states require you to appear in person at the DMV. Plan to renew at least 30 days before your endorsement expires to allow time for the TSA background check to clear.

Tanker endorsement renewal requires passing the written test again every four or eight years, depending on your state and whether you may have access to for the extended renewal period. You do not need a background check for tanker renewal. In most states, you can renew by mail or online if you have not had any violations or medical changes.

If your hazmat endorsement expires while you are driving, you lose the right to haul hazardous materials when ready. If your tanker endorsement expires, you lose the right to operate a tanker. Some employers monitor their drivers' endorsement expiration dates and will notify you when renewal is due. It is your responsibility to track these dates and renew on time.

Common Mistakes When Getting or Renewing Endorsements

One common mistake is assuming you need hazmat to drive a tanker. You do not — you need tanker to drive the vehicle type, and hazmat only if the cargo is hazardous. Another mistake is waiting until your endorsement is about to expire to renew, which can leave you unable to work if the TSA background check takes longer than expected or if you fail the written test and need to retake it.

Some drivers also fail to update their employer when their endorsement status changes. If you lose an endorsement due to expiration or a violation, tell your employer when ready rather than waiting for them to discover it. Driving without a required endorsement can result in your company being fined and can damage your professional reputation.

Finally, do not assume your state's rules match another state's rules. Renewal timelines, test content, and background check procedures vary by state. If you move or work across state lines, check your new state's DMV website to understand what you need to do to maintain your endorsements there.

Frequently Asked Questions

Can I get hazmat and tanker endorsements at the same time?

Yes. You can take both written tests on the same day at your state DMV. However, you will still need to pass the TSA background check for hazmat separately, which can take several weeks. Some people take the tanker test first, then the hazmat test once the background check clears.

What happens if I fail the hazmat or tanker test?

You can retake the test, usually after waiting a short period (often 24 hours to one week, depending on your state). There is no limit to how many times you can retake it, but you will pay the test fee each time. Most people pass on the second attempt if they study the material more thoroughly.

Do I need hazmat endorsement to haul propane?

Yes. Propane is classified as a hazardous material by the Department of Transportation. You need both hazmat and tanker endorsements to haul propane in a tanker truck. You also need hazmat to haul it in any other vehicle type.

Can my hazmat endorsement be suspended or revoked?

Yes. Hazmat endorsement can be suspended or revoked if you are convicted of certain crimes, if you violate hazmat regulations, or if you fail a security check. If this happens, you must reapply and pass the TSA background check again. Tanker endorsement can be suspended for violations but is less commonly revoked than hazmat.

How much does it cost to get both endorsements?

Costs vary by state. Typically, the hazmat test fee is $10 to $50, the tanker test fee is $10 to $50, and the TSA background check for hazmat is $75 to $175. Some states charge additional processing fees. Total cost is usually between $100 and $300, but check your state DMV website for exact fees.