Hazmat vs. Tanker Endorsement: H, N and X
Updated October 27, 2026
Three CDL endorsements cover hazardous and liquid loads, and drivers often mix them up. H is about what you haul (hazardous materials), N is about how you haul it (in a tank), and X is both together. Here’s who needs which.
The three endorsements
| Endorsement | Covers | What it takes |
|---|---|---|
| H (hazardous materials) | A vehicle of any size carrying hazmat in amounts that require placards | Hazmat knowledge test, TSA security threat assessment, and entry-level hazmat theory training for first-time applicants |
| N (tank vehicle) | A tank vehicle, as defined below | Tank vehicle knowledge test |
| X (hazmat and tank combined) | A tank vehicle carrying placarded hazmat | Everything for both H and N |
Federal rules (49 CFR 383.153) list X as the code for the combination of the tank vehicle and hazardous materials endorsements, and many states print it that way on the license. Some states may show H and N separately instead. Ask your state how it displays them.
What counts as a tank vehicle
Under 49 CFR 383.5, a tank vehicle carries liquid or gaseous materials in one or more tanks that:
- each have a rated capacity of more than 119 gallons, and
- together have a rated capacity of 1,000 gallons or more,
and are permanently or temporarily attached to the vehicle or chassis. The cargo does not have to be hazardous. A water truck or a milk tanker that meets these numbers needs N.
Who needs which
| Your load | Endorsement |
|---|---|
| A gasoline tanker | X (or H and N) |
| A placarded van of drums and boxes | H |
| A water tanker, 3,000 gallons | N |
| A pickup with a placarded load of cylinders | H, on a CDL |
| A propane delivery truck (bobtail) | X (or H and N) |
Differences in getting them
- Background check: only H, and therefore X, needs the TSA security threat assessment, with fingerprints and a fee. N does not.
- Training: federal entry-level driver training applies to first-time H applicants (theory only). It does not apply to N.
- Tests: H and N each have their own knowledge test. To get X, you pass both.
- Renewal: keeping H (or X) means a current TSA threat assessment and, under 49 CFR 383.71, passing the hazmat knowledge test again when you renew your CDL.
Read the full steps in the hazmat endorsement guide, and see the tank-specific hazmat rules in cargo tank rules.
Check your knowledge
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What does the X endorsement on a CDL mean?Answer: AX is the code for the combination of the tank vehicle and hazardous materials endorsements, used for drivers who haul placarded hazmat in tank vehicles.
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Which vehicle is a tank vehicle that needs the N endorsement?Answer: BA tank vehicle has tanks each over 119 gallons that total 1,000 gallons or more. Two 600-gallon tanks total 1,200 gallons, so N is needed. The drums are 119 gallons or less each.
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You will drive a placarded tanker hauling gasoline. Which endorsement covers it?Answer: CGasoline in a tank vehicle needs both the hazmat and tank vehicle endorsements, which together are the X endorsement (or H and N shown separately in some states).
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A driver hauls drinking water in a 3,000-gallon tank truck that requires a CDL. Which endorsement does this job need?Answer: DThe N endorsement depends on the tank, not the cargo. A 3,000-gallon tank meets the tank vehicle definition, but water is not hazmat, so H is not needed.
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A box truck carries 2,000 pounds of placarded hazmat in drums and boxes, and no tanks. Which endorsement does the driver need?Answer: AA placarded load needs the H endorsement on a vehicle of any size. Without tanks that meet the tank vehicle definition, N is not needed.
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Which endorsement requires a TSA security threat assessment?Answer: BThe TSA threat assessment, with fingerprints and a fee, is required for the hazardous materials endorsement. X includes hazmat, so it needs it too. The N endorsement alone does not.
Pass your hazmat endorsement test on the first try
- All 181 questions on hazard classes, shipping papers, placards, loading, cargo tanks, driving and parking rules and emergencies
- An explanation for every answer, from the CDL manual and the federal hazmat rules
- Unlimited full 30-question practice tests, scored like the real one (80% to pass)