
Iowa HazMat CDL Practice Test
Practice for your HazMat CDL exam with questions based on the official Iowa CDL handbook
Updated: August 2026
What's on the Iowa HazMat CDL test
Answering from memory beats re-reading — retrieval practice roughly doubles what you remember a week later. These free questions are modeled on the official HazMat CDL knowledge test.
- Questions
- 30
- To pass
- 24/30 correct (80%)
- Updated
- June 2026
- 100% free
The Iowa CDL HazMat test follows the AAMVA standard used by most states: 30 questions, with 24 correct answers (80%) needed to pass. A CDL learner's permit in Iowa costs $12 (Iowa Department of Transportation (Iowa DOT) fee schedule, June 2026).
Start the practice testIowa HazMat CDL Practice Test
The shippers package hazardous materials, they must certify that this was done according to the regulations. The only exception is when:
- The driver is given a sealed cargo compartment
- The shipper is a private carrier carrying his or her own product
- The shipment is a hazardous waste
When companies send out dangerous goods, they must follow rules to pack them safely. The only time they don't have to is if the company is moving its own products and not selling the service.
How many hazard classes are there?
- 3
- 9
- 10
There are 9 different types of dangers or hazard classes that truck drivers need to know about when they are carrying goods. These classes help them understand what kind of special care or rules they need to follow to keep the roads safe.
Apart from the shipping papers and the packages, what other two locations must display the hazardous material identification number?
- on the front bumper and on the inside of the cab door.
- on the exhaust system and on a decal on the dashboard.
- on the driver’s door and on the steering column.
- on all bulk packaging and on the cargo tanks.
Beyond shipping papers and packages, the hazardous material identification number is also required to be shown on cargo tanks and on all bulk packaging.
A driver places placards on their vehicle in order to:
- to show the vehicle’s maximum legal weight.
- to advertise the company hauling the load.
- to communicate risk.
- to indicate the driver’s route and destination.
Placards are exterior signs on a vehicle that alert others to the presence of hazardous materials and indicate the hazard class of the load.
Why is the shipper required to sign the shipping paper?
- To confirm the carrier has inspected and approved the shipment for transport
- To certify that it has prepared the shipment in accordance with regulations
- To confirm the carrier has received payment for transporting the shipment
The shipping paper has to contain the shipper’s certification, signed by the shipper, confirming the shipment was prepared in compliance with the applicable regulations.
Carriers must provide each driver who hauls Division 1.1, 1.2, or 1.3 materials with:
- a written list of emergency response phone numbers for local fire departments.
- a copy of FMCSR Part 397.
- a copy of the shipper’s facility address and receiving hours.
Carriers are required to give drivers transporting explosives a copy of 49 CFR 397, “Transportation of Hazardous Materials; Driving and Parking Rules.” This part includes rules on hazardous materials routing, including factors to consider when selecting an appropriate route.
Hazardous material identification numbers must be shown on portable tanks, cargo tanks, and other bulk packages. Regulations require black ______ numbers.
- 75 mm
- 125 mm
- 100 mm
Hazardous material identification numbers must appear on portable tanks, cargo tanks, and other bulk packaging. The rules specify black 100 mm (3.9 inch) numbers on orange panels, placards, or on a white diamond-shaped background when placards are not required.
Helium is classified as a Class ____ hazardous material.
- 2
- 9
- 1
A hazardous material’s class indicates the type of risk it presents. There are nine hazard classes in total. Class 2 covers gases, including flammable gases (2.1) like propane, non-flammable gases (2.2) like helium, and toxic gases (2.3) such as compressed fluorine.
Who must select the safest route when transporting placarded radioactive materials?
- The state highway department
- The receiver/consignee
- The carrier
If placarded radioactive materials have to be transported, the carrier is responsible for choosing the safest route. Once the route is selected, the carrier must inform the driver about the radioactive materials and provide the driver with the planned route.
With most hazardous materials, you may park within 5 feet of the road briefly. If your work requires it. The materials that are the exception and do not allow parking this close to the road are?
- Acids and poisons
- Corrosives and oxidizers
- Explosives 1.1 thru 1.3
When it comes to parking near the road with hazardous materials, you usually can if it's quick and needed for work. But, don't do this with very explosive materials (like fireworks or dynamite), flammable stuff (like gasoline or propane), because it's too dangerous.
A truck as hazardous material, when can it be moved without the placards on the truck?
- Never
- When the shipper says it's ok
- To protect life or property
If a truck is carrying dangerous materials, it usually must have special signs (placards) on it to show that it is hazardous. However, there is one exception to this rule. The truck can be moved without these signs only if it is necessary to protect people's lives or to prevent property from being damaged. This means safety is the top priority, and in an emergency situation, the truck can be moved even without the placards.
Which option lists a required criterion for a package to qualify as non-bulk packaging?
- A water capacity of 454 kg (1,000 pounds) or less if it is used as a receptacle for a gas
- A maximum net mass of 400 kg (882 pounds) or less and a maximum capacity of 450 L (119 gallons) or less if it is used as a receptacle for a solid
- A maximum capacity of 450 L (119 gallons) or less if it is used as a receptacle for a liquid
- All of the above
Non-bulk packaging must meet defined limits when used as a container for solids, liquids, or gases. It qualifies as non-bulk if it is: 450 L (119 gallons) or less for liquids; 400 kg (882 pounds) or less and 450 L (119 gallons) or less for solids; and 454 kg (1,000 pounds) or less for gases.
If you are transporting Division 1.2 or 1.3 materials, what is the minimum distance you must park from a bridge, tunnel, or building?
- 300 feet
- 150 feet
- 250 feet
- 50 feet
With a load of Division 1.2 or 1.3 explosives, you are required to park no closer than 300 feet from any bridge, tunnel, or other structure.
Under what circumstances may a shipper shorten (abbreviate) the proper shipping name or hazardous material identification number on a shipping paper?
- Only if regulations specifically authorize the shipper to do it
- Only when the shipment is moving by highway within the same state
- Only when the material is non-flammable and low hazard
A shipper is not allowed to abbreviate a hazardous material’s identification number, hazard class, or proper shipping name unless the regulations explicitly permit that abbreviation. Abbreviations can interfere with correct identification and create safety risks.
You must stop before a railroad crossing if your vehicle is transporting _______ of chlorine.
- at least 100 gallons
- any amount
- more than 110 gallons
If you are transporting any quantity of chlorine gas, you are required to stop at every railroad crossing and use extra caution before crossing. A train collision could cause a chlorine release, which is very dangerous because chlorine gas is poisonous. (If chlorine is being hauled in cargo tanks, a gas mask must be available in the cab.) Chlorine is also a strong oxidizer and can react with flammables to start fires, which may spread corrosive or toxic gases.
You may allow another person to watch your vehicle only when it is…
- parked at a public rest area while you take a break.
- being watched by any licensed driver.
- on the property of the shipper, carrier, or receiver.
You may let someone else watch your vehicle only when you are on the property of the shipper, carrier, or consignee/receiver, since those parties understand the hazards and how to handle them.
Which hazard class covers both flammable gases and non-flammable gases?
- 2
- 4
- 9
A material’s hazard class indicates the type of risk it presents. There are nine hazard classes. Hazard Class 2 is for gases, including flammable gases (2.1) like propane, non-flammable gases (2.2) like helium, and toxic gases (2.3) such as compressed fluorine.
If you think there may be a cargo fire in your trailer and the cargo doors feel hot, what should you do?
- crack the doors slightly to let heat and smoke escape.
- leave the doors closed.
- swing the doors fully open to ventilate the trailer.
Hot cargo doors make it more likely a fire is burning inside. Opening the doors would add oxygen and can intensify the fire. Keeping the doors shut limits oxygen, so the fire may only smolder until firefighters arrive.
By law, how regularly must employees involved in transporting hazardous materials be tested?
- Within 90 days of hire and then every 3 years
- Within 90 days of hire and then every 6 months
- At least every 5 years
People who transport dangerous stuff must be tested within 90 days of starting their job and then every 3 years to make sure they know how to handle these materials safely.
Symbol column, the letter "G" stands for?
- Identifies the proper shipping name for which one or more technical names of the hazardous material must be entered in parentheses, along with the basic description
- Identifies the proper shipping name
- Gases
The letter "G" means you need to write the hazardous material's specific name next to its general name when shipping it.
All Iowa CDL tests
The Iowa HazMat test is one section of the Iowa CDL knowledge exam. For the full set — general knowledge questions, every endorsement section, and Iowa’s permit requirements in one place — go to the Iowa CDL permit practice test.
Other Iowa CDL Practice Tests
HazMat Practice Tests in Nearby States
More free CDL practice tests
About the HazMat Test in Iowa
The HazMat endorsement test is required in Iowa for drivers who transport hazardous materials. It covers placarding, labeling, loading procedures, emergency response, and compliance with federal hazmat regulations. A TSA background check is also required.
The HazMat test is part of the CDL written exam administered by the Iowa Department of Motor Vehicles. You must pass this test along with the other required written tests to receive your Commercial Learner's Permit (CLP) in Iowa.
Our practice questions are built from the official Iowa CDL handbook and federal FMCSA regulations. Each question includes a detailed explanation to help you understand the material, not just memorize answers.
Iowa HazMat endorsement facts
| Fact | Value | Source |
|---|---|---|
| Hazardous materials (H) endorsement fee | $5State fee only — the TSA threat-assessment fee is paid separately to TSA | iowadot.gov |
| Haz-mat/tank combination (X) endorsement fee | $10Requires both the tanker and the hazardous-materials knowledge tests plus the fingerprint-based threat assessment | iowadot.gov |
| Card reprint when an endorsement is added off-cycle | $10Charged on top of the endorsement fee if you add it outside your regular renewal period | iowadot.gov |
| Card-payment surcharge | $1.50 when paying by credit cardCounty locations may charge an additional convenience fee | iowadot.gov |
| Out-of-county surcharge | $10 may apply at a county office outside where you liveSet by the county, not the Iowa DOT | iowadot.gov |
| Minimum age | 18 for an Iowa CDL; 21 to drive a commercial motor vehicle in interstate travel | iowadot.gov |
| Interstate driving-record check | Run for every CDL applicant; must show you are eligible for commercial licensing in all other states | iowadot.gov |
| Entry-Level Driver Training (ELDT) | Required for a first Class A or B CDL, for CDL upgrades, and for the H, P and S endorsementsIowa DOT confirms your record on the FMCSA Training Provider Registry before it will test you | iowadot.gov |
| Pass mark | Stated as questions you may miss: 10 of 50 (general knowledge), 6 of 30 (hazmat), 5 of 25 (air brake), 4 of 20 (combination, passenger, school bus, doubles/triples, tank) | iowadot.gov |
| Hazmat knowledge test | 30You may miss 6 | iowadot.gov |
| Tank endorsement knowledge test | 20You may miss 4 | iowadot.gov |
| Where to take the knowledge test | Any Iowa DOT DMV or county treasurer location, by appointmentMore sites are listed on the CDL Testing Locations page | iowadot.gov |
| Minimum CLP holding period | 14 daysELDT must also be satisfied before the skills and drive test | iowadot.gov |
| What a CLP cannot do | No hazmat load, no tank vehicle with un-purged hazmat residue, no cargo in a tank, no passengers and no cell phone use | iowadot.gov |
| Endorsements a CLP can carry | Passenger (P), school bus (S) and tank vehicle (N) onlyHazMat and doubles/triples go on the CDL, never on the permit | iowadot.gov |
| Self-certification | Four categories — non-excepted interstate, excepted interstate, non-excepted intrastate, excepted intrastate — chosen every time you receive a CDL product | iowadot.gov |
| Medical certificates | Digital in Iowa — your examiner submits the certificate electronicallyeffective October 23, 2025 | iowadot.gov |
| Licensing agency | Iowa Department of Transportation (Iowa DOT), Motor Vehicle Division | iowadot.gov |
| HazMat knowledge test | Taken at the DMV and required again at every HME renewalThe endorsement is not issued or renewed until both the test and the TSA background check are done | iowadot.gov |
| TSA fingerprint-based background check | Required every five years | iowadot.gov |
| ELDT before the hazmat test | First-time HME applicants must complete ELDT before taking the knowledge test | iowadot.gov |
| How to apply for the threat assessment | Online or through the HazPrint help desk on 855-347-8371 — the application and fee must be done before you are fingerprintedYou cannot fill the application in at the fingerprinting site | iowadot.gov |
| Proof of status for the endorsement | Extra identification — a U.S. passport or birth certificate — to prove citizenship or permanent residency | iowadot.gov |
| After TSA clears you | Bring the results letter to a DMV appointment to have your license issued with the endorsementCall the HazPrint help desk if the letter has not arrived after six weeks | iowadot.gov |
| Renewing with a hazmat endorsement | Must be done in person, because the hazmat knowledge test is retaken each renewal | iowadot.gov |
| Farm-service alternative to the H endorsement | A restricted CDL covers liquid fertilizers (3,000 gallons or less) and solid fertilizers for farm-related service industries, with no CDL knowledge or driving testValid up to 210 days a calendar year, within 150 miles of the place of business | iowadot.gov |
| What the hazmat test covers | Recognizing, handling and transporting hazardous materials | iowadot.gov |
| If TSA finds a security threat | TSA notifies you and the state denies issuance of the endorsementThe check covers criminal, immigration and FBI records | iowadot.gov |
| TSA security threat assessment fee (federal) | $85.25Non-refundable; paid to TSA, not the stateeffective January 1, 2025 | tsa.gov |
| TSA reduced fee (valid TWIC holders, where the state accepts it) | $41 | tsa.gov |
| TSA clearance validity | 5 years | tsa.gov |
| When to enroll with TSA | At least 60 days before you need the endorsementTSA says some applications take more than 45 days | tsa.gov |
| Combination hazmat/tank (X) endorsement | For tank drivers hauling placarded hazardous materials — both the tank and hazmat knowledge examinations | iowadot.gov |
How to add the HazMat endorsement in Iowa
- If this is your first hazmat endorsement, complete Entry-Level Driver Training before you take the HME knowledge test. Source
- Apply for the TSA threat assessment through HazPrint — online or by calling the help desk on 855-347-8371 — and pay the $85.25 application fee before you go to be fingerprinted. Source
- Get fingerprinted at a HazPrint site, bringing two forms of ID, then wait for TSA’s results letter — call the help desk if it has not arrived after six weeks. Source
- Take the hazmat knowledge test at the DMV — 30 questions, 6 of which you may miss. Iowa requires the test again at every HME renewal, and the endorsement is not issued until both the test and the background check are done. Source
- Bring the TSA letter and proof of citizenship or permanent residency to a DMV appointment to have the license issued with the endorsement, and pay the $5 hazardous-materials endorsement fee (plus $10 for a new card if you are adding it outside your renewal period). Source
Official Iowa Department of Transportation (Iowa DOT), Motor Vehicle Division links
- Iowa DOT: Commercial Drivers
- Iowa DOT: How to Get a CDL
- Iowa DOT: Driver's License Fees
- Iowa DOT: CDL Testing
- Iowa DOT: CDL Testing Locations
- Iowa DOT: Schedule an Appointment
- Iowa DOT: Hazardous Materials endorsement
- Iowa CDL Manual (PDF)
- Iowa DOT: Entry Level Driver Training
- Iowa DOT: Medical Cards & Certification
As of September 2, 2026, verified against Iowa Department of Transportation (Iowa DOT), Motor Vehicle Division.
Iowa CDL questions
- How many questions are on the Iowa CDL knowledge tests?
- Iowa DOT publishes the count and the number you may miss for each test: general knowledge 50 (miss 10), combination vehicle for Class A 20 (miss 4), air brake 25 (miss 5), hazmat 30 (miss 6), and tank, passenger, school bus and doubles/triples 20 each (miss 4). There is also a 25-question Iowa operator test where it applies. Source
- What does Iowa require for a hazmat (H) endorsement?
- Entry-Level Driver Training first if it is your first HME, then the TSA threat-assessment application through HazPrint (online or on 855-347-8371) and fingerprinting, then the 30-question hazmat knowledge test at the DMV. Iowa charges $5 for the endorsement — $10 for the haz-mat/tank X combination — plus $10 to reprint the card if you add it outside your renewal period. The knowledge test is retaken at every renewal and the TSA check repeats every five years, so a hazmat CDL cannot be renewed online. Source
- How old do you have to be to get a CDL in Iowa?
- The minimum age for an Iowa CDL is 18, but you must be 21 to operate a commercial motor vehicle in interstate travel. Under 21 you are limited to driving inside Iowa, and self-certifying to an intrastate category adds a “K” restriction to the license. Source
Save your misses — the app re-asks them at the right time
Web progress isn't saved when you finish. With a subscription, the app keeps every missed question and brings it back with spaced review — and unlocks all 2,500+ questions. Free to start.
4.95,800+ ratingsacross app stores
