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IA CDL Hazardous Materials (HazMat) Practice Test 2025

5 min

Transporting products that can pose a risk to health, safety, property or the environment is a task that shouldn’t be taken lightly. Professional drivers must be trained for this kind of job, which they can perform only after obtaining a Hazardous Materials (H) endorsement on their Commercial Driver’s License (CDL). Some common types of hazardous materials (HazMat) are explosives, flammable gases, flammable liquids and toxic substances.

You wouldn’t want an unqualified driver to be responsible for such a dangerous task. That’s why in Iowa, all drivers must pass a written knowledge test before they can transport such high-risk cargo. The test covers various topics related to transporting hazardous materials, such as safe loading and unloading procedures, emergency protocols and hazard classification.

While this is a complex subject, adequate preparation will increase your chances of passing the written exam. Our CDL hazardous materials practice tests closely reflect the official exam, which is based on the official 2025 CDL manual (https://driving-tests.org/iowa/ia-cdl-handbook/). You get unlimited attempts and there is no time limit.

IA commercial driver's license
Based on the official IA CDL HandbookHandbook‑based (2025) + exam‑taker feedback
This test is a Premium member exclusive. You'll get

All 650 exam-like questions specific to Iowa

Interactive learning with AI personal tutor

Unique 360° Virtual Road Simulations

Get your money back if you don’t pass

Accuracy & authorship

Steven Litvintchouk, M.S., Chief Educational Researcher at Driving-Tests.org

Reviewed for legal and handbook accuracy:

Steven Litvintchouk

M.S., Chief Educational Researcher (ACES member)

Last verified for accuracy on

Andrei Zakhareuski, Co-founder & CEO at Driving-Tests.org

Test design and learning experience oversight:

Andrei Zakhareuski

Co-founder & CEO, Driving-Tests.org

How to use this practice test

  1. Start here. One of 4 free Iowa tests. ~5 min. Read explanations as you go.
  2. Cover more ground. All tests have different questions - no repeats.
  3. Finish strong. Try the Exam Simulator for a full-length run.

Why this works

  • Exam-like questions from the current handbook + real test-taker patterns. Explanations cite the manual.
  • AI Assistant explains tricky items in plain language.
  • Performance Insights show your weak topics and what to study next.
  • Challenge Bank™ saves your mistakes for targeted practice.

Actual DOT permit test: What to expect?

The Iowa permit test has 30 questions. You must get 24 correct (80%) to pass.
  • Where: Any Iowa DOT office (find locations)
  • Bring: ID + SSN + residency proof + permit/license fee (see checklist)
  • If you fail: Retake after 1 calendar day.
  • Commonly missed: safe following distance (3-second rule), passing and lane marking rules.
  • Ready to schedule? Book your IA DOT appointment

About the Iowa CDL

Our practice tests are designed to help you learn and better understand the subject at hand. Just like the official CDL HazMat exam, each practice test has 30 questions on hazardous materials. To pass, you’ll need to provide a correct answer to 80% of the questions. Our smart system provides a detailed explanation after every question, allowing students to identify their mistakes and better understand the subject at hand. With immediate feedback, you won’t have to wait until the end of the test to know which questions you got wrong.

Pro tip: Open our complete HazMat guide in another tab while you practice on our practice tests. Students show higher success at remembering essential information when they associate it with the question at hand. This way, you’ll also understand how the various principles of HazMat work since you’re not just looking for the correct answer.

HazMat drivers can secure a stable and profitable career, but employers pay differently across the country. If you decide to move to another state, your CDL and its endorsements are not transferable. In this case, you can use our HazMat practice test collection, which features similar tests for all 50 US states, including Washington, DC.

We know what it takes to pass. And we’ve got the proof.

Driver’s Ed is - nobody wants to set foot inside the DOT. That’s why millions of learners trust us for simple, visual, effective prep.

An official & trusted partner in driver education

We are an officially recognized FMCSA Entry-Level Driver Training provider and a proud partner to over 2,500 libraries. We work with safety organizations like GHSA and the National Safety Council to help create safer roads for everyone.

A smarter way to study

Challenge Bank™

Our trademarked system automatically saves questions you miss, creating personalized tests that target your weak spots until you’ve mastered the material.

AI-powered feedback

Get smarter as you study. Our new AI-powered feedback provides detailed, question-level insights to help you understand the why behind each answer.

Interactive handbook

Go beyond the boring black-and-white manual. Our interactive handbook lets you read, listen with an MP3 audio version, or even chat with it to find the information you need, faster.