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.