Yes. Although you need to pay to take the exam each time you take it, you can retake the exam as many times as needed until you achieve a passing score of 80% or higher. For your employer to accept your application or maintain your position, they will need to see your passing grade on a CDL hazmat test. A valid CDL is also part of hazmat endorsement, so be sure to check your local guidelines for passing that test. Many states allow you to retake a CDL test within a certain number of days if you fail. Your CDL is step one in your hazmat certification, so make sure it is renewed and valid before your hazmat training.