What Is the CDL Hazmat Endorsement?
The HazMat endorsement is shown as an H endorsement. Drivers who qualify for both HazMat and Tank Vehicle endorsements receive the X endorsement — is a federally required credential that authorizes CDL holders to operate vehicles transporting regulated hazardous materials. Whether you're hauling explosives, toxic gases, flammable liquids, or radioactive substances, federal law requires this endorsement any time your vehicle must display placards under federal standards. The HazMat (H) endorsement may be added to a Class A, Class B, or Class C CDL when the driver operates a commercial motor vehicle that requires placarded hazardous materials under federal regulations. The endorsement requires a HazMat knowledge test and TSA Security Threat Assessment.
How to Get Your CDL Hazmat Endorsement: Step-by-Step
Obtain Your CLP (Commercial Learner's Permit)
Before applying for any endorsement, you must first pass the CDL general knowledge written test and receive your Commercial Learner's Permit.
Complete ELDT Hazmat Theory Training
Per FMCSA regulations, you must complete the Entry-Level Driver Training (ELDT) Hazmat theory course through an approved provider. Your results are automatically submitted to the federal Training Provider Registry.
Complete the TSA Security Threat Assessment (STA)
Applicants for a HazMat endorsement must complete the TSA Security Threat Assessment, including fingerprinting at an authorized enrollment center. TSA approval is required before the state DMV may issue the H endorsement.
Visit an Enrollment Center for Fingerprinting
Bring acceptable identification documents required by TSA to an authorized enrollment center for fingerprinting. TSA publishes a list of acceptable identity and immigration documents for HazMat applicants.
Wait for TSA Approval
TSA reviews the applicant's background and determines eligibility for the HazMat endorsement. The approval status is provided through the required channels, and the state DMV completes the endorsement issuance process.
Pass the DMV Hazmat Knowledge Test
Visit your local DMV to take the 30-question computer-based written test. You need a score of at least 80% to pass.
Receive Your H Endorsement
Once both requirements are met, your state DMV will mail you an updated CDL with the "H" endorsement printed on it.
What Does the TSA Background Check Cover?
Unlike other CDL endorsements, the Hazmat H Endorsement requires a federal TSA Security Threat Assessment (STA) because hazardous materials can pose a national security risk. The review focuses on the following key areas:
1. Fingerprinting
You must appear in person for biometric enrollment. Your fingerprints are cross-referenced against the FBI's criminal database.
2. Criminal History
TSA checks for specific federal disqualifying offenses — including treason, terrorism, murder, and robbery. A prior conviction for one of these crimes can result in a permanent or temporary denial of your application.
3. Immigration & Legal Status
Applicants must provide proof of U.S. citizenship or valid lawful permanent resident status (Green Card), or an eligible work authorization document.
4. How Long Does TSA Review Take?
TSA processing times vary. Applicants should apply early because some Security Threat Assessments may require additional review and take longer to complete. Apply early to avoid delays in your overall licensing timeline.
The 9 Hazmat Placard Classes: Visual Guide
A significant portion of the DMV Hazmat knowledge test covers placard identification and hazard class recognition. Here's a quick visual reference for the most commonly tested hazardous materials classes:
Top Topics on the CDL Hazmat Knowledge Test
Based on what test-takers consistently report, these are the highest-frequency topics you'll need to master:
- Placarding Rules: Know the difference between Table 1 materials (such as explosives and poison gas, which require placards regardless of quantity) and Table 2 materials (such as flammable solids, which only require placards when the total weight exceeds 1,001 lbs).
- Segregation and Loading Restrictions: Certain hazardous materials can never be loaded together. For example, Certain hazardous materials cannot be loaded or transported together because of chemical incompatibility. Drivers must follow DOT segregation requirements and shipping documentation.
- Railroad Crossing Procedures: When required to stop at railroad crossings, drivers of placarded hazardous materials vehicles must stop between 15 and 50 feet before the nearest rail. The driver must look and listen carefully before crossing and proceed only when safe.
- Tire Inspection Requirements: Drivers of placarded vehicles are required by law to inspect all tires before driving and again at least every 2 hours or 100 miles, whichever comes first.
Hazmat Test Requirements by State
While hazardous materials regulations follow federal 49 CFR standards nationwide, individual state DMVs set their own rules for test fees, retake policies, and appointment scheduling. Select your state for specific requirements:
CDL Hazmat Endorsement — Frequently Asked Questions
Q: How many questions are on the Hazmat CDL test?
A: Many states use a HazMat knowledge test with approximately 30 questions, but the exact number and format are determined by each state licensing agency.
Q: What's the passing score for the Hazmat test?
A: Most states require an 80% passing score for the HazMat knowledge test, but applicants should verify their state's CDL handbook for exact requirements.
Q: Does the Hazmat endorsement require a skills test?
A: No. The HazMat endorsement does not require a CDL skills test. However, first-time HazMat applicants must complete FMCSA-required ELDT HazMat theory training before taking the state knowledge test.
Q: How often do I need to renew my Hazmat endorsement?
A: The Hazmat endorsement must be renewed every 5 years. Renewal requires submitting a new TSA Security Threat Assessment, including fingerprinting.
Q: Do I need to be a U.S. citizen to get a Hazmat endorsement?
A: No. Both U.S. citizens and qualifying non-citizen lawful permanent residents (Green Card holders) are eligible to apply for the TSA Security Threat Assessment and obtain the H Endorsement.
Content Accuracy & Sources
References: This page and its practice questions are based on the Federal Motor Carrier Safety Administration (FMCSA) CDL Handbook, Title 49 of the Code of Federal Regulations (49 CFR) Hazardous Materials Regulations, and official state DMV CDL Handbooks.
Reviewed by: DriveTestUSA CDL Research Team