Home › Practice › Hazardous Materials (Hazmat) › Question 23

Hazardous Materials (Hazmat) Practice Question 23

H or XHazardous Materials (Hazmat) · Question 23

Class 9 hazardous materials are:

• AMiscellaneous (e.g., elevated temperature, marine pollutants, lithium batteries)
• BExplosives
• CGases
• DToxic

Correct answer: A. Miscellaneous (e.g., elevated temperature, marine pollutants, lithium batteries)

Why: Class 9 is the catch-all for materials that pose a hazard during transport but do not fit cleanly into Classes 1-8.

How this question fits the Hazmat test

Mishandled hazmat causes catastrophic public consequences. The endorsement is restricted, requires fingerprint background screening through the TSA, and demands deeper familiarity with regulatory paperwork than any other CDL endorsement.

Study technique for this topic

Master the Hazardous Materials Table columns, know the placarding thresholds, and learn which classes can never be loaded together. Practice locating UN/NA identification numbers and understanding the segregation chart.

Related Hazmat practice questions

• Q29. A 'cargo tank' is:
• Q42. Hazmat tanker drivers must check tank closures (manhole covers, valves):
• Q55. The 'Hazardous Substances' RQ values are listed in:
• Q4. For most hazardous materials, placarding is required when:
• Q17. Class 3 hazardous materials are:

Continue your CDL preparation

The Hazardous Materials (Hazmat) portion of the CDL knowledge exam covers more than this single question. Use this site's full Hazardous Materials (Hazmat) bank to drill every topic, then test yourself with one of our state-specific practice sets to confirm you are ready for the actual DMV exam in your state. Always check your state's CDL handbook for any local addenda before the test day.

If you are still building your overall CDL foundation, start with the General Knowledge bank — every CDL applicant must pass it — and then work outward to the endorsements you plan to add.