Question A tank endorsement is: Answers Only required when transporting gases. Only required when transporting liquids. Required when transporting both liquids and gases. Optional when transporting hazardous materials. Explanation With some exceptions, you must have a tank endorsement to transport liquids or gases. This applies to both hazardous and non-hazardous substances. Take a FREE Practice Test Now This questions appears in the following tests: New Jersey Knowledge Test Class A , Nebraska Air Brakes , New Hampshire Air Brakes ,