Question A tank endorsement is: Answers Only required when transporting gases. Only required when transporting liquids. Used when transporting both liquids and gases. Optional when transporting hazardous materials. Explanation In general, a tank endorsement is required to a drive tank vehicle used to transport liquids or gases. This applies to both hazardous and non-hazardous materials. Take a FREE Practice Test Now This questions appears in the following tests: Colorado Knowledge Test Class A , Georgia Knowledge Test Class A , Kansas Double , Massachusetts Air Brakes , West Virginia Air Brakes , Wisconsin Air Brakes ,