If you carry 1000 gallons of liquids or roughly 8000 lb, you need Tanker Endorsement.

On May 9, 2011, FMCSA revised the definition of “tank vehicle” to include any commercial motor vehicle that is designed to transport any liquid or gaseous materials within a tank or tanks having an individual rated capacity of more than 119 gallons and an aggregate rated capacity of 1,000 gallons or more that is either permanently or temporarily attached to the vehicle or the chassis. Does the new definition include loaded intermediate bulk containers (IBCs) or other tanks temporarily attached to a CMV?

Guidance:

Yes. The new definition is intended to cover (1) a vehicle transporting an IBC or other tank used for any liquid or gaseous materials, with an individual rated capacity of 1,000 gallons or more that is either permanently or temporarily attached to the vehicle or chassis; or (2) a vehicle used to transport multiple IBCs or other tanks having an individual rated capacity of more than 119 gallons and an aggregate rated capacity of 1,000 gallons or more that are permanently or temporarily attached to the vehicle or the chassis.