A chemical tanker is a type of tanker designed to transport chemicals in bulk. As defined in MARPOL Annex II chemical tanker means a ship constructed or adapted for the carriage in bulk of any liquid product listed in chapter 17 of the International Bulk Chemical Code. Ocean-going chemical tankers generally range from 5,000 metric tons deadweight (DWT) to 40,000 DWT in size, which is considerably smaller than the average size of other tanker types due to the specialised nature of their cargoes and the size restrictions of the port terminals where they call to load and discharge.
Chemical tankers normally have a series of separate cargo tanks which are either coated with specialised coatings such as phenolic epoxy or zinc paint, or made from stainless steel. The coating or cargo tank material determines what types of cargo a particular tank can carry: stainless steel tanks are required for aggressive acid cargoes such as sulfuric and phosphoric acid, while ‘easier’ cargoes — such as vegetable oil — can be carried in epoxy coated tanks.
