Imports In 2018, British Indian Ocean Territory imported $785 in Sodium hydroxide (caustic soda) solid, becoming the 0th largest importer of Sodium hydroxide (caustic soda) solid in the world. At the same year, Sodium hydroxide (caustic soda) solid was the 0th most imported product in British Indian Ocean Territory. British Indian Ocean Territory imports Sodium hydroxide (caustic soda) solid primarily from: N/A.