Essential oil
Because it may contain erucic acid, a potential toxin, mustard oil is restricted from import as a vegetable oil into the United States. Essential oil of mustard, however, is accepted as GRAS (Generally Recognized as Safe). But in Russia, this is the main species grown for the production of mustard oil. It is widely used in canning, baking and margarine production in Russia, and the majority of Russian table mustard is also made from "B. juncea".