The boiling point of soybean oil, the most common cooking oil typically marketed as vegetable oil, is approximately 300 degrees Celsius. Other cooking oils have similar boiling points.
It is difficult to determine the boiling point of a cooking oil because most oils never reach a boil in a home environment. Cooking oils have smoke points that are much lower than their boiling points. When an oil reaches its smoke point, it starts to break down, which creates smoke and gives food an unpleasant, burnt taste. Oils require high heat to boil because they are composed of large molecules that bond tightly to each other. Much heat is required before the bonds break and boiling occurs.