Mineral oil (also known as white mineral oil) is used in the food world for stuff like covering gummy bears so they don’t stick together, providing a nonstick coating for baked goods, and adding a protective layer to raw fruits and vegetables. Around the house, it’s most commonly used to oil cutting boards so they don’t crack, and is sometimes used as a laxative.
It is a petroleum product that starts life as crude oil, which is then hyperrefined to remove any odor, color, or taste. White mineral oil is classified as either food grade or technical grade. The differences between the two include things like the level of refinement, handling procedures, and meeting certain test requirements set out by the U.S. Pharmacopeia.
“When you say that [it’s a petroleum product] people are like, ‘Oh my God,’” says David Glickman, the owner of the Vermont Butcher Block and Board Company. But he says it’s the best oil to use on cutting boards because it imparts no odor and won’t go rancid like vegetable oils will. If the idea of using a petroleum product on your cutting board doesn’t sit well with you, Glickman says that nut oils will also do the job (as long as you don’t have allergies) but adds that these can flavor the food you cut on the board.