Food is deliberately denatured when a substance, known as a denaturant, is added to render the food unpleasant to consume or poisonous. Aversive agents—primarily bitterants and pungent agents—are used to produce an unpleasant flavor. For example, the bitterant denatonium might be added to food used in the laboratory, where the food is not intended for human consumption. A poison may be added as an even more powerful deterrent. For example, methanol is added to ethanol to produce denatured alcohol. The addition of poisonous methanol renders denatured alcohol unfit for consumption. Thus denatured alcohol is not subject to the taxes alcoholic beverages are subject to.