Alcohol is widely consumed as a beverage and governments view this product as a source of revenue and therefore levy an excise duty on it. It follows that strict control has to be exercised on the product, both in the distilleries and during its distribution thereafter.
Other uses of alcohol far outweigh its use for potable consumption, but these applications cannot bear the cost of the excise duty. There thus exists a process in legislation whereby the alcohol can be denatured (rendered non-potable) according to a registered formula, by the addition of chemicals. These chemicals (denaturants) prevent separation of the alcohol by physical means and are very bitter or even poisonous in the long term. Once denatured, the alcohol does not attract excise duty, though administrative control is sometimes exercised over the product, depending on the degree of denaturing. This distinction is referred to as partial or full denaturing.