Denatured Alcohol: to Prevent Theft for Human Consumption

Denatured alcohol is used as a solvent and as fuel for spirit burners and camping stoves. Because of the diversity of industrial uses for denatured alcohol, hundreds of additives and denaturing methods have been used. Traditionally, the main additive is 10% methanol, giving rise to the term spirit. In denaturing alcohol the ethanol molecule is not chemically altered, only the liquid's digestion and intake is affected.

Denatured alcohol is not, in itself, a preferred product - that is, it is not something which would be normally demanded if given the alternative of normal ethanol. Denatured alcohol and its manufacture are a public policy compromise. The supply and demand for denatured alcohol arises from the fact that normal alcohol (specifically ethanol, suitable for human consumption as a drink) is usually very expensive compared to similar chemicals, being highly taxed for revenue and public health policy purposes (see sin tax).

As a result, if pure ethanol were made cheaply available for other useful industrial and commercial purposes (such as fuel or solvents) this would create a temptation or incentive to convert relatively cheap industrial ethanol for human consumption.

Despite its poisonous nature, denatured alcohol is sometimes consumed as a surrogate alcohol, which can result in blindness or death if denatured alcohol contains methanol.

To help prevent this, some other chemical is often added to give the substance an extremely bitter flavor. Substances such as pyridine help to give the mixture an unpleasant odor, and vomiting agents such as vomiting syrup may also be included to finally prevent theft for human consumption.