The denatured alchol is Ethyl alcohol (ethanol or CH3CH2OH) made undrinkable by the addition of very bad-tasting chemicals (denaturants) which usually also have offensive odor, such as gasoline, kerosene, methanol etc.The objective of denaturing is to escape the excise duty levied on drinkable ethanol because after adding those chemcals it is no more a drinkble liquid.