Denatured alcohol, also known as methylated spirits, metho, or meths in Australia, Ireland, New Zealand, South Africa, and the United Kingdom, and as denatured rectified spirit, is ethanol that has additives to make it poisonous, bad-tasting, foul-smelling, or nauseating to discourage its recreational consumption. It is sometimes dyed so that it can be identified visually. Pyridine and methanol, each and together, make denatured alcohol poisonous; denatonium makes it bitter.
Denatured alcohol is used as a solvent and as fuel for alcohol burners and camping stoves. Because of the diversity of industrial uses for denatured alcohol, hundreds of additives and denaturing methods have been used. The main additive usually is 10% methanol (methyl alcohol), hence the name methylated spirits. Other common additives include isopropyl alcohol, acetone, methyl ethyl ketone, and methyl isobutyl ketone.