Isobutyl nitrite, C<sub>4</sub>H<sub>9</sub>NO<sub>2</sub>, is an alkyl nitrite, an ester of isobutanol and nitrous acid. Its chemical structure is (CH<sub>3</sub>)<sub>2</sub>CH-CH<sub>2</sub>-ONO.
Isobutyl nitrite is a pungent colorless liquid. It acts as a vasodilator, and is used as an inhalant recreational drug, poppers.
Isobutyl nitrite is one of the compounds used as poppers, an inhalant drug that induces a brief euphoria. Also, it is used as part of the antidote package for cyanide poisoning.
May cause headaches, dizziness and fainting. Isobutyl nitrite is poisonous to people with glucose-6-phosphate dehydrogenase deficiency.