Isopropyl mercaptan is a thiol with the formula C<sub>3</sub>H<sub>8</sub>S. It is a water-white liquid with an extremely pungent odor resembling skunk spray or rotten eggs. The pungent smell allows it to be used as an odorizer. The FDA has approved it for use as a food additive for its flavor. Another use is as a rubber additive.