Methyl mercaptan is a colorless gas with a smell like rotten cabbage. It is a natural substance found in the blood, brain, and other tissues of people and animals. It is released from animal feces. It occurs naturally in certain foods, such as some nuts and cheese.
In its native state, natural gas is odorless, colorless and tasteless. Mercaptan, the harmless chemical that is added to natural gas, contains sulfur, which makes it smell. Many people describe the odor of mercaptan as similar to rotten eggs.
