Allyl methyl sulphide

Rotten eggs, farts and bad breath – nasty smells come in many different forms. These stinky substances often contain sulphur compounds. Your nose can detect them even in very low concentrations, for example, the odour that is added to natural gas and which gives petrol pumps their typical smell. Many sulphur compounds have a low boiling point, which also makes them gaseous at low temperatures. In our relatively warm bodies, they are then released in intestinal gases and in our breath.

Allyl methyl sulphide is the substance you can smell on someone who has eaten garlic. Garlic contains allicine, a sulphur compound that protects the plant against pests and diseases. Your body converts allicine into allyl methyl sulphide, which is also released through your breath and – if you eat garlic often enough – your sweat.