Mercaptan is a group of compounds, more than one of which are used as gas odorants, so in some places, gas smells of rotten eggs, similar to H2S, while in other

Mercaptan is a group of compounds, more than one of which are used as gas odorants, so in some places, gas smells of rotten eggs, similar to H2S, while in others gas doesn't smell like that at all, but a quite distinct smell that's reminiscent garlic and durian.