The Ethyl Mercaptan (EM) is a key raw material for agrochemical synthesis. EM is also a gas odorant used worldwide to odorize LPG. Ethyl Mercaptan is a colourless or yellowish liquid or a gas with a pungent, garlic or skunk-like odour. It is used as an additive to odourless gases like butane, propane, and petroleum to give them a warning odour.