Which gases have a smell?

Answer 1

Many gases have a smell with just a few having no smell at all. The commonest are: Without a smell: Nitrogen, Hydrogen, Helium, Neon, Argon, Krypton, Xenon, Radon, Carbon dioxide, Carbon Monoxide, Methane With a smell:Fluorine - harsh and biting Chlorine - harsh and biting and like bleach Ammonia - harsh and choking - Sulphur Dioxide - Harsh, acidic and biting Nitrous Oxide - rather sweet and sickly Nitrogen Dioxide - Bleachy and harsh Pure oxygen - very slightly sweet Hydrogen sulphide - like rotten eggs There are many others but these give some idea. Incidentally, the smell associated with household gas used as a fuel is actually added, as methane (which makes up most of the gas) has no smell. The addition of a smell is a safety feature so that leaks can be detected quickly.