Misc Musings

You Can’t Smell Gas


Natural Gas is odorless. It is comprised mainly of methane which does not smell, however when you turn on the gas on your stove it gives off a very strong stench!

This is because of a chemical known as Mercaptan (also known as Thiol). This is added to Natural gas in order to make it smell! It is a harmless gas which is a waste product of normal metabolism and is found naturally in living organisms.

The chemical features very few useful qualities, bar one, it gives off an incredibly pungent smell. Even in the smallest quantities the human nose can still detect it. It is the world’s smelliest substance and is unbearable in its concentrated form.

Mercaptan has been added into natural gas supplies in order to be able to detect it quickly should there be any kind of leak.  Natural Gas is a very dangerous substance as it contains carbon monoxide, breathing in this chemical can cut off the oxygen supply to the brain, which can be fatal in prolonged doses. Natural gas is also an incredibly flammable substance and if allowed to build up and reach a source of ignition can easily start fires.

The first instance of odorized gas was in Germany during the 1880s in order to make it detectable however Mercaptan wasn’t implemented universally until the 1937 New London Texas School explosion. Natural gas leaked into the crawl spaces of the school, undetected, until it eventually ignited destroying the building and killing 295 people. As a result regulations have been introduced worldwide to ensure odorization of natural gas.

So when you think you are smelling gas, you actually aren’t. It’s Mercaptan.

Bonus Fact:

  • The same chemical that makes gas smell is present in Asparagus and gives your urine a noticeably strong smell within 30 minutes of eating it.
  • The chemical Mercaptan is also present in Skunks spray, and it what gives them their distinctive smelly defence mechansism.


Further reading

1 thought on “You Can’t Smell Gas”

Leave a Reply

Your email address will not be published. Required fields are marked *