What Gives Natural Gas Its Odour?

What Gives Natural Gas Its Odour?


Mercaptan is not the most pleasant smelling thing in the world but as North Shore gas fitters with your safety as our highest priority, we think it is one of the most important.

Mercaptan is the strong-smelling gas added to odourless natural gas. By doing this, it makes it easier to detect a gas leak and this can be a lifesaver. It was first added to natural gas in 1937, after an undetectable gas leak at a school in New London, Texas caused an explosion which killed 300 students and teachers. This catastrophe occurred because no one had any clue that natural gas was leaking and building up with such potentially dire consequences.  Without mercaptan, there was absolutely nothing to alert those at the school that something was amiss,

Mercaptan is found naturally in living organisms, including the human body and is a waste product of metabolism.  It consists of sulphur, carbon and hydrogen, and this combination – particularly sulphur – is responsible for that unmistakable odour which many people liken to over-cooked cabbage, flatulence or rotten eggs. It is such a potent odour that it can be detected by most people in tiny quantities i.e. less than one part per million. So, thankfully, not too much is required to make us aware when there is a gas leak. In these limited quantities, the smell is certainly noticeable but not overbearing.

Another of mercaptan’s properties which makes it such a valuable additive to natural gas is that it is flammable. This means the combustion efficiency of natural gas when cooking, heating the home, or providing hot water is not compromised at all.

While you might be only too aware of the odour of natural gas and can act accordingly in case of a leak, your young family might not. They might just think that someone has overcooked the cabbage again! On a serious note, we believe it is important to teach your kids to be aware of the particular odour of mercaptan-enriched natural gas and to alert you should they get a whiff of it. It could be a sign of a faulty and dangerous leak in one of your gas appliances and you need to shut it off, or the mains gas supply itself.

We think another wise idea is to ask us to perform a regular check of all your gas appliances and fittings, as ongoing maintenance will reduce the risk of a leak. Contact us today – we’re North Shore gas fitters who, like mercaptan, pass the sniff test!