Natural gas is both odorless and colorless, so Dominion adds
an ingredient called mercaptan to it so you can detect its presence. If we did
not add mercaptan, it would be hard for you to know that unlit natural gas was
coming from your stove after you left the valve turned on. And leaks from furnaces
and hot water heaters would be nearly impossible to detect without expensive
equipment. So mercaptan’s smell is a very valuable safety feature.
But one thing's clear -- mercaptan stinks. In a concentrated
form, its smell is almost unbearable. And it takes only a few parts per million
of mercaptan for the average person to wrinkle a nose and say, “What is
that smell?”
Mercaptans contain sulfur. That’s what makes them smell.
The kind we use blends well with natural gas and, in a gaseous state, has much
the same properties as natural gas, so it will also rise and dissipate with
natural gas.
There are other uses for mercaptans in industry, including
jet fuel, pharmaceuticals and livestock feed additives. They are used in many
chemical plants. Mercaptans are less corrosive and less toxic than similar sulfur
compounds found naturally in rotten eggs, onions, garlic, skunks, and, of course,
bad breath. You know, things that stink.
