what’s that smell?

The facts about methyl mercaptan (methanethiol)

Natural gas for delivery to end-users is odorless. Mercaptan is a chemical that is added to natural gas to make it easier to detect in case of a leak. Mercaptan has a very distinct and unpleasant odor that is produced by sulfur – many people compare the smell of Mercaptan to rotten eggs. Mercaptan is added to natural gas so that customers will know that unlit natural gas is leaking from a stove, furnace, water heater, or other gas-fueled appliance. There are other uses for mercaptans in industry, including jet fuel, pharmaceuticals, and livestock feed additives.

If you smell a gas odor, you should move to a safe environment and call Con Edison immediately at 1-800-75-CONED (1-800-752-6633). Don't assume that someone else will report the condition. Don't smoke or operate electrical switches or appliances because they may produce a spark that might ignite the gas.