What we normally think of as “natural gas” consists mainly of methane with smaller amounts of other compounds and elements. Methane is the simplest of a large family of carbon and hydrogen compounds, called hydrocarbons. Hydrocarbons also include, among other things, propane used in gas grills, butane used in disposable lighters, and crude oil. Methane is highly flammable. It is also odorless and tasteless. Some natural gases have strong odors – they smell like a refinery or rotten eggs because they contain more than just methane. The strong odor typically associated with the natural gas we use in our houses comes from a chemical mercaptin that the gas company adds before the gas is sent through pipelines.