That sulfuric, rotten egg odor that signals a natural gas leak isn't an ordinary component of the carbon-hydrogen compound. Because of the potential danger associated with natural gas leaks, suppliers add the noxious scent to natural gas as an olfactory warning that the harmful vapors are loose in the air.
This precautionary measure indicates the inherent hazards of natural gas that can, at the right levels, kill you. That said, natural gas is repeatedly touted as one of the safest and cleanest-burning fossil fuel sources. More than 65 million homes in the United States use it to power their gas stoves, water heaters and other essential appliances [source: Safe Gas Indiana]. When correctly burned, natural gas produces mostly water vapor and carbon dioxide and far fewer greenhouse emissions than wood, coal and oil [source: Alberta Energy].
Natural gas has become a widespread energy source because it's highly combustible, which means that it can produce large amounts of heat when you burn small amounts. Consequently, a natural gas leak can increase the risk of fire and explosion since it spreads quickly and combusts easily. An electrical spark or fire source can set this off if you have a leak in your house.
If you suspect a natural gas leak inside, immediately stop what you're doing (do not flip any electrical switches, unplug anything or use a telephone) and go outside. Inhaling high concentrations can also lead to asphyxia (when the body is deprived of oxygen) and possibly death. Early symptoms of asphyxia include fatigue and chest pain.
Although generally safe to use in the home, when natural gas does not burn up completely because of faulty installation or lack of ventilation, it emits a byproduct of carbon monoxide. The more carbon monoxide present in the air, the less oxygen you can inhale, potentially killing you. In fact, 500 people in the United States die of unintentional carbon monoxide poisoning every year [source: Centers for Disease Control and Prevention].
What if you have a cold or a poor sense of smell? Is there any way to detect a natural gas leak besides that signature scent? Find out on the next page.