If I have a gas leak in my home, will I die?

holding nose about gas leak — There's a reason a natural gas leak has a rotten egg odor. That stink is meant to signal danger. Any spark — a match or even a light switch — could cause a serious explosion. David De Lossy/Getty Images

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. 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. At least 430 people in the United States die of unintentional carbon monoxide poisoning every year. And 50,000 people visit the ER for accidental carbon monoxide poisoning annually [source: CDC]. Unvented space heaters are the most common source of carbon monoxide poisoning [source: Johns Hopkins Medicine]. But fumes are also produced by furnaces, stoves, kerosene heaters and vehicles "warmed up" in garages.

That said, natural gas is considered one of the safest and cleanest-burning fossil fuel sources. When correctly burned, natural gas produces mostly water vapor and carbon dioxide and fewer greenhouse emissions than wood, coal and oil, making it a relatively clean fuel [source: EIA]. About half the homes in the United States use gas for heating and cooking [source: EIA].

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. Go outside. Then call your gas company, so they can send someone to inspect your home.

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?

Gas Leak Detectors

Natural gas occurs in its rawest state as a colorless, odorless gas formed over millions of years within the earth. It has resulted from millenniums of compression of decomposing organic materials in the same way that other fossil fuels were created. Consumers access natural gas through millions of miles of pipelines that extract the hydrocarbons from their earthen reservoirs, remove impurities and transport it as mostly methane gas [source: EIA].

If you have a gas stove, there are about 5 to 15 parts per million of natural gas in the air inside your home. More than 30 parts per million crosses into dangerous levels of natural gas and indicates a faulty stove [source: EPA]. How do you know if the methane levels in your house are safe? You can buy a natural gas detector or a carbon monoxide detector that will sound an alarm if gas levels exceed a safety threshold.

We use methane in gas stoves, heaters, water heaters and ovens. The risk of carbon monoxide poisoning from methane peaks during the winter because we heat our homes. Often, houses aren't ventilated in the winter to retain that heat. To avoid carbon monoxide poisoning, particularly in the wintertime, you can install a carbon monoxide detector. Like most of these devices, an alarm will sound if the air contains a high level of the gas.

Other signs of gas leaks are [source: Constellation Energy Resources]:

a hissing sound near your gas line or appliance
dying plants in your home
air bubbles in standing water outside your home
physical symptoms, like nausea, fatigue, headaches
an unusually high gas bill

While natural gas used indoors can pose health risks, the greatest chance for a natural gas leak happens outdoors. Since more than 2 million miles (3.2 million kilometers) of natural gas pipeline funnels the fuel underground in the United States, you must take caution when digging in your yard. Signs of a broken natural gas pipe include dirt blowing up from the ground on a windless day, a hissing sound or bubbling water.

If you plan to do any deep digging around your house, call 811 for the national Underground Service Alert network a few business days before digging. The free service will map out any utilities, including gas pipelines, buried beneath your land. Striking a pipeline can endanger your life since the gas is highly explosive and could disrupt natural gas service to surrounding homes. Natural gas pipeline leaks and explosions cause about 17 deaths in the U.S. every year [source: Jackson et al.].

Gas Leak FAQ

What does a gas leak smell like?

Natural gas has a rotten, sulfuric odor that alerts homeowners about the possibility of a natural gas leak. This smell is intentionally added to serve as a warning.

What should you do if you smell gas?

If you suspect thereâ€™s a gas leak in your home, stop whatever you are doing and go outside. If you inhale it in higher amounts, it can cause asphyxia, which can occasionally lead to death.

Is a small gas leak dangerous?

Yes, it is. A small gas leak can still catch on fire and trigger an explosion from another fire source or electrical spark.

What happens if gas leaks from stove?

A stove leak is more dangerous than you might think. If you suspect one, avoid touching the appliances or turning them on. Vacate your home and call for help.

Can you get sick from a natural gas leak?

Being exposed to a gas leak for a long time can cause a number of symptoms, including headaches, nausea and weakness. If you feel abnormal or sick, call an ambulance immediately.

Lots More Information

Sources

Centers for Disease Control and Prevention. "Carbon Monoxide Poisoning Prevention". (June 14, 2022) https://www.cdc.gov/nceh/features/copoisoning/index.html
Constellation Energy Resources. "Natural Gas Safety Tips for Your Home." (June 14, 2022) https://www.constellation.com/energy-101/home-natural-gas-safety-tips.html
Jackson, Robert et al. "Natural Gas Pipeline Leaks Across Washington, DC." Environ. Sci. Technol. Jan. 16, 2014 (June 14, 2022) https://pubs.acs.org/doi/abs/10.1021/es404474x
Johns Hopkins Medicine. "What is carbon monoxide poisoning?" (June 14, 2022) https://www.hopkinsmedicine.org/health/conditions-and-diseases/carbon-monoxide-poisoning
U.S. Energy Information Administration (EIA). "Natural Gas Explained." (June 14, 2022) https://www.eia.gov/energyexplained/natural-gas/
U.S. Environmental Protection Agency. "What is the average level of carbon monoxide in homes?" (June 14, 2022). https://www.epa.gov/indoor-air-quality-iaq/what-average-level-carbon-monoxide-homes

If I Have a Gas Leak in My Home, Will I Die?