What Does a Gas Leak Smell Like?

If you have natural gas in your home, be sure you know how to detect a leak and what to do in case such an emergency occurs.

Nearly 187 million Americans use natural gas to heat their homes and water and cook their food, according to the American Gas Association. It’s an affordable, reliable and safe energy source when used properly.

However, it’s also colorless, odorless and tasteless, and produces carbon monoxide when burned incompletely. Exposure to carbon monoxide can cause headaches, fatigue, nausea, chest pain, confusion/poor judgment/memory loss and even death. About 4,200 home fires start each year when natural gas ignites, according to the National Fire Protection Association.

To avoid a dangerous situation in your home, learn how to detect a gas leak and what actions to take.

Fortunately, there are some key indicators of a gas leak. If you hear hissing, see air bubbles in standing water, notice dead, dying, or stunted plants inside or outside your home or have higher than normal natural gas bills, there could be a leak. But the most common warning sign is the distinctive odor associated with a gas leak.

What Does a Gas Leak Smell Like?

It’s often described as rotten eggs, sulfur-like or skunk-like. That’s because the federal government mandates utilities to add a chemical (typically mercaptan or methanethiol) to natural gas, a process called odorization.

According to Gary Worland of Natural Gas Specialists, “Because natural gas is odorless, there are various types of odorants that a utility will inject into their distribution system to ensure the gas has a `skunk-like’ smell to it to alert the public. It ensures the gas is readily detectable by a person with a normal sense of smell.”

To stay safe, it’s important to recognize the smell in your own home. The smell can vary depending on utility and region.

“Each utility adds different types of odorants to natural gas,” Worland says. “It’s more specific to the region with regard to what the odor smells like.” Utilities are required to educate customers about natural gas safety, including what their specific gas smells like. Visit your local utility’s website to learn more.

If you’re curious, there are a couple of ways to safely take a whiff. Be sure to do it through your utility.

“Some utilities utilize their customers to verify that their gas is detectable by smell while the technician conducts a routine service call,” says Worland.

“For example, a utility technician is dispatched to a home. After conducting their utility-specific procedures, the gas tech may call the customer over to the gas stove and briefly turn the stove burner to the ON position, allowing a small amount of unlit gas through the burner, then shut the burner off and have the customer comment on whether they smelled the odorant.”

Another way is to get a natural gas scratch-and-sniff card. Be sure to use the card outdoors because the odor tends to linger inside, possibly triggering an unnecessary emergency gas leak call. Although utilities used to mail these out to their customers for educational purposes, they no longer do so because of the risk of false alarms.

What To Do if You Smell Gas

If you smell gas, take action immediately. If there are any open flames, put them out right away. Then get out of your house immediately.

Once everyone has vacated the building and is safely away from the area, the American Gas Association says to call 911 and/or your natural gas utility to report the smell. Follow the directions provided by utility employees and emergency responders.

It’s also smart to know how to shut off natural gas in your home, according to Constellation Energy. Shutoff valves are usually outside of the home. Cutting off the supply prevents additional gas from escaping. If you’re comfortable, shut off the gas. But it’s still critical to exit your home and call for help.

Make sure everyone knows what to do in case of a natural gas emergency, including children. View this educational video from the American Gas Association to familiarize the whole family with natural gas safety.

What NOT to Do if You Smell Gas

While there are certain actions to take if you smell a gas leak, the following should be avoided to stay safe.


  • Smoke or strike any matches;
  • Light any candles;
  • Flip light switches on or off;
  • Use a telephone;
  • Operate any electrical equipment that could create a spark, like a cell phone;
  • Use the doorbell;
  • Adjust thermostats or appliance controls;
  • Use elevators;
  • Position or operate power equipment in the area;
  • Start a car;
  • Try to locate the source of the leak yourself;
  • Try to stop the leak yourself;
  • Go back inside your home before the gas company says it’s safe;
  • Turn the gas back on yourself.

Most importantly, never try to repair the leak yourself. Your local gas company most likely provides 24/7 emergency service and will immediately respond at no charge. All repairs to gas lines must be made in accordance with local regulations by a licensed professional.

And be sure to install natural gas and carbon monoxide detectors in your home, so you’ll be warned if there’s a buildup of either potential threat.

Sandi Schwartz
Sandi Schwartz is a multi-award-winning author of the book "Finding Ecohappiness: Fun Nature Activities to Help Your Kids Feel Happier and Calmer" and a freelance journalist specializing in sustainability, home and garden, green living, nature, and wellness. Her work has been featured in The Washington Post, National Geographic, Yahoo!, BobVila.com, Earth911, mindbodygreen, Verywell, and many more publications. She enjoys relaxing walks and bike rides, nature art, and her new meditation garden.