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What Does a Gas Leak Smell Like?

In this article, we’ve compiled important information on how to identify, respond to, and prevent natural gas leaks.

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Natural gas is one of the cleanest and safest fossil fuels used within the home, powering gas appliances and systems such as the stove and water heater. Since natural gas is odorless and tasteless, a harmless substance called mercaptan is added into it so that a leak can be detected. Unlike smoke or carbon monoxide that relies on alarms to detect the presence of gas or smoke, a natural gas leak is detected through sights, sounds, and smells.

Identifying a Natural Gas Leak

Although natural gas isn’t toxic, a leak increases the risk of fire or combustion, making it important to identify the gas and find the source so that the appropriate safety precautions are followed.

Rotten Egg Smell

Mercaptan is an additive in natural gas that produces an odor similar to rotten eggs or cabbage. If you smell this odor in the home, you could have a natural gas leak. If a faint, similar smell is coming from the bathroom, you could have a different problem.

Sewer gas can leak into your home through a broken toilet seal or unused drain pipe. To diagnose a sewer gas issue in the bathroom, contact a plumber.

Continuous Bubbling in Standing Water

If standing water outside your home is bubbling, there could be a leak in your outdoor gas line. This is the effect of water dissolving the leaking natural gas, resulting in visible bubbles.

Roaring or Hissing Sound

Natural gas can softly hiss or roar as it escapes from a leaking pipe. Usually, the source of the leak is the natural gas connection at the back of an appliance, in which case you’ll most likely be able to smell the gas leaking indoors.

Dead Plants

If there’s a leak in the outside gas line leading to your home, dead or dying plants could signal an issue. When natural gas leaks into your lawn, it displaces the oxygen necessary for the plant’s roots to survive. If you notice dead plants in your yard despite proper gardening care, you could have a natural gas leak.

Unnatural Dirt and Air Movement

The pressure released by a leak in your natural gas line can cause an unusual amount of air to blow across your yard. If there isn’t a noticeable natural breeze and you see dirt blowing out of your yard or air blowing across plants, you could have a natural gas leak.

Health Effects

Though natural gas is non-toxic, prolonged exposure to its properties can cause a noticeable decline in health. As natural gas continuously leaks into your home, it can affect your sense of smell and displace oxygen, causing breathing difficulties, headaches, and nausea. If you’re experiencing these symptoms and aren’t suffering from a separate illness or underlying condition, there’s a possibility you have a gas leak.

What to Do If You Smell Natural Gas

If you think you’re experiencing a gas leak, follow these steps:

  1. Exit the area immediately—If the smell of natural gas is mild, open the windows of your home, turn off the pilot light in your fireplace or water heater, and leave the house and surrounding area. If there’s a severe gas leak causing an overpowering smell or symptoms like nausea and headaches, exit your home and leave the area immediately.
  2. Call the gas company and emergency services—Once the signs of a natural gas leak are detected and you’re safely away from your home and yard, contact the proper authorities to confirm and fix the leak. Contact your local natural gas supplier or call 911.
  3. Never use your phone or other electronics near a suspected leak—If you suspect a gas leak in your home, wait until outside and at a safe distance from your home to use your phone to call your gas service or 911. Electronics create static electricity that’s capable of igniting the highly flammable natural gas that’s leaked into the air.

Read More: Staying Safe with Natural Gas

How to Prevent Natural Gas Leaks

Although you can’t always stop a natural gas leak, there are some precautions you can take to minimize the risk of a leak.

  • Regularly service your systems and appliances, checking them for wear and tear that can lead to a gas leak.
  • Have your appliances and pipelines professionally inspected at least once a year to confirm there are no leaks.
  • Contact a professional to have your gas fittings and shut-off valves replaced. This will prevent the old infrastructure from corroding and causing a leak.

Frequently Asked Questions About Gas Leaks

What does a gas leak smell like in your house?

Natural gas is odorless, but a substance known as mercaptan is added to your natural gas so that it gives off a pungent rotten egg smell. If you notice this odor in your home, it’s possible you have a natural gas leak.

Who pays for a gas leak?

It’s often misunderstood that utility companies pay for the repair of a leak in a gas line. You are responsible for paying for the repair and damages caused by gas appliances or lights leaking. Thankfully, some home warranty companies, such as American Home Shield, cover leaks and breaks in gas lines.

What should you do if you smell gas?

If you suspect a natural gas leak and smell something similar to rotten eggs, open the doors and windows, turn off any pilot lights, exit your home, and contact 911 or your gas provider. For more severe leaks, leave the property immediately before contacting the appropriate authorities.

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