Gas Safety

Smell Gas. Act Fast.
Gas leaks can create fires and explosions. It's important that you and your family know how to recognize a gas leak and what to do if you suspect a leak.

How to Recognize a Gas Leak

Smell—A distinctive, strong odor similar to rotten eggs
See—A white cloud, mist, fog, bubbles in standing water, blowing dust, or vegetation that appears to be dead or dying for no reason
Hear—Roaring, hissing, or whistling

Why Natural Gas Smells Like Rotten Eggs

Natural gas doesn’t actually smell like anything. That’s why we add a chemical called methyl mercaptan (methanethiol) to natural gas so you’ll be able to smell it in case of a leak. Mercaptan has a very distinct and unpleasant odor that many people compare to the smell of rotten eggs. 

What to Do If You Think There Is a Gas Leak

  • If the odor is strong, leave immediately and take others with you.
  • If you are outside, leave the area immediately.
  • Don’t light a match or smoke, turn appliances or lights on or off (including flashlights), use a telephone, or start a car. Doing so can produce sparks that might cause the gas to explode.
  • Find a phone away from the area and call 911 or 1-800-75-CONED (1-800-752-6633). You can report leaks anonymously.
  • Don’t assume someone else will report it.
  • National Grid customers should call 1-718-643-4050.
  • Follow directions from emergency responders who are on site.

Gas Leak FAQ

Call 811 Before You Dig

Watch a video to learn how to recognize gas leaks.

Excess Flow Valves

Your natural gas service is safe, clean, and reliable. But if a contractor excavating on your property accidentally damages your gas pipeline, it could cause a gas leak. To avoid this, please insist that any workers (including yourself) digging around your home or business call 811 before excavating so we can make sure they’re digging safely.

As an optional added safety measure to protect your property from a gas leak resulting from excavation damage, you can request to have an “excess flow valve” installed, at your expense, between the street and your meter. This mechanical safety device will automatically shut off the flow of gas if your service line breaks. This can reduce the risk of fire, explosion, and injury if the line is damaged, but it won’t automatically shut off the gas if there is a small leak.

To install the valve, we must excavate the service line where it connects to the gas mainline piping that runs down your street. We will then turn off your gas, install the valve, backfill the excavation and relight your appliances. The approximate cost to install this optional feature is $4,000 for a recently installed service, or $25,000 for an older service. This cost may vary based on your location. There will be no additional costs to maintain or replace the device.

Excess flow valves are installed only on service lines that operate at pressures of 10 psig or greater and for loads of 1,000 standard cubic feet per hour or less. Other exceptions may apply. To learn more, to find out if your gas service is eligible for this equipment, or to schedule an installation date that works for you and us, please login to Project Center and create a new request.