Natural Gas Leaks, Odors or Emergencies

Emergency Information

En Español

If you have a natural gas emergency, call Nicor Gas at
1-888-Nicor4u (1-888-642-6748)
We're available 24 hours a day, seven days a week.


Call us immediately if:

You smell natural gas (exception: a faint odor near an appliance, that goes away after the pilot is lit)
You hear natural gas leaking (hissing sound). 
Your gas service is suddenly interrupted. 

Smell: Nicor Gas adds a distinctive odor to natural gas as a way to alert you to a gas leak. To help you recognize this odor – which many people equate to that of rotten eggs – you can request a scratch and sniff sample. Simply email us with your name, address and number of scratch and sniff slips you are requesting.

A faint gas odor near an appliance may indicate that the pilot light has gone out. If the appliance has a pilot light and the odor persists after relighting, exit immediately, leaving doors and windows open as you exit. Do not open windows if they're not already open. Do not use your telephone or cell phone, operate any appliance, light a match or turn light switches on or off. Call Nicor Gas from a neighboring location.

Even though a distinctive odor is added to natural gas to assist in the detection of leaks, you should not rely solely on your sense of smell to determine if a gas leak exists or if natural gas is present. Some persons may not be able to detect the odorant because they have a diminished sense of smell or olfactory fatigue, or because the odor is being masked by other odors in the area. In addition, certain conditions such as odor fade may cause the odorant to diminish so that it is not detectable.

Odor fade or loss of odorant occurs when the level of odorant in the gas is reduced due to adsorption, absorption and oxidation. Factors that may cause odor fade include the construction and configuration of gas facilities; the presence of rust, moisture, liquids or other substances in the pipe; and gas composition, pressure and/or flow.  Intermittent, little or no gas flow over an extended period of time may also result in the loss of odorant until gas flow increases or becomes more frequent. Many appliance manufacturers include in their installation manuals information on the potential for odorant fade.

Do not purge the contents of a gas line into a confined space. Purging of a gas line should only be done by a licensed, qualified professional and should be done in a well-ventilated area or by venting the contents to the outside atmosphere. Always use gas detection equipment during purging operations or when otherwise working on gas piping systems to ensure that no natural gas is present that may result in a combustible or hazardous atmosphere. DO NOT rely on your sense of smell alone to detect the presence of natural gas.

Consult your local plumbing code, mechanical code, fuel gas code and/or your departments of building, safety or fire for more information. When installing or repairing gas appliances or equipment, the manufacturer's instruction manual should be followed in accordance with the local code authority.

Sound: If you hear a blowing or hissing sound coming from a building that uses natural gas, exit immediately, leaving doors and windows open as you exit. Do not open windows if they're not already open. Do not use your telephone or cell phone, operate any appliance, light a match or turn light switches on or off. Call Nicor Gas from a neighboring location.

Sight: If you see discolored vegetation, blowing dirt or bubbling water in the area of a buried natural gas pipeline, this could indicate a natural gas leak. Call Nicor Gas or your local fire department and keep people away from the suspect area.

Learn more about other safety topics such as: