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worker detecting a leak
worker detecting a leak

Emergency Information

Smell Gas?

LOOK for discolored vegetation, blowing dirt or continued bubbling water in the area of a buried gas line.
LISTEN for a hissing sound.
SMELL for the distinctive “rotten egg” odor of natural gas.
Natural gas is a colorless, odorless fuel. As a safety precaution, we add a chemical odorant called mercaptan that gives natural gas an odor often associated with rotten eggs. This distinctive scent allows you to smell a potential leak if it occurs. Always leave if you suspect a leak.
Natural gas is non-toxic, lighter than air and displaces oxygen. In severe cases, if not used properly, it may lead to asphyxiation, and has a risk of ignition near a spark.


Note: Always leave if you suspect a leak. Be aware that some persons may not be able to detect the odorant because they have a diminished sense of smell, known as olfactory fatigue, or because the odor is being masked by other odors in the area. Certain conditions may cause the odorant to diminish so that it is not detectable.

Never try to find the leak yourself.
LEAVE the area immediately, warning others in the area as you leave. Keep everyone away from the area until emergency assistance arrives.
AVOID touching anything that may cause a spark. This includes lighters, matches, cigarettes, flashlights, light switches and telephones in the area of the suspected leak. Wait until you are a safe distance away before using your cell phone.
CALL Nicor Gas at 888.Nicor4U (888.642.6748) and emergency responders at 911 once you are in a safe place, away from the area of the suspected leak. Stay away until emergency personnel indicate it is safe to return.

CO: Signs & Leak Prevention

carbon monoxide detector

Signs of carbon monoxide buildup

  • Stuffy or stale air
  • Very high humidity
  • Fallen soot from your chimney or draft hood
  • A hot draft coming from your draft hood

    If carbon monoxide has been backing up into your living space for some time, you may experience carbon monoxide poisoning. While carbon monoxide poisoning is extremely rare, be aware of the following symptoms:

  • Headaches
  • Dizziness and weakness
  • Nausea and vomiting
  • Stinging eyes
  • Sleepiness
  • Heart flutters
installing proper ventilation in home roof

Proper ventilation

Carbon monoxide is an invisible, odorless gas that can cause illness and even death when not properly vented by your furnace or appliances. Carbon monoxide comes from the incomplete combustion of common fuels such as heating oil, gasoline, coal, wood, charcoal, kerosene, propane and natural gas. When properly operated and maintained, natural gas heating equipment and appliances are safe and efficient.


But if your appliances or heating equipment are not properly operated and vented, carbon monoxide could back up into your living space.

Improper venting can be caused by the following:

  • Chimneys or vents blocked by leaves, bird nests, debris or heating residue 
  • Malfunctioning or wrongly installed equipment 
  • Heating equipment improperly enclosed by paneling or other structures 
  • Improperly vented equipment

Carbon monoxide detectors

There are many carbon monoxide detectors on the market. Regardless of brand, the detector you purchase should meet current UL standards and must be installed and operated according to the manufacturer’s instructions. Homeowners and landlords throughout Illinois are required by law to install carbon monoxide (CO) detectors.

Public Act 094-0741 requires every dwelling be equipped with at least one approved carbon monoxide alarm, in operating condition, within 15 feet of every sleeping room. This alarm may be battery operated, plug-in with battery back-up or wired into the home's AC power with a secondary battery back-up. Approved alarms bear the label of a nationally recognized testing laboratory and comply with the most recent standards of the Underwriters Laboratories or the Canadian Standard Association.

Carbon monoxide safety tips

  • Install a carbon monoxide detector.
  • Have an HVAC technician check your heating equipment annually.
  • Keep the area surrounding your gas appliances clear from clutter or trash.