Methane is non-toxic and creates no hazard when inhaled in limited quantities; however, if large quantities of natural gas or methane is allowed to displace air, lack of oxygen may result in suffocation.
Methane can be flammable when mixed with air between certain concentrations (4.5% to 15%) and where there is an ignition source.
SoCalGas conducts extensive safety programs to prevent the escape of natural gas from its system; and as a health and safety precaution, adds a distinctive odor to natural gas so most people can easily notice its presence.
If you smell a natural gas odor, hear the hissing sound of gas escaping or see other signs of a leak, REMAIN calm. DON'T smoke or light a match, candle or other flame. DON'T turn electrical appliances or lights on or off, operate machinery, or use any device that could create a spark. IMMEDIATELY EVACUATE the area, and from a safe location, call SoCalGas at 1-800-427-2200, or call 911 if the damage results in a natural gas leak that may endanger life or cause bodily harm or property damage.
Further information is available on our Natural Gas Leaks webpage.
Some persons may not be able to smell the odor because they have a diminished sense of smell, olfactory fatigue (normal, temporary inability to distinguish an odor after prolonged exposure to it), a temporary loss of smell due to COVID-19, or because the odor is being masked or hidden by other odors that are present, such as cooking, damp, musty or chemical odors. In addition, certain pipeline and soil conditions can cause odor fade (the loss of odorant so that it is not detectable by smell).