Leaving a gas stove on can be fatal. The danger is divided into two primary categories that pose distinct threats to life. The first involves the release of raw, unburned gas, which carries the risk of explosion and oxygen deprivation. The second, and often more insidious threat, is the production of an invisible, odorless poison when the stove is lit but operating improperly. Understanding these mechanisms is the first step toward safeguarding a home against these domestic hazards.
Dangers from Unlit Burners
Leaving a gas burner on without a flame releases unburned natural gas, which is primarily methane, directly into the surrounding air. Natural gas itself is highly flammable and when mixed with oxygen in a confined space, it can reach an explosive concentration. This is the most immediate danger associated with an unlit leak.
A small ignition source, such as the arc from flipping a light switch, the cycling of a refrigerator motor, or even a static electricity spark, can trigger an explosion. Utility companies add a chemical called mercaptan, which creates a distinct, rotten-egg smell, to alert occupants to this buildup of unburned gas. However, relying on smell alone is unreliable, as factors like a diminished sense of smell or odor fatigue can mask the warning sign.
Raw gas can lead to simple asphyxiation. Natural gas is not chemically toxic, but when its concentration in the air becomes high enough, it displaces the oxygen necessary for breathing. If the oxygen level drops significantly, it can lead to unconsciousness and death due to oxygen deprivation. This risk is heightened in smaller, poorly ventilated spaces where the gas can accumulate rapidly.
The Risk of Carbon Monoxide Poisoning
The other danger comes from a lit gas stove that is not burning cleanly, known as incomplete combustion. When gas burns with sufficient oxygen, it produces mostly carbon dioxide and water vapor. However, when the oxygen supply is limited, the result is the formation of carbon monoxide (CO). This colorless, odorless, and tasteless gas is often called the “silent killer” because it is undetectable by human senses.
Carbon monoxide is deadly because of its interaction with the bloodstream’s hemoglobin. CO has an affinity for hemoglobin that is over 200 times greater than that of oxygen, effectively outcompeting oxygen molecules. When inhaled, CO binds to hemoglobin, forming carboxyhemoglobin, which prevents red blood cells from delivering oxygen to the body’s tissues and organs.
Symptoms of mild to moderate CO poisoning are often vague and can be mistaken for the flu, including headache, dizziness, nausea, and general weakness. As exposure continues, symptoms progress to confusion, loss of muscle coordination, and loss of consciousness. A common indicator of incomplete combustion is a yellow or orange flame on the burner, whereas a clean-burning flame should be blue or blue-violet.
Immediate Safety Measures and Prevention
Safeguarding against gas leaks and carbon monoxide requires preventative measures and a clear emergency plan.
Prevention
Installation of carbon monoxide detectors near sleeping areas and on every level of the home is a necessary step. These detectors provide an essential warning against the odorless CO, while natural gas detectors can offer an early alert to an unburned gas leak.
Proper ventilation is necessary when a gas stove is in use to ensure complete combustion and prevent the buildup of combustion byproducts. Use the range hood fan or open a window to introduce fresh air into the cooking area. All fuel-burning appliances should be inspected by a qualified professional annually to check for proper function and venting.
Emergency Response
If you suspect a gas leak due to the smell of mercaptan or a hissing sound, you must evacuate the area immediately. Do not turn any electrical devices or lights on or off, as the small spark can ignite the gas. Once safely outside, call the local gas company or emergency services. If you experience symptoms of CO poisoning, move to fresh air immediately and seek emergency medical attention.