Natural gas itself does not inherently contain carbon monoxide. The concern regarding carbon monoxide (CO) arises from its combustion. When natural gas is burned, especially in household appliances, the conditions of that burning process determine whether this dangerous gas is produced.
What Natural Gas Is
Natural gas is a naturally occurring gaseous hydrocarbon compound. Its primary component is methane (CH4), typically making up about 85% to 97% of its volume. Other gases present in smaller amounts include ethane, propane, butane, carbon dioxide, nitrogen, and sometimes helium. Natural gas is colorless and odorless, so a chemical odorant, often smelling like rotten eggs, is added for safety to help detect leaks.
How Carbon Monoxide is Produced
Carbon monoxide is produced when fuels, including natural gas, burn incompletely. Complete combustion, with an adequate supply of oxygen, results in the formation of carbon dioxide (CO2) and water (H2O). However, if there is insufficient oxygen during the burning process, carbon atoms in the fuel cannot fully combine with oxygen, leading to the formation of carbon monoxide (CO) instead of carbon dioxide. This can occur in natural gas appliances such as furnaces, water heaters, stoves, or clothes dryers if they are not properly maintained or vented. Blocked flues or chimneys, or insufficient air supply to the combustion chamber, can also lead to incomplete combustion and CO buildup.
Risks of Carbon Monoxide Exposure
Carbon monoxide is a gas that has no odor, taste, or color, making it particularly dangerous as it cannot be detected by human senses. When inhaled, CO enters the bloodstream and binds to hemoglobin, the molecule in red blood cells responsible for carrying oxygen throughout the body. This binding affinity is approximately 200 to 250 times greater than that of oxygen, effectively displacing oxygen and depriving tissues and organs of the oxygen they need to function. This leads to cellular hypoxia, which can cause severe tissue damage.
Symptoms of carbon monoxide poisoning often resemble those of the flu, including headache, dizziness, weakness, nausea, and confusion. Continued exposure can result in blurred vision, sleepiness, loss of muscle control, and ultimately loss of consciousness, brain damage, or even death. Individuals who are asleep or have pre-existing health conditions, such as heart or lung disease, are at increased risk for more severe outcomes.
Ensuring Home Safety
Protecting against carbon monoxide exposure in homes using natural gas involves several proactive measures. Installing carbon monoxide detectors is a primary safety step, as these devices can alert occupants to the presence of CO before dangerous levels are reached. It is recommended to place detectors on every level of the home, including the basement, and outside each sleeping area. Detectors should be kept at least 10 to 15 feet away from fuel-burning appliances to prevent false alarms due to trace emissions upon startup.
Regular professional maintenance and inspection of all natural gas appliances, including furnaces, water heaters, and stoves, are also important. Qualified technicians can ensure appliances are operating efficiently and that ventilation systems are clear and unobstructed. Proper ventilation is essential, and it is important to never use gas ovens or ranges as a source of heat for the home, as this can lead to CO buildup.