Ideally, natural gas burns in an appliance completely and efficiently, mixing with the oxygen in the air to produce harmless carbon dioxide (CO2) and water vapor. But if conditions aren't right, the natural gas won't combust completely, giving off deadly fumes of carbon monoxide (CO).
When humans breathe in carbon monoxide, it enters the bloodstream and depletes oxygen from the blood cells. Exposure is harmful at high levels over a short period of time, or at lower levels over a longer period - overnight, for example. Carbon monoxide can be especially dangerous during the winter, when our homes are sealed up tight.
Symptoms mimic the flu
The early effects of CO poisoning mimic the flu, so watch for these warning signs:
If the flu-like symptoms are NOT accompanied by fever, if everyone in the family is ill, or if the symptoms disappear when you leave the house, you may have a CO problem - have your gas appliances checked by a service technician right away.
It's important to catch CO problems in the early stages. If exposure continues, the poisoning reaches the central nervous system, resulting in memory loss, slurred speech, loss of consciousness and eventually death.
Carbon monoxide poisonings are often detected by family or friends telephoning a disoriented victim; if you notice any of these symptoms in someone you know, call 911.
Preventing carbon monoxide
Prevention is the only way to deal with carbon monoxide, and the best prevention is regular inspection by a service technician.
An appliance could produce carbon monoxide if:
Natural gas furnaces should be inspected every year; other appliances, such as water heaters, clothes dryers and stoves, should be checked every two years. If you have a natural gas fireplace, it should be serviced regularly as well.
Carbon monoxide concentrations and symptoms