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 are not right, the natural gas will not combust completely, giving off deadly fumes of carbon monoxide (CO).
The dangers of carbon monoxide:
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:
Headache
Nausea or vomiting
Dizziness and disorientation
Muscle weakness or fatigue
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 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 concentrations and symptoms
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:
Boxes, laundry or other materials are blocking the base, restricting oxygen flow.
The vent hood, pipes or flues are blocked or corroded.
The unit is installed or adjusted improperly.
It’s used incorrectly(i.e. heating a room with a gas stove).
The heat exchanger is cracked
Natural gas furnaces should be inspected each 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 service regularly as well.
Carbon monoxide detectors
If you have natural gas appliances, a carbon monoxide detector is a must for keeping your family safe.
These devices work like smoke detectors, sounding an audible alarm if a certain level of carbon monoxide (CO) is detected.
The best CO detectors are electronic alarms that notify you if the level of CO is your home reaches 50 parts per million. A digital model will have a display panel showing the exact levels detected.
You can choose from alarms that are battery-powered, hard-wired or plug into an outlet. Keep these tips in mind:
For battery-powered models, change the batteries a minimum of every six months. An easy way to remember is whenever you change your clocks for Daylight Savings Time.
For hard-wired or plug-in models, remember that these won’t work during a power outage. If a storm knocks out your power for an extended period, make sure to reset the detector when service is restored.
A CO detector should be installed near living and sleeping areas of your home. Placing it in a basement near the furnace could produce false reading and make it difficult to hear the alarm.
Carbon monoxide concentrations and symptoms
35 parts per million (ppm) = No adverse effects within eight hours
200 ppm = Mild headache after two to three hours of exposure
400 ppm = Headache and nausea after one to two hours
800 ppm = Headache, nausea and dizziness after 45 minutes; collapse after two hours
1000 ppm = Loss of consciousness after one hour
1600 ppm = Headache, nausea and dizziness after 20 minutes; unconsciousness after 30 minutes
3200 ppm = Headache, nausea and dizziness after 5-10 minutes; unconsciousness after 30 minutes12,800 = Immediate physiological effects; unconsciousness and danger of death after only one to three minutes
