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Carbon Monoxide (CO) is a colorless, odorless, tasteless gas that is very dangerous to humans. It is a by-product of incomplete combustion (unburned fuel such as gas, oil, wood, etc.). Low concentrations of CO can go undetected and may contribute to ongoing, unidentified illnesses. At high concentrations, it can be deadly. If there is CO in the air you breath, it will enter your blood system the same way oxygen does: through your lungs. The CO displaces the oxygen in your blood, depriving your body of oxygen. When the CO displaces enough oxygen, you suffocate. Newer homes can be especially susceptible to CO because they are often built for energy efficiency allowing less natural ventilation.

WHAT ARE THE SYMPTOMS OF CARBON MONOXIDE POISONING? Long-term exposure to low concentrations can cause mild headaches, fatigue, nausea, dizziness, confusion, and shortness of breath with only moderate exertion. Continued exposure to high concentrations can lead to confusion, severe headaches, severe dizziness, and severe breathing difficulties. With enough exposure, brain damage and death will result. Carbon monoxide poisoning is called "The Great Imitator" because the symptoms are very similar to the flu.

WHO IS AT GREATER RISK? Senior citizens and the elderly, pregnant women and their unborn babies, infants and young children, and people with respiratory or coronary problems. Vulnerable people who are exposed even to low levels of CO for long time periods may have similar health effects to those exposed to high concentrations of CO. Illness in a pet with these symptoms just preceding illness in a family member may suggest CO poisoning.

WHAT CAN PRODUCE CO IN OUR HOMES? Solid fuels, such as wood, always produce carbon monoxide when they are burned, although gas and liquid fuels may or may not produce CO. Anything that burns fuel or generates combustion gases can produce dangerous levels of CO. Common sources are: Automobile exhaust in attached garages - accounts for 60% of all CO alarms. Cars warmed up in the garage trap CO inside the garage which finds its way into the home.Gas stoves - accounts for 20% of CO alarms. It is the result of poor installation, poor maintenance, misuse, or lack of sufficient venting.Poor draft/venting for fuel burning objects - accounts for almost 20% of CO alarms. This may result from ventilation problems from a blocked chimney flue or inadequate venting of furnace, fireplace, or appliance. Other reasons are poor installation and negative air pressure, causing backdrafting, often due to improperly working exhaust fans.Inadequate combustion air to the furnace can result in incomplete combustion. If the furnace has a cracked heat exchanger, it is possible to get CO into the circulating air. It is imperative not to deprive heating equipment and fuel burning appliances of air, especially in air-tight homes where running exhaust fans can result in a shortage of combustion air. Other sources of CO poisoning include leaks in chimney or flue pipe, poorly vented or maintained fireplace, barbecues, boilers, space heaters, and hot water heaters.

HOW CAN I GUARD AGAINST CO POISONING? The first line of defense is to have your home heating systems, fuel burning appliances, flues and chimneys checked and/or cleaned annually. Items to check include blocked openings to flues and chimneys, cracked, rusted, or disconnected flue pipes, dirty furnace filters, rusted or cracked heat exchangers, soot or creosote build-up inside fireplaces and chimney flues, and exhaust or gas odors. If you have an attached garage, it should have gas proofing and automatic closers for doors into the home. To be safe, do not warm your car in an attached garage especially with the door closed. The second line of defense is to install CO detectors. Change the batteries once a year on a day you will remember such as your anniversary or January 1st. Technology has improved, so if you have older CO detectors, replace them with newer ones, doing some research online for reliability-tested models. A CO detector should be placed on each floor of a home, and possibly two per floor in very large homes.

Richard D. Malin & Associates: Technical Library

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