Carbon monoxide education with real CO accident examples

Learn from other people’s deadly misfortune.

What everyone needs to know about carbon monoxide!

Carbon monoxide (CO) is a very poisonous gas that can kill quickly and without warning. You cannot see, hear, smell or taste it.

Your best protection from carbon monoxide poisoning is a carbon monoxide alarm and education about carbon monoxide poisoning and its health effects.

What are the most common sources of carbon monoxide?

Please see the house below and click on appliances.  All fossil fuel powered heaters, water heaters, furnaces and other heaters using wood, coal, oil or other carbon based fuels, gas stoves, gas dryers, both gas and wood fireplaces, cooking equipment such as ranges, ovens and BBQs, as well as engines such as power tools, snow blowers, gas or gasoline powered grass cutting equipment, trucks, autos and generators.

Carbon Monoxide (CO) is an odorless, colorless and tasteless -- yet deadly -- gas. It is important to understand what causes it and how to avoid it. There are precautions that will help avoid exposure to carbon monoxide. Click on one of the CO sources in the house pictured below to learn safety tips on how to stop carbon monoxide from invading your home. Click on a specific area or appliance on the house...   If you suspect that CO is contaminating your indoor environment, it is important to act quickly by ventilating the area. If you or a member of your family has flu-like symptoms immediately evacuate the residence and call the gas company, oil company, or fire department from a neighbor's house.   A UL listed carbon monoxide detector is the best protection from this invisible killer. Make sure that the detector or alarm you are using has been fully approved for your intended use. For example, do not use home-use CO alarms in boats or recreational vehicles. Never unplug or remove the battery to silence a CO detector! There have been many cases of people doing this, then they go back to sleep and never wake up! At the very least, ventilate the area and change the detector's battery. Always assume the worst. Back to house A chimney that is blocked or clogged due to a bird's nest, leaves, or soot causes combustion byproducts, including CO, to vent into home. Cracked masonry could also cause a blockage. Periodic inspection and cleaning by a chimney sweep helps prevent any difficulties. A screen cap for the top of the chimney to discourage nest building is also a good idea. Back to house   Wood burning and gas powered fireplaces are a common source of carbon monoxide. Leaving the window open a few inches provides for circulation of fresh air while preventing negative pressure buildup/back drafting which can draw CO and other toxins into the home. Wood burning Fireplaces: Treated woods, painted wood, and scrap lumber should not be burned in a fireplace. Burn only seasoned firewood. Also, before you start a fire in your fireplace, make sure that the damper is open. Always leave the flue open even if the fire is almost out. Those last smoldering embers produce a high concentration of deadly CO. Gas log sets: Gas logs or burners produce a lot of CO since the less-efficient, yellow flames are desired for a cozy atmosphere. If you own a vent less fireplace be particularly careful as these appliances vent all combustion byproducts into the room. As the fireplace is run, oxygen is taken from the room to fuel the combustion process. As less oxygen is available, the combustion becomes less efficient and more CO is produced. Some gas log sets use a sensor that shuts down the appliance if oxygen drops to a certain level. The danger is that the appliance can be producing CO even if oxygen isn't depleted from the immediate environment. It is a good idea to look for an appliance with a CO safety shutoff device. Back to house A furnace produces CO because of a mechanical failure or as a result of a cracked heat exchanger, flue or burner problems. Incorrect installation, damage caused by basement flooding, and pilot lights can produce CO. Also a clogged or dirty burner can affect the air/fuel mixture resulting in inefficient combustion. Yellow flames and soot accumulation are indications that the furnace needs maintenance. Frequent inspection and regular maintenance of the burner, flue, and chimney should greatly reduce any CO difficulties with this appliance. Back to house     Vent less space heaters are so dangerous that some states including California, Colorado, Massachusetts, Minnesota, Montana, New York, Utah and Washington prohibit their use. Some of these heaters use a sensor that shuts down the appliance if oxygen drops to a certain level. The danger is that the appliance can be producing CO even if oxygen isn't depleted from the immediate environment. Never use a heater inside a house or enclosed structure if the operating instructions tell you not to. Portable heaters and all other unvented appliances vent all the combustion products directly into the interior of the home. It is a good idea to look for appliances with CO safety shutoff devices. Also, leave the window cracked a few inches to allow for circulation of fresh air if you are using a portable heater. Back to house   Gas stoves and range tops are common sources of CO in a house since they are often unvented. Regular cleaning of the range top, oven cavity and burners will alleviate some of the problem. If the burners are dirty and clogged, the fuel air mixture becomes improperly adjusted causing inefficient combustion. Older appliances may have rust or damage to the burner system which may cause CO. Other conditions that could result in CO being produced are improper installation or a faulty appliance. Keep in mind that the exhaust fan that is commonly over the range top is unvented and therefore does not help dissipate CO. The fan provides filtration of grease vapor and soot generated during cooking. The best way to avoid these difficulties is to have regular maintenance done to include cleaning and adjustment of the air/fuel mixture. Also, never warm the house using your natural gas or propane oven. Back to house   A water heater is a potential source of carbon monoxide. The appliance may be faulty as purchased or installed improperly. Basement flooding may have caused damage to make the heater function inefficiently. A clogged burner, blocked vent or even the pilot light can produce CO. Danger signs that CO is being produced include a yellow burner flame and soot buildup. Regular maintenance to ensure air/fuel mixture is adjusted correctly and cleaning of the burner components is recommended to ensure protection from CO poisoning. Back to house   A gas clothes dryer that is purchased faulty or installed incorrectly can be a CO hazard. Damage caused by flooding and exhaust pipes clogged with lint could also cause CO to buildup. The burner can become dirty or clogged and affect the air/fuel mixture resulting in inefficient, CO-producing combustion. Frequent inspection and regular maintenance of the burner are good preventive measures. Also, clean the lint filter after every load of laundry. Back to house   Grills, barbecues and hibachis should never be used indoors, or even inside the garage or on a porch or patio. The smoldering embers of charcoal produce great amounts of CO. Always take care to grill a fair distance away from the windows of your house. Back to house   Probably the greatest CO danger in a residence is a running car in an attached garage, especially if the garage door is closed.   Take these precautions: Never warm up your car in the garage. Even if the garage door is open, a pocket of CO could form due to temperature variances. Wind can help or hinder dispersion of CO.   Leave the overhead door open for at least a few minutes after you have pulled your car into the garage. The same precautions should be followed when using any combustion appliance including lawnmowers, snow blowers, generators, lawn tools, snow mobiles, motorcycles, etc.   Also, garages should have outside air vents.   Multiple car garages, as are common in apartment houses and condos, are particularly dangerous. A commercial CO detector that activates ventilation controls is recommended for use in these structures. Back to house   Insulation does reduce heat loss and keeps those energy bills down but remember you are also cutting down your fresh air supply in your home making combustion less efficient and increasing your CO risk. Creating an energy efficient home could create a negative pressure and cause a back drafting effect that would draw fumes into your home instead of exhausting them to the exterior. All fuel-burning appliances need to be in good working condition and exhausted to the exterior. Remember that it is always a good idea to make sure there is adequate fresh air for efficient combustion to take place. Crack your window or door. Saving a life is more important than saving a few dollars on your fuel bill. Back to house

CO can be produced by combustion that occurs from fossil fuel burning appliances.  When appliances and vents work properly, and there is enough fresh air in your home to allow complete combustion, the trace amounts of CO produced are typically not dangerous. And normally, CO is safely vented outside your home.

CO levels can rise to dangerous levels if an appliance is installed improperly, if a portable generator is less than 25 feet from the house or other structure, if a forced air furnace is over 20 years old or if a newer one has been exposed to corrosive materials. When we analyze accidents the weather sometimes plays a key role.  If you have a pool heater outside and you have not had a serious problem it does not mean an accident can’t happen.  When the wind is low velocity and blowing into the house, CO levels can become lethal. It has happened to a doctor and his family.  In this incident, the unit had been installed for about one year before the deadly accident occurred.  In this case the workers installed a natural gas pool heater and the home was supplied with a propane gas supply. Because of a combination of factors (wind velocity, wind direction, improper installation, length of time in use, building construction, and location of the installed pool heater) a three year child was killed and their parents and others were very seriously injured.

It can happen when people move a charcoal BBQ into the garage to get it out of the rain.  It has happened.  People have used charcoal for heating and they paid with their lives.

Other dangerous CO events can occur when something goes wrong with a good installation such as birds building a nest or leaves plugging a vent. Appliances can malfunction, a furnace heat exchanger can crack causing CO to come into a house instead of going out the vent, gas logs can be adjusted to create pretty yellow flames, which can increase CO output dramatically.

Never leave a vehicle running.  Vehicles rank as the second most common fatal CO accident. Fire is the number one cause of fatal CO accidents. CO is produced by burning most household materials such as drapes, paper, clothing, rugs, furniture and plastics as well as any material that contains carbon.  It is a major killer.  Exhaust can seep into the home from vehicles left running in an attached garage.  All these things can cause very serious and even fatal CO levels in the home.

You need to be aware that CO kills people sitting in a car for prolonged periods of time with the engine running.  Just talking on the phone people have died from CO in their car.

Every year police officers, lovers and others succumb to CO poisoning in vehicles.  Statistics from the Journal of American Medical Association (a refereed journal, unlike the Internet, provides careful review before publishing) states that there are over 5600 deaths per year from CO in the USA.  About 3100 of which are accidental, of those 1550 are from fires, 1150 are from engine exhaust and 500 from home appliances.