Carbon Monoxide (CO) is a colorless, odorless gas that is produced as a by-product of the burning of fossil or wood fuels. Statistics indicate that approximately 200 people accidentally die from CO poisoning and many more are treated by hospital emergency rooms. Because the symptoms of CO are common, i.e. fatigue, dizziness, headaches and nausea they can easily be mistaken. If any type of combustible is burned in the house for any purpose, a CO detector is highly recommended.

CO in the Home

Carbon Monoxide is left over when fire burns its fuel. If a house is primarily heated by oil, gas, propane, wood, or coal; a detector is recommended near the furnace, especially if there is living space near the furnace. When the systems are operating properly, CO entering the home should not be a problem. Unfortunately, over time and use, units may allow CO to enter the home without the homeowner being aware of it.

Problems encountered routinely that allow CO into the home are chimney pipes or flues from furnaces, hot water heaters or gas clothes dryers that are improperly attached, corroded or even missing. These connections should be checked once a month to insure they are not leaking. A very good indication that they are leaking is an accumulation of soot under or around the piping.

Another common problem, especially in older furnaces are cracked fireboxes or heat exchangers. Because soot and dirt can effectively hide these cracks, it is important to have a licensed heating specialist inspect the inside of the furnace checking for cracking and proper burner operation. Many companies offer very good prices on yearly service plans so call around for the best price. Some regional utility companies may offer the same service and are worth exploring. Whichever route is decided, it is important to keep the system well maintained.

Every year there are stories of people dyeing from CO poisoning because of un vented heaters, most notably Kerosene heaters. These portable heaters can generate a lot of heat and a lot of CO. If these heaters are to be used, it is highly recommend that a CO monitor be used in conjunction with them. Proper ventilation is a must and no matter how cold outside, a window or door should be kept open to allow fresh to circulate through the room with the heater.

Fireplaces and chimneys are another possible source of CO into the house. A routine inspection of the chimney should be conducted to insure that the chimney is not clogged or the chimney opening is not obstructed. A chimney cap will help in preventing animals from entering the chimney and causing problems. A quality chimney cleaner should be consulted to clean the chimney when a build up is noted in the chimney. This will need to be done more frequently if a sappy wood is burnt like pine. Also periodically check the flue openings venting furnaces as these stacks can also, over time, build up soot and block proper venting of the exhaust.

One of the most common causes of death from CO is caused by portable gas heaters. Care should always be taken when operating these heaters in an enclosed area. Because these heaters normally have a high BTU (measurement of heat the unit outputs), they are very susceptible to both consuming large amounts of oxygen. In a small, poorly ventilated room, these heaters can actually consume most of the oxygen in a room. This coupled with the fact that they are un vented and as such are replacing the burnt oxygen with CO can lead to a potentially deadly combination. In any room where a portable, gas-burning heater is used, a CO detector should be placed.

Homes with attached garages in which the car is parked in the garage can also cause CO problems in the home. In colder climates, many people will start their cars in closed garages to warm up the car. Depending on the size of the garage, it may only take a couple of minutes for levels of CO to reach hazardous levels. It is recommended that the garage be at least partially open if the car is going to be run in it. If this option is not desirable, a CO monitor should be placed in the garage in clear view warning of high levels of CO. One final warning regarding garages. Because the garage is an enclosed, indoor space, barbecue grills should not be operated in the garage. Many of these grills, especially those burning charcoal can emit large quantities of CO. If a grill is to be used in the garage, the garage door MUST be left open. A CO detector is also highly desirable in the garage to monitor levels.

What is CO and how to measure it?

Carbon monoxide directly affects the hemoglobin in blood that carries oxygen for the body. When it combines with the hemoglobin it forms Carboxyhemoglobin (COHb). Depending on age and health, levels as low as 10-15 percent COHb can be harmful. One of the most common side effects of low level COHb exposure is headaches and dizziness. It is very important not to discount a headache in a home where CO poisoning is possible. If it is thought that CO poisoning is a possible source of headaches or dizziness, immediately open windows in the house to allow fresh air to ventilate throughout the house. If symptoms persist, purchase a CO detector to test the levels of CO in the house. Because there are quite a few different CO detectors on the market, there are certain features that should be looked for when purchasing one.

According to Consumer Reports magazine, the most accurate CO models are those that are the plug-in variety. Any model that is chosen should have the Underwriter Labs (UL) stamp of approval. A good feature to look for is a constant read detector that shows the CO levels with up to the minute data. Any detector that is bought should have a Reset/ Hush switch so that the buzzer indicating high CO concentrations can be turned off. The best detectors will allow owners to reset them and start testing the air for CO again. If CO is high; they will again sound an alarm. If the alarm does sound repeatedly and symptoms of CO poisoning are being felt by anyone in the house, either a qualified heating specialist or the fire department should be called to investigate further. Leave the house until they arrive to prevent further CO poisoning.

If the alarm goes off but no one feels the symptoms of CO, open windows in the house and shut off all possible sources of CO. Call a qualified repairperson to investigate further. CO is a potentially deadly gas so any indications that there might be CO infiltration should be investigated further immediately.

As with all components of a house, routine inspection and maintenance should be conducted to keep the systems in good working order. For heating systems, a service contract should be started to regularly inspect the system. A chimney cleaner should be contracted for regular cleaning of flues and chimneys. A visual inspection of all piping that vents exhaust should be regularly conducted.