A carbon monoxide detector is a device present in many structures, particularly homes, that is used to detect carbon monoxide (CO) levels in the air and to warn the inhabitants of the building when carbon monoxide levels are dangerously high in order to prevent carbon monoxide poisoning. Carbon monoxide is a colorless and odorless compound produced by incomplete combustion. It is often referred to as the "silent killer" because it is virtually undetectable without using detection technology. When inhaled, carbon monoxide enters the bloodstream and binds to hemoglobin, a protein that is normally used for oxygen transportation. Carbon monoxide prevents oxygen from binding to the hemoglobin, resulting in an inadequate supply of oxygen reaching the organs in the body. The use of a carbon monoxide detector is one simple preventative measure that greatly reduces the risk of carbon monoxide poisoning.
Carbon monoxide detectors are designed to measure CO levels over time and sound an alarm before dangerous levels of CO accumulate in an environment, giving people adequate warning to safely ventilate the area or evacuate. Some system-connected detectors also alert a monitoring service that can dispatch emergency services if necessary.
While carbon monoxide detectors do not serve as smoke detectors and vice versa, dual smoke/carbon monoxide detectors are also sold. Smoke detectors detect the smoke generated by flaming or smoldering fires, whereas carbon monoxide detectors detect and warn people about dangerous CO buildup caused, for example, by a malfunctioning fuel-burning device. In the home, some common sources of CO include open flames, space heaters, water heaters, blocked chimneys or running a car inside a garage.
Carbon monoxide detectors can be acquired easily and at minimal expense. Some governments, particularly at regional levels, even require carbon monoxide detectors to be installed in houses during construction. The alarm units require almost no maintenance; some have batteries that need to be replaced after a period of five years or more, while others can be powered by the building's electrical system. Unlike smoke detectors, carbon monoxide alarms do not necessarily need to be installed near the ceiling because, unlike smoke, carbon monoxide has approximately the same density as air and tends to be evenly spread throughout the air. Some smoke detectors actually include a built-in carbon monoxide alarm, removing the need to have two separate devices.
There are many different methods through which a carbon monoxide alarm can detect the presence of carbon monoxide in the air. Some contain a synthetic version of hemoglobin; an alarm sounds when carbon monoxide binds to it. Others contain electrochemical cells that respond to changes in the concentration of various gases in the air. Semiconductors are also sometimes used as carbon monoxide alarms, but electrochemical cells tend to perform appreciably better.
It is important for a carbon monoxide detector to be able to communicate the presence of high levels of carbon monoxide to the inhabitants of a structure. The traditional method of doing so involves a loud alarm, but this can sometimes be ineffective for heavy sleepers or for people with poor hearing. In such cases, a carbon monoxide alarm may be wirelessly connected to strobe lights or to a vibrating pad inside of one's pillow. These overlapping measures ensure that one is able to respond quickly to a threat from carbon monoxide.
Carbon monoxide is an odorless, colorless gas which is formed through the partial combustion of carbonaceous material. Although this gas is very structurally simple, it is also very deadly, and it poses a serious health risk since people can be severely injured through slow exposure over time as well as through brief exposure to high levels of this gas. Carbon monoxide is also very useful; it is an important gas in many industrial processes, and it is even deliberately generated by many chemical manufacturers.
The chemical formula of carbon monoxide is CO, meaning that it has one oxygen atom and one carbon atom. Any sort of combustion will produce carbon monoxide gas in varying levels, which normally dissipates into the atmosphere; inefficient combustion can generate dangerously high levels of this gas. In a confined space, carbon monoxide can become very dangerous. One of the most common sources of dangerous carbon monoxide is household appliances like heaters and stoves, along with internal combustion engines such as those found in cars. Proper ventilation of any sort of equipment which burns carbonaceous material is extremely important.
When animals and people are exposed to carbon monoxide, the gas binds to the red blood cells in the body, interfering with their ability to carry oxygen. The gas can stay in the body for an extended period of time, making it possible for people to slowly get sick from carbon monoxide poisoning. It can take several hours for the body to express the harmful carboxyhaemoglobin which is formed as a result of carbon monoxide exposure.
Carbon monoxide poisoning is characterized by fatigue, difficulty concentrating, lethargy, and chest pain. Tissues in the extremities of the patient will also start to die as a result of the restricted flow of oxygen. If left untreated, carbon monoxide poisoning can cause a coma, and ultimately death. The condition is diagnosed by testing CO levels in the blood, and it is treated with inhalation of oxygen, often in a hyperbaric chamber; the high pressure hastens the expression of carboxyhaemoglobin from the body.
In the home, it is a very good idea to purchase, use, and regularly test carbon monoxide detectors. In addition to warning you of a dangerous carbon monoxide leak caused by faulty devices, these detectors can also indicate a smoldering fire. You should also regularly check your appliances for efficiency, and make sure that your home is well vented so that this harmful gas will not accumulate in your home. Several companies also make CO detectors for vehicles.
What is carbon monoxide (CO) and how is it produced?
Carbon monoxide (CO) is a deadly, colorless, odorless, poisonous gas. It is produced by the incomplete burning of various fuels, including coal, wood, charcoal, oil, kerosene, propane, and natural gas. Products and equipment powered by internal combustion engines such as portable generators, cars, lawn mowers, and power washers also produce CO.
How many people are unintentionally poisoned by CO?
On average, about 170 people in the United States die every year from CO produced by non-automotive consumer products. These products include malfunctioning fuel-burning appliances such as furnaces, ranges, water heaters and room heaters; engine-powered equipment such as portable generators; fireplaces; and charcoal that is burned in homes and other enclosed areas. In 2005 alone, CPSC staff is aware of at least 94 generator-related CO poisoning deaths. Forty-seven of these deaths were known to have occurred during power outages due to severe weather, including Hurricane Katrina. Still others die from CO produced by non-consumer products, such as cars left running in attached garages. The Centers for Disease Control and Prevention estimates that several thousand people go to hospital emergency rooms every year to be treated for CO poisoning.
What are the symptoms of CO poisoning?
Because CO is odorless, colorless, and otherwise undetectable to the human senses, people may not know that they are being exposed. The initial symptoms of low to moderate CO poisoning are similar to the flu (but without the fever). They include:
Headache
Fatigue
Shortness of breath
Nausea
Dizziness
High level CO poisoning results in progressively more severe symptoms, including:
Mental confusion
Vomiting
Loss of muscular coordination
Loss of consciousness
Ultimately death
Symptom severity is related to both the CO level and the duration of exposure. For slowly developing residential CO problems, occupants and/or physicians can mistake mild to moderate CO poisoning symptoms for the flu, which sometimes results in tragic deaths. For rapidly developing, high level CO exposures (e.g., associated with use of generators in residential spaces), victims can rapidly become mentally confused, and can lose muscle control without having first experienced milder symptoms; they will likely die if not rescued.
How can I prevent CO poisoning?
Make sure appliances are installed and operated according to the manufacturer's instructions and local building codes. Most appliances should be installed by qualified professionals. Have the heating system professionally inspected and serviced annually to ensure proper operation. The inspector should also check chimneys and flues for blockages, corrosion, partial and complete disconnections, and loose connections.
Never service fuel-burning appliances without proper knowledge, skill and tools. Always refer to the owners manual when performing minor adjustments or servicing fuel-burning equipment.
Never operate a portable generator or any other gasoline engine-powered tool either in or near an enclosed space such as a garage, house, or other building. Even with open doors and windows, these spaces can trap CO and allow it to quickly build to lethal levels.
Install a CO alarm that meets the requirements of the current UL 2034 safety standard. A CO alarm can provide some added protection, but it is no substitute for proper use and upkeep of appliances that can produce CO. Install a CO alarm in the hallway near every separate sleeping area of the home. Make sure the alarm cannot be covered up by furniture or draperies.
Never use portable fuel-burning camping equipment inside a home, garage, vehicle or tent unless it is specifically designed for use in an enclosed space and provides instructions for safe use in an enclosed area.
Never burn charcoal inside a home, garage, vehicle, or tent.
Never leave a car running in an attached garage, even with the garage door open.
Never use gas appliances such as ranges, ovens, or clothes dryers to heat your home.
Never operate unvented fuel-burning appliances in any room where people are sleeping.
Do not cover the bottom of natural gas or propane ovens with aluminum foil. Doing so blocks the combustion air flow through the appliance and can produce CO.
During home renovations, ensure that appliance vents and chimneys are not blocked by tarps or debris. Make sure appliances are in proper working order when renovations are complete.
What CO level is dangerous to my health?
The health effects of CO depend on the CO concentration and length of exposure, as well as each individual's health condition. CO concentration is measured in parts per million (ppm). Most people will not experience any symptoms from prolonged exposure to CO levels of approximately 1 to 70 ppm but some heart patients might experience an increase in chest pain. As CO levels increase and remain above 70 ppm, symptoms become more noticeable and can include headache, fatigue and nausea. At sustained CO concentrations above 150 to 200 ppm, disorientation, unconsciousness, and death are possible.
What should I do if I am experiencing symptoms of CO poisoning and do not have a CO alarm, or my CO alarm is not going off?
If you think you are experiencing any of the symptoms of CO poisoning, get outside to fresh air immediately. Leave the home and call your fire department to report your symptoms from a neighbor's home. You could lose consciousness and die if you stay in the home. It is also important to contact a doctor immediately for a proper diagnosis. Tell your doctor that you suspect CO poisoning is causing your problems. Prompt medical attention is important if you are experiencing any symptoms of CO poisoning. If the doctor confirms CO poisoning, make sure a qualified service person checks the appliances for proper operation before reusing them.
Are CO alarms reliable?
CO alarms always have been and still are designed to alarm before potentially life-threatening levels of CO are reached. The safety standards for CO alarms have been continually improved and currently marketed CO alarms are not as susceptible to nuisance alarms as earlier models.
How should a consumer test a CO alarm to make sure it is working?
Consumers should follow the manufacturer's instructions. Using a test button tests whether the circuitry is operating correctly, not the accuracy of the sensor. Alarms have a recommended replacement age, which can be obtained from the product literature or from the manufacturer.
How should I install a CO Alarm?
CO alarms should be installed according to the manufacturer's instructions. CPSC recommends that one CO alarm be installed in the hallway outside the bedrooms in each separate sleeping area of the home. CO alarms may be installed into a plug-in receptacle or high on the wall. Hard wired or plug-in CO alarms should have battery backup. Avoid locations that are near heating vents or that can be covered by furniture or draperies. CPSC does not recommend installing CO alarms in kitchens or above fuel-burning appliances.
What should you do when the CO alarm sounds?
Never ignore an alarming CO alarm! It is warning you of a potentially deadly hazard.
If the alarm signal sounds do not try to find the source of the CO:
Immediately move outside to fresh air.
Call your emergency services, fire department, or 911.
After calling 911, do a head count to check that all persons are accounted for. DO NOT reenter the premises until the emergency services responders have given you permission. You could lose consciousness and die if you go in the home.
If the source of the CO is determined to be a malfunctioning appliance, DO NOT operate that appliance until it has been properly serviced by trained personnel.
If authorities allow you to return to your home, and your alarm reactivates within a 24 hour period, repeat steps 1, 2 and 3 and call a qualified appliance technician to investigate for sources of CO from all fuel burning equipment and appliances, and inspect for proper operation of this equipment. If problems are identified during this inspection, have the equipment serviced immediately. Note any combustion equipment not inspected by the technician and consult the manufacturers' instructions, or contact the manufacturers directly, for more information about CO safety and this equipment. Make sure that motor vehicles are not, and have not been, operating in an attached garage or adjacent to the residence.
What is the role of the U.S. Consumer Product Safety Commission (CPSC) in preventing CO poisoning?
CPSC staff worked closely with Underwriters Laboratories (UL) to help develop the safety standard (UL 2034) for CO alarms. CPSC helps promote carbon monoxide safety by raising awareness of CO hazards and the need for correct use and regular maintenance of fuel-burning appliances. CPSC staff also works with stakeholders to develop voluntary and mandatory standards for fuel-burning appliances and conducts independent research into CO alarm performance under likely home-use conditions.
Do some cities require that CO alarms be installed?
Many states and local jurisdictions now require CO alarms be installed in residences. Check with your local building code official to find out about the requirements in your location.
Should CO alarms be used in motor homes and other recreational vehicles?
CO alarms are available for boats and recreational vehicles and should be used. The Recreation Vehicle Industry Association requires CO alarms in motor homes and in towable recreational vehicles that have a generator or are prepped for a generator.
The following reviews have been selected:
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allenJo
You can easily get carbon monoxide poisoning if you sit in a parked car in your garage. It will take awhile admittedly but it can still happen. The carbon monoxide fumes will continue to build up with no outlet until finally you begin to suffocate.
What makes this kind of poisoning so deadly as the article points out is that it gradually builds up. You may not get knocked out suddenly.
Instead you slowly feel tired without really knowing why; you would probably chalk it up to regular fatigue. The next thing you know you're knocked out and you could potentially die.
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everetra
@allenJo - It's not just automobile exhausts that can put you in that state. Household appliances can do that too.
I heard of a lady who had a gas fireplace. She left it on overnight and there were problems with the gas logs. Eventually she fell asleep without realizing what was going on.
She would have died, had it not been for the carbon monoxide alarm which went off. After she awoke she got the call from her alarm company and they told her that the carbon monoxide sensor detected the gas; she turned off the fireplace and waited outside until the firefighters came.
Sure enough they found high quantities of the gas in the house that were slowly building up and suffocating her. That's why it's so important to have these alarms installed in the house. It's the silent, gradual nature of carbon monoxide poisoning that makes it so lethal.
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Charred
Even without an alarm I think practicing carbon monoxide safety procedures will go a long way towards ensuring that you never come down with poisoning.
If you have a gas stove or fireplace running, leave the windows open for proper ventilation. Have your gas appliances checked from time to time.
If you ever do feel symptoms like nausea and fatigue and notice that they only come when you're in the house, that's another clue that something is going on there. Have someone check your house for carbon monoxide as soon as possible.
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whiteplane
It's really important whenever you move into a new place, particularly a rental property, to check if they have a carbon monoxide detector installed. Most places will only provide a smoke alarm but you are putting yourself and your friends and family at risk if you don't also monitor for carbon monoxide.
Another thing to consider is that in a rental property you don't know how well the gas lines. stove and furnace have been maintained. You might move into a place with old and broken down equipment that elevates your risk of carbon monoxide poisoning. Don't put yourself in that position. Go and get a ten dollar detector and know that you are protected.
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drtroubles
Does anyone know what carbon monoxide symptoms appear when you are experiencing poisoning?
My family and I recently purchased a new home and it seems like we've been more tired since we moved in. I am not sure if this is just from the stress due to the move or if there is something worse happening. I know my kids don't have any real reason to be so sluggish as they didn't really have to help with anything during the move. They did put away their own things but I doubt that would make them so sleepy all the time.
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Sara007
@drtroubles - Carbon monoxide detection is important especially in new homes. You would be surprised at the problems you can find after you move even if you have had a home inspection. I would say put in a carbon monoxide detector in and see what it says.
As far as symptoms of carbon monoxide poisoning go generally your family would be experiencing lightheadedness, confusion and headaches. There is also a chance of vertigo, and flu-like effects. I would guess if your family is just feeling tired it is from the move, it can be very stressful even if you don't pick up a box. Get the detector just in case though.
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sunnySkys
@whiteplane - This article and your post especially inspired me to buy a... carbon monoxide detector for my apartment. I have a gas stove, so I feel like I especially need a carbon monoxide detector.
I always knew carbon monoxide was dangerous, but I never really gave any thought to it in relation to myself and my apartment. I suppose I've always assumed the places I lived were well maintained. But I guess there's really no way for me to know how the gas lines are.
Anyway, the detector I ordered should be here in a few days, and I think I'll feel much safer after it does.
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ceilingcat
@sunnySkys - It's always a good idea to have a carbon monoxide detector. I hope you did some research before you made your purchase though. From what I understand, not all carbon monoxide detectors are created equal...
Anyway, it's interesting to know exactly why carbon monoxide kills you. I had no idea that it would bind to red blood cells and interfere with them. I always though it just suffocated you by filling up your lungs or something.
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