Where does carbon dioxide come from in your house


Carbon Monoxide In Your Home

May 2, 2013 | Blog

Carbon Monoxide – What’s all the fuss about?

California now requires homeowners to install carbon monoxide detectors in their homes. Many heating and air conditioning professionals have been recommending them for years, long before the law was put into place. Why? Well, it is a gas that is colorless, odorless, tasteless, and deadly to humans. The minimal cost of detectors and some other precautions are well worth it! If those proper precautions are taken, the risk of ingesting the deadly gas can be all but eliminated.

So how does it get into my house?

Carbon monoxide is the byproduct of partial combustion. When there is not quite enough oxygen around when an appliance is burning fuel, it will produce carbon monoxide. This is often true because it is extremely difficult to get an appliance running absolutely perfectly and then keep it that way through the life of the system.

During normal operation, the deadly gas is simply blown to the outdoors through the appliance’s exhaust vent. Once it is outside, the gas is harmless because it dissipates and very small amounts of it are found in the air all the time. Forest fires, volcanoes, and other naturally occurring events produce the gas on a regular basis.

The gas ends up in your house when an appliance is not venting properly. This could happen if your water heater does not have enough draft to pull the exhaust out of the house. It also could happen if your furnace has a crack in its heat exchanger. The heat exchanger is just like your car’s exhaust pipe but it’s inside your furnace.

Have you ever noticed how hot your car’s exhaust pipe gets? In the furnace, indoor air is blown across the heat exchanger in order to heat up the air and then the air is blown back into the house. As the furnace runs, it continually burns gas to keep that heat exchanger hot. The exhaust fumes are pulled through that heat exchanger and then blown outside through the exhaust vent.

When the heat exchanger cracks, exhaust gases, including carbon monoxide, get mixed in with the indoor air and it’s blown into the house. This is much like running a car and blowing the car’s exhaust into the house. In this case, however, the exhaust gas is odorless, colorless and tasteless so you could get poisoned by it before even noticing that it was there.

I pay for maintenance on my furnace, doesn’t that cover me?

As a major part of routine maintenance, Lee’s does perform an inspection of the heat exchanger. If the technician notices a crack, the gas will be shut off to the unit immediately and the customer will be notified as soon as possible.

Unfortunately, most heat exchangers are not completely visible during routine maintenance. The technicians are trained to know where cracks are likely to occur and to use mirrors and other methods to view those areas; however, some areas simply cannot be seen without completely uninstalling and disassembling the furnace. That would be comparable to removing and reinstalling the engine of your car every time you wanted to get your oil changed and engine serviced.

Having your furnace maintained will do a great deal to help extend the life of your heat exchanger and to prevent cracks from occurring, but cracks can still happen and still can go unseen.

What else should I do to protect my home and my family?

The best thing to do is to go to your local hardware store and pick up a few carbon monoxide detectors for your home. Some are fairly inexpensive. Some require wiring and others are simply battery operated. They look like standard smoke detectors and some even come as a smoke detector and carbon monoxide detector combination.

With whatever device you choose, you must follow the manufacturer’s instructions, and change batteries if necessary if it is going to be of any use at all. This, in conjunction with routine furnace maintenance, will give you peace of mind when it comes to the threat of carbon monoxide.

What should I do if my carbon monoxide detector goes off?

    • Turn off all appliances immediately. If you do not know how to turn off a particular appliance, do not spend time trying to figure it out. Proceed to step two.
    • Leave the building and open doors and windows on the way out if at all possible.
    • Do a head-count to make sure that everyone is out of the building.
    • Check to see if anyone is experiencing any of the symptoms of carbon monoxide poisoning which include nausea, vomiting, shortness of breath, fatigue, drowsiness, dizziness, confusion, and headaches.
    • If anyone is experiencing symptoms, call 911.
    • Call a professional to have your appliances inspected and do not go back into the building until it is determined to be safe.

How long does it take for carbon monoxide to get out of my house or my body?

Carbon monoxide is slightly lighter than air. It will dissipate if appliances are off and windows and doors are open. How long it takes to get out of your building just depends on how much air is flowing through it.

Getting the gas out of your body is a different story. Carbon monoxide has a half-life in a human body of about 5 hours. This means that if you are breathing fresh, carbon monoxide-free air, it will take five hours to get half the carbon monoxide out of your system. Then it will take another five hours to cut that level in half, and so on. It is best to consult a medical professional if you feel the symptoms of carbon monoxide poisoning.

People do not need to be living in constant fear of carbon monoxide but what they do need to do is just make sure that they are taking the simple precautions necessary to make sure that they are protected from it.

Carbon Monoxide (CO) is gas you cannot see or smell which is produced by the incomplete processing of solid, liquid, and gaseous fuels, as well as appliances fuelled with oil, liquefied petroleum (LP gas), natural gas, coal, kerosene, or wood. Burning charcoal or running a non-electric machine (car or lawn mower) produces CO gas.

Normally, the small amounts of CO released by heating equipment in the home are vented outside and do not build up inside, but when the air circulating your rooms and heating systems is not properly vented, or when there is a leakage that causes the rate of CO buildup to be greater than that of the venting, the high levels of carbon monoxide displace oxygen in the blood, resulting in CO poisoning – a blockage of normal oxygen delivery to the tissues.

CO is very dangerous, and is often called the “silent killer” because it is hard to detect it until it is too late. Though many victims of CO poisoning recover with treatment, severe cases can cause permanent brain damage.

Signs of a carbon monoxide leak in your house or home

Despite the fact that you can neither smell nor see or taste the gas, there are few signs you can look for to detect a carbon monoxide leakage or buildup in your home, including:

  1. Dripping or heavy condensation on the windows where the appliance is installed – this can be a great indicator if you have taken measures to reduce moisture production, though it could also imply that the humidifier is set very high
  2. Sooty or brownish-yellow stains around the leaking appliance
  3. Stale, stuffy, or smelly air, like the smell of something burning or overheating
  4. Soot, smoke, fumes, or back-draft in the house from a chimney, fireplace, or other fuel burning equipment
  5. The lack of an upward draft in chimney flue
  6. Fallen soot in fireplaces
  7. Solid fuel fires burning slower than usual
  8. The smell of unusual gases in your house. While carbon monoxide is odourless, sometimes it is accompanied by exhaust gases you can in fact smell
  9. A pilot light that is frequently blowing out
  10. A yellow burner flame instead of the usual clear blue flame, though this is not applicable to natural gas fireplaces that intentionally generate the yellow flame for aesthetic purposes

If you’re late detecting the CO leakage, you may need to take fast action if you notice early symptoms of carbon monoxide poisoning, like tightness across the forehead, followed by pounding of the heart and headache. When progressive poisoning occurs, the victim’s face becomes extremely red accompanied by dizziness, weariness, and mental changes.

However, very concentrated CO may cause the victim to pass out without feeling any of these symptoms.

Carbon Monoxide Safety

The first line of defence against carbon monoxide poisoning is making sure that your home’s heating equipment is being inspected on an annual basis: including gas appliances, chimneys and vents. CO alarms are a good second line of defence that should be installed on every level of the home and tested regularly. Also, you should never use grills, BBQs, or charcoal fuel burners in unventilated spaces, and keep your rooms well ventilated at all times.

For more information, contact a.p.i. Alarm Inc.!

Every year in the UK around 200 people are admitted to hospital with suspected carbon monoxide poisoning, leading to around 40 deaths. So it’s important that we know the facts for our own, and our children’s, health and safety. Here’s everything you need to know…

What is carbon monoxide poisoning?
Carbon Monoxide (CO) is a gas – it can be very dangerous to your health and can be fatal. It is sometimes referred to as the silent killer because it has no smell, taste or colour, which makes it difficult to detect. CO is produced when fuels such as gas, oil, coal or wood do not burn fully.

When you breath in CO, it enters your bloodstream and mixes with haemoglobin (the part of red blood cells that carry oxygen around the body), to form carboxyhaemoglobin. This stops your blood from being able to carry oxygen which causes the body’s cells and tissue to die.

Around 10-15% of people who suffer from severe or life-threatening CO poisoning develop long-term complications, such as damage to the brain or the heart.

How do you know if you’re suffering from carbon monoxide poisoning?
Initial symptoms of CO poisoning can be similar to flu, but without a fever and sometimes, can be confused with food poisoning. The most common symptoms include: dizziness, headaches, nausea and vomiting, tiredness and confusion, stomach pain, shortness of breath and difficulty breathing.

What causes a carbon monoxide leak in the home?
The most common causes are incorrectly installed, poorly maintained or poorly ventilated household appliances like fires (if the chimney or flue is blocked), cookers, heaters and central heating boilers.

Who is most at risk?
‘High risk’ groups include the elderly, children, pregnant women and people with respiratory problems or chronic heart disease. It is now a legal requirement for private landlords to fit a CO alarm in rooms used as living accommodation which also contain an appliance that burns, or is capable of burning solid fuel. Although there is no requirement to fit one near a gas boiler, it is still advisable as best practice.

What to do if you think someone is suffering from carbon monoxide poisoning?
The official NHS advice says you should:

  • Stop using all appliances and evacuate the property immediately – stay calm and avoid raising your heart rate.
  • Call the gas emergency number on 0800 111 999 to report the incident – or Health and Safety Executive (HSE) Gas Safety Advice Line on 0800 300 363.
  • Do not go back into the property – wait for advice from the emergency services.
  • Get immediate medical help – you may not realise if you’re badly affected and going outside into fresh air won’t treat any exposure by itselfHow can you protect yourself from carbon monoxide poisoning in the home?
  • Install a carbon monoxide alarm near appliances that are capable of producing CO.

How to prevent a leak
Firstly, and most importantly, you must install an alarm – if your children are in rented accommodation, check that they have one too. You also need to look out for other tell-tale signs:

  • Black, sooty marks on the front covers of gas fires, or sooty marks on the walls near boilers, stoves or fires.
  • Smoke building up in rooms because of a faulty flue or blocked chimney.
  • Gas appliances producing yellow flames instead of blue ones.

Ensure all appliances are installed and regularly serviced by registered engineers if you have a chimney.

For more information, visit npower’s advice pages.

All images: Getty

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How to Detect Carbon Monoxide in Your Home

Carbon Monoxide and Your Health

When carbon monoxide gas contaminates the air, you breathe in more carbon monoxide than oxygen. Once it enters the body, carbon monoxide gets into the blood, where it takes the place of oxygen; this happens most notably in vital organs like the brain and heart, which then become oxygen-deprived.

The first symptoms of carbon monoxide poisoning include:

  • Chest tightness or shortness of breath
  • Tiredness
  • Nausea
  • Confusion
  • Headaches
  • Dizziness

How carbon monoxide affects your health depends on the amount of carbon monoxide exposure and on how long the exposure lasts. Carbon monoxide poisoning may cause some of the immediate short-term effects noted above, but it can quickly turn serious, with nausea, vomiting, and loss of muscle coordination coming next. Inhaling high quantities of carbon monoxide can quickly lead to unconsciousness and suffocation.

Preventing Carbon Monoxide Poisoning

A carbon monoxide detector is a must for any home and just as important as a smoke detector. CO detectors should be placed near all bedrooms; they’re the only way you will know if carbon monoxide is affecting the air quality in your home, and can help prevent serious illness and even death.

Follow all the manufacturer’s directions, including how often the unit needs replacing, and always make sure there’s a UL (Underwriters Laboratories) certification tag on the model you buy. Unfortunately, not all carbon monoxide detectors are 100 percent effective — some brands did well during independent testing, and others didn’t. Investigate models before you buy to choose one that rated highest in tests.

If you experience any carbon monoxide poisoning symptoms, even if the detector alarm hasn’t sounded, get everyone out of your house into fresh air immediately.

According to the U.S. Environmental Protection Agency, using a carbon monoxide detector is only a part of effective prevention. Also be sure all fuel-burning appliances get regular maintenance and are working properly. To reduce the risk of carbon monoxide in your home, follow these tips:

  • Always open the flue when using a fireplace.
  • Never leave your car turned on in the garage; for instance, if you warm it up before driving in the winter, do it outside.
  • Be cautious using wood-burning stoves: Make sure they are certified by the U.S. Environmental Protection Agency, and that the doors close tightly.
  • Use appropriate fuel in kerosene heaters.
  • Keep all gas appliances in your home working properly and inspect them often.
  • Have your furnace and entire heating system inspected and cleaned each year by a professional.
  • Never use gasoline-powered machines or charcoal grills indoors.
  • Quickly repair any leaks in your central heating system.

It’s important to take these safety precautions to make sure that you keep carbon monoxide out of your home. Carbon monoxide monitors, used in conjunction with preventive safety tips, can help you keep you and your family safe from carbon monoxide poisoning.

Early symptoms of exposure to CO, after breathing it for a short time, include:

  • Dull headache
  • Shortness of breath during mild exertion
  • Weakness or fatigue
  • Dizziness

Continued exposure to CO may result in:

  • Nausea or vomiting
  • Visual disturbances, such as blurred vision
  • Difficulty concentrating

Prolonged exposure and lack of medical treatment may lead to serious and long-term effects and may even be life-threatening.

Is it carbon monoxide poisoning or the flu?

Thornley notes that many of these symptoms — headache, dizziness, nausea and fatigue — can be confused with the common flu. How can you tell if what you or your children are experiencing is CO poisoning rather than the flu?

  • “Flu is passed from one family member to another, and usually does not affect everyone in the family at the same time,” says Thornley. “If everyone in your home or in your car, including pets, begins to feel these signs of sickness within a short amount of time, be alert to the possibility of CO poisoning.”
  • “Symptoms of the flu do not improve after leaving the affected space, and are usually relieved with proper medication,” Thornley continues. “If the symptoms improve when you go outside, or are not relieved with medication, you may be experiencing CO poisoning.”

What to do when you suspect carbon monoxide poisoning

If CO is detected with an alarm device, or if you suspect from your symptoms that you or your family members have been exposed to CO, leave the area of exposure immediately and go to the emergency department. Call the Poison Control Center at 1-800-222-1222 for further instruction. The gas company, oil company or local health authority can provide help in identifying and removing sources of CO contamination.

Preventing carbon monoxide poisoning

Fuel-burning products and engines produce carbon monoxide, as do some chemical products, such as paint strippers. When engines are working properly and CO-producing products are used with appropriate ventilation, they aren’t normally a cause for concern. But when an engine’s exhaust is blocked in some way, or if CO-producing products are used in a closed space, the carbon monoxide can build to dangerous levels.

Follow these recommendations to help prevent carbon monoxide poisoning:

  • Install a battery-operated or battery back-up CO alarm in the home and replace the batteries every year.
  • Place generators as far from homes as possible (minimum of 25 feet), but also at a safe distance from any nearby dwellings.
  • Never leave a car running in the garage or another enclosed space. CO can accumulate even when the garage door is open.
  • Never use a generator, grill, camp stove, or other gasoline or charcoal-burning device inside a home, basement, garage, or outside near an open window.
  • Never heat homes with a gas oven or by burning charcoal.
  • Ensure that fuel-burning space heaters are properly vented.
  • Maintain your heating system, water heater, and any gas, oil, or coal burning appliances with annual service appointments with a qualified technician.
  • Do not use portable flameless chemical heaters indoors. These types of heaters burn gas and can cause CO to build up inside your home.
  • Leave the building and dial 911 if a CO alarm sounds, if CO poisoning is suspected, or if any person begins to feel dizzy, light-headed or nauseous.
  • After a major snowstorm, your car’s exhaust pipe may be blocked by snow, causing the gas to back up into the car. To protect yourself and your passengers from carbon monoxide poisoning, avoid being in the car with the engine running when there is a risk of your tail pipe being blocked.

For suspected cases of CO poisoning and other exposures, call your regional poison center at 1-800-222-1222.

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Carbon Monoxide (CO) Poisoning in Your Home

Download a printable version of the brochure Carbon Monoxide: Preventing carbon monoxide poisoning in your home (PDF)

Carbon monoxide (CO) is an odorless, colorless gas formed by the incomplete combustion of fuels. When people are exposed to CO gas, the CO molecules will displace the oxygen in their bodies and lead to poisoning.

The Problem with CO

Since CO has no odor, color or taste, it cannot be detected by our senses. This means that dangerous concentrations of the gas can build up indoors and humans have no way to detect the problem until they become ill. Furthermore, when people become sick the symptoms are similar to the flu, which can cause victims to ignore the early signs of CO poisoning.

The CDC estimates that approximately 400 people die from unintentional CO exposure in the United States every year. Data specific to Minnesota show that an average of 14 people die due to unintentional CO poisoning each year. The same data shows that another 307 people visit emergency department each year for treatment of symptoms linked to unintentional CO exposure. For more data information Carbon Monoxide Data Portal.
The good news is that carbon monoxide poisoning can be prevented with simple actions such installing a CO alarm and maintaining fuel burning appliances.

Carbon Monoxide Sources in the Home

In simple terms, CO is produced whenever a material burns. Homes with fuel-burning appliances or attached garages are more likely to have CO problems Common sources of CO in our homes include fuel-burning appliances and devices such as:

  • Clothes dryers
  • Water heaters
  • Furnaces or boilers
  • Fireplaces, both gas and wood burning
  • Gas stoves and ovens
  • Motor vehicles
  • Grills, generators, power tools, lawn equipment
  • Wood stoves
  • Tobacco smoke

Typical Indoor CO Concentrations

Ideally, the level of CO indoors should be the same as CO concentrations outside. In the Minneapolis/St. Paul metro area, outdoor CO levels typically range from 0.03-2.5 parts per million (ppm) averaged over an 8-hour period. These levels are well below the federal standard of 9 ppm for CO in outdoor air. In general, concentrations are lower in rural areas and higher in urban areas. Finding CO concentrations higher indoors than outdoors indicates a source of CO either inside or very close to your home.

CO and Recreation

There are a number of ways people can be exposed to high levels of carbon monoxide while participating in activities such as camping, fishing, hunting and boating.

  • Items such as camp stoves, charcoal grills, fuel-burning lanterns and generators should never be used inside a tent, RV or cabin
  • Do not place portable generators near open doors and windows
  • Ice fishing houses that use heating equipment should have a working CO alarm installed and users should crack a window for additional ventilation
  • Heating equipment in cabins and ice houses should be regularly inspected and be in good condition
  • Boaters should be aware of exhaust area at the back of the boat and should tow passengers at least 20 feet from this area
  • Be aware of exhaust from neighboring boats when parked near them
  • Consider installing a CO alarm in the cabin of boats

1. Properly vent and maintain fuel-burning appliances

It is important to know what appliances in your home are fuel-burning and make sure that they are maintained properly. All of these appliances should be vented to the outside. You should have your fuel-burning appliances (ex. furnace) checked by a qualified heating contractor every year to look for potential problems. It is also a good idea to know the signs of a potential CO problem:

  • Streaks of soot around fuel-burning appliances, or fallen soot in a fireplace
  • Absence of an upward draft in your chimney
  • Excess moisture and condensation on windows, walls and cold surfaces
  • Rusting on flue pipes or appliance jacks
  • Orange or yellow flame in combustion appliances (the flame should be blue)
  • Damaged or discolored bricks at the top of the chimney

Never use appliances intended for outdoor use inside. Examples include barbecue grills, camp stoves, portable generators or gas-powered lawn equipment. Do not use an oven to heat your home. Not only is it a fire risk, it is also a carbon monoxide hazard. Do not run or idle your vehicle in an attached garage. Instead, back your vehicle out right away. Check that your vehicle’s exhaust pipe is not blocked, for example, by snow during the winter.

2. Know the symptoms of CO poisoning

Identifying CO poisoning can be difficult because the symptoms are similar to the flu. CO is often called the “silent killer” because people will ignore early signs and eventually lose consciousness and be unable to escape to safety.

For most people, the first signs of exposure include mild headache and breathlessness with moderate exercise. Continued exposure can lead to more severe headaches, dizziness, fatigue and nausea. Eventually symptoms may progress to confusion, irritability, impaired judgment and coordination, and loss of consciousness.

You can tell the difference between CO poisoning and the flu with these clues:

  • You feel better when you are away from home
  • Everyone is the home is sick at the same time (the flu virus usually spreads from person to person)
  • The family members most effected spend the most time in the house
  • Indoor pets appear ill
  • You don’t have a fever or body aches, and you don’t have swollen lymph nodes that are common with the flu and some other infections
  • Symptoms appear or seem to get worse when using fuel-burning equipment

3. Install and maintain CO alarms in your home

Minnesota state law (MN Statute 299F.50) requires that every home have at least one operational CO alarm within 10 feet of every room legally used for sleeping. All CO alarms should conform to the latest Underwriters Laboratory (UL) Standards. Please follow the manufacturer’s instructions for placement of your CO alarm, and take note of the suggested replacement date.

Frequently Asked Questions

Are some people at greater risk of CO poisoning?

Yes, some people are at a greater risk for CO poisoning. Those individuals include people with:

  • Respiratory conditions, such as asthma or emphysema
  • Cardiovascular disease
  • Anemia or sickle cell anemia

Also, the elderly and young children are at a greater risk for CO poisoning than adults. Individuals engaging in strenuous activity have also been found to be at greater risk. Remember, ANYONE can become sick and die from CO poisoning when exposed to very high levels.

Can CO be a problem in the summer?

Yes. Although CO poisoning cases are higher during the winter months, there are situations where people can be exposed to high levels of CO during the summer. Vehicles including boats produce carbon monoxide. Devices such as camp stoves, barbecue grills and non-electric heaters are commonly used during recreational activities and also are sources of CO.
The CDC has noted that CO poisoning cases have resulted from the use of power generators during power outages. Portable generators are capable of producing more carbon monoxide than modern cars and can kill people in a short amount of time. It is recommended that users place generators at least 25 feet away from and downwind of a house. Be sure that there are no vents or openings near the generator that would allow exhaust to enter into your home.

How long do CO alarms last?

The typical lifespan of a CO alarm is between 5 and 7 years, but it varies by manufacturer. Consult the product packaging or manufacturer for a recommended replacement date.

What do I do when my CO alarm sounds?

Don’t ignore a CO alarm if it is sounding. If people in the home are exhibiting symptoms of CO poisoning, immediately leave the building and call your local fire department. In cases where residents are feeling fine, call your local gas utility company or a qualified technician to help identify the cause of the problem.

Carbon Monoxide Poisoning FAQs

Frequently Asked Questions About Carbon Monoxide, Carbon Monoxide Symptoms & Carbon Monoxide Poisoning


  • Carbon Monoxide is a colorless, odorless and tasteless poison gas that can be fatal when inhaled.

  • It is sometimes called the “silent killer.”

  • CO inhibits the blood’s capacity to carry oxygen.

  • CO can be produced when burning fuels such as gasoline, propane, natural gas, oil or wood.

  • CO is the product of incomplete combustion. If you have fire, you have CO.


  • Any fuel-burning appliance that is malfunctioning or improperly installed.

  • Furnaces, gas range/stove, gas clothes dryer, water heater, portable fuel-burning space heaters, fireplaces, generators and wood burning stoves.

  • Vehicles, generators and other combustion engines running in an attached garage.

  • Blocked chimney or flue.

  • Cracked or loose furnace exchanger.

  • Back drafting and changes in air pressure.

  • Operating a grill in an enclosed space.


Initial symptoms are similar to the flu without a fever and can include dizziness, severe headaches, nausea, sleepiness, fatigue/weakness and disorientation/confusion.


  • Common Mild Exposure – Slight headache, nausea, vomiting, fatigue, flu-like symptoms.

  • Common Medium Exposure – Throbbing headache, drowsiness, confusion, fast heart rate.

  • Common Extreme Exposure – Convulsions, unconsciousness, brain damage, heart and lung failure followed by death.

  • If you experience even mild CO poisoning symptoms, immediately consult a physician!


  • Properly equip your home with carbon monoxide alarms on every level and in sleeping areas. The only safe way to detect CO in your home is with a CO alarm.

  • Every year have the heating system, vents, chimney and flue inspected by a qualified technician.

  • Regularly examine vents and chimneys for improper connections, visible rust and stains.

  • Install and operate appliances according to the manufacturer’s instructions.

  • Only purchase appliances that have been approved by a nationally recognized testing laboratory.

  • Never use a gas range/stove to heat the home.

  • Never leave your car idling in a closed garage or use fuel-powered appliances or tools in enclosed, attached areas such as garages or porches. Carbon monoxide can seep into your home through vents and doors.


  • Every home with at least one fuel-burning appliance/heater, attached garage or fireplace should have a carbon monoxide alarm.

  • If the home has only one carbon monoxide alarm, it should be installed in the main bedroom or in the hallway outside of the sleeping area.

  • An alarm should be installed on every level of the home and in sleeping areas.

  • Place the alarm at least 15 feet away from fuel-burning appliances.

  • Make sure nothing is covering or obstructing the unit.

  • Do not place the unit in dead air spaces or next to a window or door.

  • Test the carbon monoxide alarm once a week by pressing the test/reset button.

  • Every month, unplug the unit and vacuum with a soft-brush attachment or wipe with a clean, dry cloth to remove accumulated dust.


A digital display allows you to see if CO is present and respond before it becomes a dangerous situation.

Peak Level Memory stores the highest recorded reading prior to being reset. This feature enables you to know if there was a reading while you were away from home, and also can help emergency responders determine the best treatment.


If anyone is experiencing symptoms, you need to get everyone into fresh air and call 911 from a neighbor’s home. If no one is experiencing symptoms, you should call the fire department or a qualified technician from a neighbor’s home to have the problem inspected. If you are unable to leave the home to call for help, open the doors and windows, and turn off all possible sources while you are waiting for assistance to arrive. Under no circumstance should an alarm be ignored!

Sources of Carbon Monoxide Poisoning in the Home

Carbon monoxide (CO) is a dangerous gas that can be found inside your home. The scary thing about carbon dioxide is that it is odorless, tasteless and colorless, which means it cannot be detected by the human senses.

CO is created by the incomplete combustion of fuels and when exposed, the CO molecules will displace the oxygen in your body and lead to poisoning. It’s not just a hazard to your health; carbon monoxide is deadly.

Why Carbon Monoxide is Dangerous

Since we cannot see, taste or smell carbon monoxide, it is impossible to know you are inhaling it until you begin to become ill. The symptoms of CO poisoning are similar to those of the flu, so you may just think you’re sick with a virus rather than suffering from CO poisoning.

The Center for Disease Control (CDC) estimates that around 400 people in the US fall victim to CO poisoning and die every year. It is vital that CO detectors be installed inside your home alongside home security systems and smoke detectors in order to protect yourself and your family.

(Source: CDC)

Common Sources of Carbon Monoxide Poisoning

Carbon monoxide is created whenever a material is burned. So, homes with fuel burning appliances such as stoves, ovens, and heaters are more likely to be at risk for CO issues and exposure.

Some of the most common sources of CO in our homes include:

  • Gas space heaters
  • Furnaces and chimneys
  • Clothes dryers
  • Water heaters
  • Gas stoves
  • Generators
  • Ovens
  • Motor vehicles, especially if parked in an attached garage
  • Tobacco smoke
  • Grills
  • Power tools and lawn equipment

With so many sources of carbon monoxide in or near the home, it’s crucial that you know what steps to take to prevent carbon monoxide poisoning.

What are Safe Carbon Monoxide Levels?

The general rule is the CO levels inside should not exceed CO levels outside. Depending on where you live, the outside CO levels will differ. Typically, outdoor CO levels are lower in rural areas and are higher in more urban areas due to higher population density and heavier traffic.

The federal standard for CO in outdoor air is 9 parts per million. If CO levels inside your home are higher than the outside air, this could indicate a problem inside your home and you should address this problem immediately.

Preventing Carbon Monoxide Poisoning

Since CO poisoning is preventable, it is important to know and understand how to protect your family against its deadly fumes.

Proper Ventilation

Find out which appliances in your home are fuel-burning and to make sure that they are vented and maintained properly.

Additionally, you should have all these appliances checked by a certified professional on a yearly basis to ensure that they are functioning correctly. It is also wise to know the warning signs to check for yourself. If you experience any of the following, contact a professional right away:

  • Fallen soot in your fireplace
  • Lack of an upward draft in your chimney
  • Excess moisture on windows and walls
  • Discolored or damaged bricks at the top of your chimney

These can all indicate that your fuel-burning appliance has issues and that you need to call a professional contractor right away.

A frequent culprit of major CO emissions is your car. It can be tempting to start your vehicle inside your garage, especially in the winter time, to warm it up before heading out.

If your garage is attached to your home, do not leave the car running while inside your garage. Back your vehicle out of the garage if it is running to avoid CO gas from entering your home.

It is also important to make sure that your tailpipe is not blocked or obstructed in any way. An obstructed tailpipe will result in CO entering the interior of the car and this could be life-threatening.

Install a Carbon Monoxide Detector

The number one thing that you can do to prevent dangerous carbon monoxide poisoning is to install and maintain properly functioning CO detectors in your home. Carbon monoxide detectors are an essential part of any home security system, along with fire protection devices like smoke detectors.

Check your state laws to see what their specific regulations are regarding where and how many CO detectors need to be placed in your home to keep you safe.

  • Mass.gov
  • Connecticut Public Act No. 13-272
  • Ri.gov

You should regularly test your carbon monoxide detectors to make sure they work correctly and plan to replace the batteries at least twice a year. Set a reminder on your calendar if you think you won’t remember.

CO detectors typically last for between five and seven years, after which you will want to replace them for optimal performance and that your equipment is up to date with the highest safety standards.

Carbon Monoxide Poisoning Symptoms

Although it is difficult to tell if you are being affected by high levels of CO, it is important to know and understand the symptoms to prevent serious complications and even death.

CO poisoning has been dubbed the “silent killer” because of how difficult it is to detect. Typically, the first indication of CO poisoning is a headache and mild shortness of breath, especially when doing something that requires physical exertion. As exposure continues, your symptoms will increase in intensity; severe headaches, fatigue, nausea and dizziness will ensue.

Overtime, your symptoms related to CO exposure will progress to a stage of confusion, impaired judgment and finally a loss of consciousness.

How to Discern CO Poisoning from the Flu

  • Everyone who lives in the home is sick at the same time
  • Your symptoms subside when you are away from home
  • Your pets are beginning to feel ill as well
  • You are not feeling the common body aches and fever that typically come with the flu

If any of the above apply to you, there is a good chance that CO poisoning is the culprit and not the flu.

If you recognize any of these risk factors, it is important that you leave your home as soon as possible and call a professional to get the problem resolved before re-entering your home.

What to do if your Carbon Monoxide Detector goes off

Never ignore a CO detector when it goes off.

  • Turn off all appliances.
  • Open as many doors and windows as you can
  • Leave your home immediately and call 911 or your local fire department.

If no one is reporting feeling ill, but the alarm is going off, it is a good idea to call your local gas company or a certified technician to come to check on things.

There are many hazards in our home that we often overlook, carbon monoxide poisoning is one of these. There is a simple solution to protect you and your family from becoming victims of this poison — a Carbon Monoxide (CO) Alarm. In addition to installing this very simple device (it is very similar to a smoke detector), the CPSC recommends “consumers to have a professional inspection of all fuel- burning appliances — including furnaces, stoves, fireplaces, clothes dryers, water heaters, and space heaters — to detect deadly carbon monoxide leaks.”

— Medical Editor, MedicineNet.com

Household Hazard – Carbon Monoxide “CO” Poisoning Warning

After a recent rash of carbon monoxide poisonings – including incidents in Maryland, Pennsylvania and New Jersey — the U.S. Consumer Product Safety Commission (CPSC) is repeating its recommendation that every home should have a carbon monoxide (CO) alarm. CPSC also urges consumers to have a professional inspection of all fuel- burning appliances — including furnaces, stoves, fireplaces, clothes dryers, water heaters, and space heaters — to detect deadly carbon monoxide leaks.

These appliances burn fuels, such as gas, both natural and liquefied petroleum; kerosene; oil; coal; or wood. Under certain conditions, fuel-burning appliances can produce deadly CO. However, with proper installation and maintenance, they are safe to use.

CO is a colorless, odorless gas produced by burning any fuel. The initial symptoms of CO poisoning are similar to the flu, and include headache, fatigue, shortness of breath, nausea and dizziness. Exposure to high levels of CO can cause death.

“CO poisoning associated with using fuel-burning products kills more than 200 people each year,” said CPSC Chairman Ann Brown.

CPSC recommends that the yearly professional inspection include checking chimneys, flues and vents for leakage and blockage by creosote and debris. Leakage through cracks or holes could cause black stains on the outside of the chimney or flue. These stains can mean that pollutants are leaking into the house. In addition, have all vents to furnaces, water heaters, boilers and other fuel-burning appliances checked to make sure they are not loose or disconnected.

Make sure your appliances are inspected for adequate ventilation. A supply of fresh air is important to help carry pollutants up the chimney, stovepipe or flue, and is necessary for the complete combustion of any fuel. Never block ventilation air openings.

CPSC recommends that every home should have at least one CO alarm that meets the requirements of the most recent Underwriters Laboratories (UL) 2034 standard or International Approval Services 6-96 standard.
For more information about carbon monoxide poisoning, please see the MedicineNet.com:

  • Dictionary entry to Carbon Monoxide Poisoning
  • Health Fact, Gasoline-Powered Generators – Not For Indoor Use Warning!
  • Doctors’ View, Automobile Carbon Monoxide Poisoning Danger in Winter Storms

(Source, CPSC January 18, 2001, Press Release #01-069)

How does carbon monoxide (CO) affect me?

In a typical year, nearly 400 Americans die from carbon monoxide poisoning, usually in their own home or car. Many of those deaths happen during the winter months, when people are heating their homes and reducing the amount of outside ventilation.

Even if CO levels are not high enough to be fatal, they can produce serious illness.

Where does carbon monoxide come from?

Carbon monoxide is produced by devices that burn fuels.

Your furnace, water heater, stove, space heaters, fireplace, woodstove, charcoal grill, and dryer can be sources of CO, especially if they are not in good working condition or have been installed without proper ventilation.

Vehicle exhaust fumes from attached garages also can become CO hazards.

Using kerosene heaters or charcoal grills indoors, or running a car in a garage can cause CO levels to rise high enough to result in death or serious illness.

How do I know if carbon monoxide is present?

Unlike natural gas or LP gas, which have a characteristic odor added to them to alert you, carbon monoxide has no fumes and no color.

We breathe in CO like normal air with no irritation to our nose or throats. Then, our blood cells attach with CO molecules instead of oxygen molecules, starving our organs from the oxygen they need.

For these reasons, CO is called the silent killer.

The best way to alert you and your family to unsafe levels of CO is to install a carbon monoxide detector. It works like a smoke alarm, sampling the air in your home and creating a loud alarm when levels of the gas are detected.

It’s important to evacuate your home immediately when your CO alarm sounds. While there’s no risk of an explosion, as there would be with natural gas, the effects of CO in your blood are accumulative, and the longer you’re exposed to it the longer it takes to rid your body of its effects.

What are some symptoms of carbon monoxide poisoning?

Most people with a mild exposure to carbon monoxide experience headaches, fatigue, and nausea. Unfortunately, the symptoms are easily overlooked because they are often flu-like.

Medium exposure can cause you to experience a throbbing headache, drowsiness, disorientation, and an accelerated heart rate.

Extreme exposure usually leads to unconsciousness, convulsions, cardiorespiratory failure, coma, and eventually death.

Too often, death from CO poisoning results with the victim simply falling asleep and never regaining consciousness.

How do I protect myself and my family from carbon monoxide poisoning?

Your garage

  • Always back your car out of the garage to let it warm up. Never leave it running in the confined space of a garage, particularly if the garage is attached to the home.
  • Never run lawnmowers, snowblowers, or other gas-powered engines in confined areas like garages or sheds.
  • Never use ovens or grills to heat your home or garage.

Your car

  • Never dismiss a fender bender as something you’ll get checked later. Even minor collisions can cause breaks in your car’s exhaust system, allowing CO to enter into your passenger area.
  • If you get stuck in deep snow by the side of the road and decide to stay in your car and keep warm with your engine running, be sure to clear snow away from your exhaust pipe. A blocked exhaust pipe can cause CO to back up into your passenger area.

Your home

  • Never use a cooking device—an oven, grill, or camp stove—to heat your home.
  • Install a carbon monoxide alarm on each level of your home as your first line of defense. CO detectors are most effective when used in conjunction with preventive maintenance.
  • Replace old or faulty central heating and air conditioning units with new and improved models.
  • Make sure any heating and air conditioning system is installed by trained professionals with proper ventilation.
  • Maintain your heating and air conditioning system regularly, usually just before each big change of season.

How do you get dangerous levels of carbon monoxide out of a person’s blood?

The treatment for carbon monoxide poisoning is high-dose oxygen. Using higher atmospheric pressure around the body can speed up the effectiveness of the high-dose oxygen treatment.

University of Iowa Hospitals & Clinics has the area’s only multi-person hyperbaric chamber, a capsule that uses a combination of high oxygen levels and high atmospheric pressure to safely and quickly remove dangerous levels of CO from the body.

The Hyperbaric Medicine Facility, staffed 24-hours a day, is large enough for several members of a family to be treated at the same time.

Carbon monoxide poisoning

On this page

  • Symptoms of carbon monoxide poisoning
  • Preventing carbon monoxide poisoning
  • Carbon monoxide alarms
  • About carbon monoxide
  • More information

Symptoms of carbon monoxide poisoning

Carbon monoxide can cause health problems before you even notice that it’s present. Breathing it in reduces your body’s ability to carry oxygen in your blood. Exposure to the gas can cause carbon monoxide poisoning (CO poisoning) and can be dangerous to your health.

At low levels, effects include flu-like symptoms, such as:

  • tiredness
  • headaches
  • shortness of breath
  • impaired motor functions, such as:
    • muscle weakness
    • partial or total loss of function of a body part (limb or limbs)

At high levels, or if you are exposed to low levels for long periods of time, you can experience:

  • dizziness
  • chest pain
  • poor vision
  • difficulty thinking

At very high levels, it can cause:

  • convulsions
  • coma
  • death

Preventing carbon monoxide poisoning

Keep your home and cottage air clean and free of carbon monoxide by:

  • preventing indoor smoking
  • keeping the door between your house and the garage closed
  • not idling vehicles in the garage, even when the garage door is open

Never use:

  • gas-powered machines in the garage, such as:
    • trimmers
    • generators
    • lawnmowers
    • snowblowers
  • a barbecue or portable fuel-burning camping equipment inside a:
    • home
    • garage
    • vehicle
    • camper
    • tent
  • kerosene or oil space heaters and lamps in enclosed areas unless they’re specifically designed for indoor use

Regular appliance maintenance and inspections

You can help prevent carbon monoxide with good maintenance of fuel-burning appliances.

Make sure appliances are well maintained and inspected by a professional at least once a year. This includes:

  • furnaces
  • fireplaces
  • gas stoves
  • water heaters

Home owners should regularly examine propane and natural gas powered appliances, such as:

  • stoves
  • heaters
  • refrigerators

They should be checking for:

  • leaks
  • cracks
  • blocked vents
  • improper installations
  • poor connections of gas lines to:
    • appliances
    • vents
  • breaks or tears in connection tubes
  • corroded or disconnected venting pipes

Inspect exhaust vents during and after a snowstorm to make sure they are not covered with snow. Do this for your:

  • dryer
  • furnace
  • fireplace and chimney
  • heat recovery ventilator
  • wood-burning or gas stove

Carbon monoxide alarms

Carbon monoxide (CO) can only be detected with a carbon monoxide alarm . You should have at least one CO alarm installed in your home, in addition to a smoke alarm. Smoke alarms alert you to fires, not carbon monoxide. CO alarms can be purchased at any hardware or home equipment store.

Install carbon monoxide alarms correctly

Install a carbon monoxide alarm certified by a certification body that is accredited by the Standards Council of Canada. The alarm will have a certification mark on it, such as CSA, UL, Intertek ETL etc. It will have an audible alarm to warn you of high carbon monoxide levels in your home.

Make sure to follow the manufacturer’s suggestions for:

  • installation
  • testing
  • use
  • replacement

The most important place to install a CO alarm is in hallways, outside of sleeping areas.

Test carbon monoxide alarms regularly

Test your CO alarms regularly. Replace batteries and the alarm itself as recommended by the manufacturer. Write on the battery or device to remind yourself when it was installed and when it should be replaced.

Contact your municipal or provincial government office for more information on the use and installation of carbon monoxide alarms in your area. Your local fire department may also be able to assist you.

If your carbon monoxide alarm sounds

If your carbon monoxide alarm sounds, you should do the following.

  1. do not try to locate the source of carbon monoxide
  2. leave your home immediately and move to fresh air
  3. once outside, call 9-1-1, your fire department or emergency services
  4. return to your home only after the problem has been fixed by a professional

About carbon monoxide

Carbon monoxide (also known as CO) is a gas that causes illness and can lead to death. It has no:

  • smell
  • taste
  • colour

The gas is made whenever you burn fuel like:

  • oil
  • coal
  • wood
  • gasoline
  • propane
  • natural gas

It’s also contained in second-hand smoke.

Carbon monoxide can be present in your home or cottage at any time of the year. However, the risk is greater in winter months because homes in Canada are usually heated by:

  • furnaces
  • wood stoves
  • water heaters or boilers
  • other appliances that run on fuels

These devices can release carbon monoxide into your home if they are not installed correctly, or if they malfunction.

Other sources of carbon monoxide include:

  • generators
  • charcoal grills
  • vehicle exhaust
  • cooking appliances
  • blocked chimney flues

These devices become a risk when they are used in unventilated areas, such as a:

  • home
  • garage
  • cottage
  • camper
  • tent

More information

  • The basics: protect your home and family
  • Hazardcheck virtual house tour
  • Fire Safety

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