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Carbon monoxide expert , we have been engaged in the field of security for more than ten years. Now we will share experience and personal opinions with readers by writing articles, hoping to help readers.

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detailed information about carbon monoxide and how to prevent it

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Carbon monoxide is a colorless, odorless gas that has received attention because it is imperceptible and can easily bind to human hemoglobin, causing carbon monoxide poisoning. Carbon monoxide come from any fuel produced by cars, fireplaces, charcoal, grills, water heaters, gas appliances, etc. These items usually don’t cause any problems, but if used incorrectly or not properly installed, they can produce and accumulate carbon monoxide in a closed environment. Therefore, this blog mainly conducts a comprehensive analysis of carbon monoxide gas, and proposes corresponding solutions based on its generation and harm to reduce the occurrence of carbon monoxide poisoning.

1. What is carbon monoxide gas

Carbon monoxide is a colorless, odorless, tasteless, flammable gas which is produced by Incomplete combustion of carbonaceous materials. From chemical formula, it is made up of one carbon atom and one oxygen atom connected by a triple bond. Thats why people also call it as CO.

1.1 Features

Lighter than air: At room temperature and atmospheric pressure, carbon monoxide is a gas with a density of 0.967 grams per liter. It is slightly less dense than air (0.1% less), meaning that carbon monoxide (co) is not heavier but lighter than air. And since CO is slightly lighter than air, and doesn’t like smoke in a room that rises to the ceiling, CO mixed itself with warm, rising air and quickly spread everywhere in the room. We are breathing CO gas without even noticing.

Tips: For a detailed information about the place of installing carbon monoxide detector please click here.

Inorganic: Organic substances contain carbon, but substances containing carbon in their composition are not necessarily organic. Such as carbon monoxide, carbon dioxide, carbonate, etc. are all inorganic substances.

Unvisible: Carbon monoxide cannot be seen, touched, heard, smelled or felt. It can only indirectly reflect the existence of carbon monoxide around. The most direct and effective method is to install a carbon monoxide detector, which will alarm when the surrounding carbon monoxide concentration reaches a dangerous value to give people enough time to escape. By the way, carbon monoxide can not travel through walls unless the wall has several gaps or huge holes.

1.2 Difference between CO and CO2

Many people also mention CO2(carbon dioxide) when they talk about CO(carbon monoxide), however, there are not the same. In terms of chemical equations, they differ by only one element of oxygen, Essentially, they are two completely different gases. Carbon dioxide is also a colorless and odorless gas. It is produced by the burning of fossil fuels and wood. The main difference between it and carbon monoxide is that it is non-toxic, but its emissions have an important impact on environmental pollution. It can cause the rise of annual sea levels and global warming.

2. Why is carbon monoxide dangerous

2.1 Flammable

Pure carbon monoxide is a highly flammable gas that can easily ignite when the temperature reaches 199.4 degrees Fahrenheit or 93 degrees Celsius. In addition, if carbon monoxide combines with air to form a mixture, it will determine whether it will explode according to the concentration ratio of carbon monoxide and air in the mixture. When the carbon monoxide to air concentration ratio is in the range of 12.5% to 80%, the mixture will explode when burned; when it is lower than 12.5%, it will neither explode nor catch fire; when it is higher than 80%, it will not explode but catch fire. Therefore, carbon monoxide is a flammable and explosive gas.

At home, the common sources of carbon monoxide are mainly gas in the kitchen and equipment such as heaters. Before using gas, it is best to test the gas in the tank, because pure carbon monoxide is very flammable. For heaters, since the heating temperature generally does not exceed 199.4 degrees Fahrenheit or 93 degrees Celsius, as long as there is no gas leakage, there will be no combustion or explosion.

2.2 Poisonous

Carbon monoxide gas is harmful to people due to its poisonous. This is because carbon monoxide can easily combines with hemoglobin in human blood, rendering it incapable of transporting oxygen to organs and causing people to die of hypoxia. In addition, Since CO is colorless, odorless, tasteless gas that you simply could not sense it until the real symptoms come out. Here to show you the different levels of carbon monoxide concentrations varying degrees of symptoms, including dizziness, fatigue, inability to move, hallucinations and even death.  

50ppmthe maximum concentration that healthy adults can bear within 8 hours
200 ppm2 ~ 3 hours, slight headache and fatigue
400 ppmForehead pain within 1 ~ 2 hours; Life threatening after 3 hours
800ppmDizziness, nausea and spasm within 45 minutes; Loss of consciousness within 2 hours; Died within 3 hours
1600ppmHeadache, dizziness and nausea within 20 minutes; Died within 1 hour
3200ppmHeadache, dizziness and nausea within 5 ~ 10 minutes; Died within 30 minutes
6400ppmHeadache, dizziness and nausea within 1 ~ 2 minutes; Died within 10 ~ 15 minutes
12800ppmDied within 1 ~ 3 minutes

As we can see from the chart, the normal carbon monoxide level that healthy adult can accept is no more than 50 ppm, once the concentration of carbon monoxide level reaches over 200 ppm, it can be called dangerous carbon monoxide level. When the carbon monoxide concentration reaches 200ppm, people will experience headache symptoms, which feel a bit like a mild cold, but not cause people’s attention. When the concentration is higher and higher, the symptoms of headache intensify, breathing difficulties, more and more sleepy, gradually lost consciousness, and finally died in deep sleep. This is because high concentrations of carbon monoxide can quickly combine with hemoglobin, causing people to die from extreme hypoxia within 1 hour or even 3 minutes. The above conditions are for healthy adults, but if the elderly or children or sick people are exposed to carbon monoxide, symptoms may be more severe.

While normal people can withstand 50ppm carbon monoxide for up to 8 hours, carbon monoxide detectors do not allow people to do so. To keep people safe enough, carbon monoxide detectors that meet the latest CE standards must give an alarm after 2 hours when the surrounding carbon monoxide concentration reaches 30ppm, giving people enough time to move outside. When the monitoring of the surrounding carbon monoxide concentration reaches 50ppm, the detector will give an alarm after 1 hour. If you think the detector is making a false alarm, you can also check the detector readings to confirm your guess. For more information on the must-have features of carbon monoxide detectors, click here.

2.3 Silent killer

As mentioned above, carbon monoxide cannot be sensed. If someone is unfortunate to be exposed to carbon monoxide in his sleep, he will die in his sleep due to the accumulation of carbon monoxide in his body, which leads to prolonged hypoxia, so it is called the silent killer. However, pets can sense the uncomfortable symptoms of carbon monoxide in advance. It turns out that pets are better at perception than people, so when there’s carbon monoxide around, dogs get irritable and bark, and cats stick to doors and windows and keep trying to escape.

3. What to do while carbon monoxide poisoning

If a family member is found to have carbon monoxide poisoning, the most common method is to immediately open the surrounding windows and doors, then quickly take the family member outside, and finally call 911 for help, and cannot enter the house until a professional person arrives.

Carbon monoxide poisoning can be treated quickly if it is mild which means that carbon monoxide poisoning can be reversed if it is not serious. It is critical to remove the patient from the poisonous environment as soon as possible and allow them to breathe fresh air, which can promote the rapid slowing and disappearance of symptoms. After implementing the aforementioned measures, you should be able to recover completely within a week, with no sequelae or recurrence.

When carbon monoxide poisoning is moderate or severe, it is accompanied by relatively strong discomfort symptoms. At this time, symptomatic treatment should be administered as soon as possible in order to get out of the poisonous environment. The best treatment for carbon monoxide poisoning is to be hospitalized, and be treated with high-concentration oxygen inhalation. Treatment for symptoms is required; otherwise, cerebral edema, pulmonary edema, and severe myocardial damage will occur. This may take 2-3 weeks to heal and may result in complications. However, you don’t need to worry about carbon monoxide poisoning can cause cancer, the fact that it doesn’t exist, it just increases your risk of heart disease.

4.How is carbon monoxide produced and available in home

Carbon monoxide is produced by the incomplete combustion of carbonaceous materials. On the one hand, it is caused by the needs of human life, such as the need to use a water heater for heating, driving, etc., on the other hand, it involves chemical reactions. Carbon-containing substances burn in an environment with sufficient oxygen to produce carbon dioxide while in an environment with insufficient oxygen to produce carbon monoxide.

Carbon monoxide is more likely to be formed in the house and attached garages with fuel equipment which are as follows.

Stovetops and kitchen stoves: This is one of the main sources of carbon monoxide. About 800ppm of carbon monoxide is produced in the kitchen, if there is no good ventilation or a range hood, it will easily lead to the accumulation of carbon monoxide in the kitchen.

Fireplace: Fireplaces are more common in European countries, and people use it for heating in winter. Some families do not have a fireplace, but use a wood stove instead. When using it, you need to pay attention to the smoothness of the ventilation pipe. Because smoke from burning wood can easily build up in your home, increasing the concentration of carbon monoxide in the air, be sure to open the chimney pipe when using a fireplace.

Grill: People prefer to grill with charcoal because it makes the food taste more natural. However, be sure not to grill in a closed environment, because burning charcoal will consume oxygen in the environment. If charcoal is burned in an environment lacking oxygen, it will produce carbon monoxide concentrations as high as 1000ppm within 2~3 minutes, which is very dangerous concentration.

Water heaters and heaters: The carbon monoxide in the heater is mainly present in the exhaust gas. No exhaust pipe is installed, no hard pipe is used as the connecting pipe of the gas water heater, and the exhaust gas monitor is inaccurate, etc., which may cause the exhaust gas to be discharged into the room or be blocked in the ventilation pipe, resulting in the accumulation of carbon monoxide and the accumulated carbon monoxide concentration is as high as 1600ppm .

Clothes dryers: Instead of just pumping out carbon monoxide, electric dryers come with a lot of moist air and lint coming out of the dryer, which can seriously damage your home if they build up. Therefore, every electric clothes dryer must have an outlet through which warm, moist air escapes, or it won’t work properly. In addition to this, the air is often full of lint, which, if not vented outside, can cause all kinds of problems, like moisture can rot the frame and encourage mold growth, and lint can catch fire.

Portable generators: Generators are usually placed outdoors, at least 20 feet from the house. It is known for its ability to produce carbon monoxide concentrations in excess of 1000ppm in a short period of time, which means that if you use a generator in your home, you could be dead within minutes. More data show that the amount of carbon monoxide produced by the generator is equivalent to the amount produced by 450 cars.

Motor vehicles: Many houses have attached garages which is also a hidden danger of carbon monoxide buildup. On the one hand, starting a car without opening the garage door is equivalent to starting the engine in a closed environment, which produces about 1000ppm of carbon monoxide; on the other hand, car exhaust is composed of carbon monoxide, carbon dioxide, hydrogen sulfide and other gases. Starting a car in a closed environment will not only increase the temperature in the garage, but also easily cause the accumulation of exhaust gas.

Tobacco: Tobacco is also one of the causes of carbon monoxide. The gas in cigarettes is directly inhaled into the lungs of the human body, which means that the smoker has a carbon monoxide concentration of 20 ppm in the body. Although it is not fatal, if you continue to smoke for a day, the concentration of carbon monoxide in the body will increase.

5. How can we detect carbon monoxide gas

5.1 Symptoms of equipment when leaking gas

It is critical to check the ventilation ducts and maintain the gas equipment on a regular basis. You should be cautious if the fuel appliance has any of the following conditions.

  • Soot strips around fuel-burning appliances, or in fireplaces
  • No upward airflow in the chimney
  • Excessive moisture and condensation on windows, walls and cold surfaces
  • Rust on flue or electrical jack
  • Orange or yellow flame in burning appliance (flame should be blue)
  • Damaged or discolored bricks at the top of the chimney

5.2 Abnormal behavior of people

In addition, co can also be indirectly inferred from the abnormal behavior that people show when carbon monoxide poisoning. For example, when people show signs of weakness, drowsiness, paleness, and the possibility of falling down at any time, please open the window immediately and take him outside to breathe oxygen.

6. Install carbon monoxide detector

Installing a carbon monoxide detector is recognized as the most efficient and fastest way to detect carbon monoxide gas. The following content will be expanded by the installation type, installation location, installation quantity, and test detectors of carbon monoxide detectors.

6.1 What the type of detector should I need to install

When installing detectors in your home, it’s important to know which type of detector you need in each room. For example, bedrooms need carbon monoxide detectors, and kitchens need smoke alarms and carbon monoxide detectors.The picture below is a suggestion for what type of detectors to install in a room in a house, if you want to get more details, you can refer to this.

6.2 How many detectors should I need in the house

Carbon monoxide alarms should be installed on every floor of your home, including the basement. It needs to be installed inside every bedroom and outside every sleeping area. For example, a three-bedroom, two-story home should have at least seven carbon monoxide alarms. Homes with a certain number of hardwired alarms can still place additional battery-operated smoke alarms throughout the house. If there are not many smoke alarms in the house, just install it in the key areas of the bedroom, kitchen and bathroom.

6.3 How to test carbon monoxide detectors at home

6.3.1 Test with bottled carbon monoxide gas

This is a bottled spray that can be bought in most furniture repair shops and can be purchased online. The price of each bottle is 8~15 dollars, which can be used for several years.

6.3.2 Test with a long match or wooden kebab

The principle of this method is to ignite one end of the match and then put it into a closed space for combustion. The object needs oxygen for combustion. When the object burns in a closed environment, the oxygen inside will be exhausted. At this time, the combustion lacking oxygen belongs to incomplete combustion and will produce high concentration carbon monoxide (even if the object is very small).

6.4 Why is carbon monoxide alarm going off

There are 3 main situations in which carbon monoxide beeps: the presence of carbon monoxide gas is detected, the low battery alarm and the detector reaching end of life. The beeps of each detector convey different meanings, so refer to the alarm’s user manual for the specific model. E.g:

4 beeps and a pause: The alarm has detected carbon monoxide in the air, please evacuate the house as soon as possible and call the police

1 beep every minute: This means the battery is low, please replace the battery in time

5 beeps every minute: This means the detector has reached the end of its life, please replace it with a new one

6.5 What does a carbon monoxide alarm sound like?

Generally, carbon monoxide alarms make a loud beeping noise when they detect the presence of carbon monoxide. The sound of the alarm is a very high-pitched, piercing beep that keeps your attention with an 85-decibel tone,like bibibibi. This beeping noise is designed to wake you up and alert you to the danger so that you can take action to protect yourself and your family.

7.Laws and regulations across the UK


The law in Scotland has changed and as of 1 February 2022. It shows that if you have a carbon-fuelled appliance, like a boiler, fire, non-electric heater or flue you must also have a carbon monoxide detector. This does not need to be linked to the fire alarms.

If the carbon monoxide alarm is battery operated, it must have a sealed battery for the duration of its lifespan, which may be up to 10 years. And you need to check that each alarm complies with the standards – Carbon monoxide detectors: British Kitemark EN 50291-1:2018.


Carbon monoxide alarms are mandatory for all homes in Northern Ireland installing new fossil fuel equipment following changes to the building Regulations (Northern Ireland) 2012 came into operation on 31 October 2012.


Renting Homes (Wales) Act 2016 will change, effective from 15th July 2022. The new legislation aims to ensure that private and social rental properties in Wales are fit for human habitation, including the provision of appropriate fire and carbon monoxide alarm systems.

From July 15, 2022, landlords will have to ensure that there is a working, repaired carbon monoxide alarm in every room of the property, which contains a gas appliance, oil burner or solid fuel burner.


The Smoke and Carbon Monoxide Alarm (England) Regulations 2015 have been approved by Parliament and will come into force as planned on 1 October 2015. From 1 October 2015, private sector owners are required to install at least one smoke alarm on every floor of their property and carbon monoxide alarms in any room equipped with solid fuel burning appliances such as coal stoves, wood stoves.  

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