All you need to know about carbon monoxide (CO)

What is carbon monoxide?

Carbon monoxide, also known as CO, is a highly toxic gas that is fatal in large doses. Odorless and invisible, it is generated by the improper combustion of fossil fuels. CO spreads rapidly through the air. It enters the lungs, reducing the oxygen supply to vital organs.

Be careful not to confuse it with CO2. Carbon dioxide (CO2) is a non-toxic gas. It plays an essential role in the respiration of living beings and in the vital processes of plants.

Where does carbon monoxide come from?

In France, carbon monoxide poisoning affects almost 3,000 people a year. This dangerous gas is potentially fatal to humans, so it’s important to identify the source of its emission. In winter, the risks of carbon monoxide poisoning increase. CO can come from :

• Oil, coal, gas and wood-fired heating equipment;
• Individual gas boilers ;
• Gasoline-powered tools and appliances such as lawnmowers and brushcutters;
• Outdoor equipment such as barbecues, oil lamps, stoves ;
• Gas appliances such as oven, stove or space heater;
• Vehicles with internal combustion engines…

Here are some examples of situations where carbon monoxide may be emitted:

Unmaintained or defective equipment

• An unmaintained chimney;
• An incorrectly adjusted gas boiler;
• A faulty stove.

Equipment or vehicles used in an enclosed area

• Starting a car in a garage;
• Starting up combustion tools in a shed.

Inappropriate use of equipment

• Use of a grill or barbecue in the home;
• Prolonged activation of auxiliary heating.

During the winter months, these appliances are in high demand, so regular maintenance is highly recommended to ensure the safety of your home. It is important to have these devices checked by qualified professionals. Checking these devices will significantly reduce the risk of carbon monoxide poisoning.

How does carbon monoxide affect health?

A little science

In its normal state, hemoglobin, a constituent of red blood cells, is charged with oxygen. In the event of intoxication, carbon monoxide (CO) binds to this hemoglobin and replaces oxygen with a new molecule called carboxyhemoglobin. The lack of oxygen then causes general cell dysfunction.
This asphyxiating gas spreads rapidly through the air and can be fatal within an hour!
In women, during pregnancy, carbon monoxide can cross the placental barrier. Because of CO, the fetus is no longer safe, and may be in grave danger. In fact, it can cause serious neurological sequelae or death.

The effects of CO on humans

The effects of carbon monoxide vary according to :

• The amount of carbon monoxide in the air ;
• Duration of exposure ;
• The person’s sensitivity and state of health.

At low levels of exposure, the victim may experience headaches, nausea or fatigue.
At medium exposure, headaches are persistent. Feelings of dizziness, lightheadedness and blurred vision appear. The person becomes drowsy and their heart rate increases.
At high exposure, the individual feels very weak. The latter may faint or even convulse. If no action is taken, the victim risks coma or even death.

What to do in case of poisoning?

Poisoning can affect several people in the same household. If you have a carbon monoxide detector, it will sound when CO is present. At the first signs of intoxication-related weakness, you need to act fast.

Adopt the right gestures:

1 – Switch off the power supply to the CO
2 – Evacuate the premises
3 – Call for help by dialing 18, 15 or 112 (114 for the hearing-impaired).

Do not return to your home without being asked to do so by the emergency services.

Prevent the risks of poisoning

Throughout the year, it’s important to maintain the appliances in your home to avoid CO poisoning. There are a few rules to follow:

• Ventilate your home for at least 10 minutes a day (even in winter) to improve indoor air quality;
• Minimize prolonged use of auxiliary heating systems;
• Checking and maintaining household appliances;
• Keep CMVs and other air inlets/outlets clear;
• Follow the manufacturer’s instructions for combustion appliances.

Carbon monoxide is dangerous and toxic. To prevent this risk, we strongly recommend fitting a carbon monoxide detector (COD) to your home or room. This will emit an audible signal to alert occupants to the presence of CO in the room.