Every year in France, approximately 3,000 people are accidentally poisoned by carbon monoxide, and about 100 die as a result. This gas is particularly dangerous because it is invisible, odorless, non-irritating, and undetectable. Within minutes, severe poisoning can lead to a coma or even death.

Multiple and often preventable causes

CO poisoning most often results from improper use of appliances or lack of maintenance of systems. The main identified causes are:

• Appliances connected to a flue (boilers, water heaters, stoves, or fireplaces) that are poorly maintained or improperly adjusted;

• Improperly used portable appliances: space heaters, braziers, barbecues, generators, or water pumps, and other appliances equipped with an internal combustion engine;

• Motor vehicles (particularly cars) with the engine running in an unventilated space such as a garage;

• Appliances that run on fuels such as gas, wood, coal, fuel oil, butane, propane, gasoline, or kerosene.

Best practices to minimize risks

In the home, it is essential to have heating systems, hot water systems, and flues inspected and maintained at least once a year and before any restart by a qualified professional. This applies to both primary residences and second homes.

It is also necessary to ventilate rooms for at least ten minutes a day, even in cold weather, to ensure regular air exchange. Ventilation systems (mechanical ventilation, air vents, grilles) must be kept in good working order and must never be obstructed.

For portable heating devices, follow the manufacturer’s instructions, use only the recommended fuel, and operate a space heater for no more than two consecutive hours. Cooking appliances (stoves, ovens, gas burners) must never be used for heating.

Similarly, generators, braziers, and barbecues must never be used in an enclosed space (home, garage, basement, RV, etc.) or placed near doors, windows, or vents. In the event of a flood or storm, it is imperative never to use internal sump pumps, water pumps, or generators with internal combustion engines indoors.

As for vehicles, never leave them running in an enclosed space (especially cars).

Recognize the symptoms and act quickly

The first signs of poisoning often include headaches, extreme fatigue, nausea, vomiting, or dizziness. These symptoms should serve as a warning, especially if they appear rapidly in the presence of combustion devices and affect several people or pets simultaneously in the same location.

If poisoning is suspected:

• Immediately ventilate the room by opening doors and windows;

• Turn off combustion appliances if possible;

• Evacuate the premises immediately;

• Call emergency services: 15 (Samu), 18 (fire department), 112 (European emergency number), or 114 for the hearing impaired, or a poison control center at 01 45 42 59 59 (emergency number available 24/7). The person’s condition may require hospitalization.

A renewed information campaign

These simple and essential steps are outlined in the brochure “Protecting Yourself from Carbon Monoxide Poisoning.”

In addition, the program Consomag, produced by the National Institute of Consumer Affairs (INC) in partnership with the Directorate General for Health, has been broadcasting these prevention messages on France Télévisions channels since November 10, 2025. The program is also available online on the Consomag website.

A brochure is also available to the general public: The Dangers of Carbon Monoxide. Understanding the Risks.

For more information:

• Ministry of Health, Families, Autonomy, and People with Disabilities

• Public Health France Information Resources