Carbon monoxide alarms

there are no precise technical requirements for carbon monoxide alarms in the Finnish legislation. Carbon monoxide alarms usually meet the requirements laid down in the standard SFS-EN 50291-1.

Carbon monoxide alarms are not prescribed as compulsory for properties, but it is recommendable to install them in rooms in which any fuel-driven apparatus is being used.

A carbon monoxide alarm

  • reacts to raised levels of carbon monoxide (CO) in the air
  • reducing the risk of carbon monoxide poisoning.

Carbon monoxide is an odourless, tasteless, colourless and poisonous gas that cannot be detected by humans. Carbon monoxide is produced by incomplete burning of carbon-based fuels such as petrol, oil, wood or natural gas in low-oxygen conditions.

People die every year in Finland from carbon monoxide poisoning. Most of these accidents take place in caravans, mobile homes and holiday cabins. Breathing in carbon monoxide causes chemical asphyxiation and the resulting oxygen deficit can quickly lead to death.


Make sure you install the carbon monoxide alarm in the correct position as carbon monoxide is only slightly lighter than air and does not necessarily rise directly towards the ceiling in situations where there may be various airflows in the building. The speed at which carbon monoxide rises is affected by its temperature. Warm gas rises faster than cold gas.

Carbon monoxide alarms must not be used in the place of statutory smoke alarms and are not intended to cover for any neglect of maintenance and servicing or appropriate installation of any potential sources of carbon monoxide.

How to place a carbon monoxide alarm

  • Place the alarm in a room with a fuel-powered appliance, such as a fireplace, gas cooker or other fuel-burning appliance.
  • Make sure that the sound of the carbon monoxide alarm can be heard in areas where people spend time in the property.
  • If you mount the alarm on the ceiling place it at least 300 mm away from walls.
  • Combined smoke and CO alarms should be mounted on the ceiling.
  • Note that if the alarm is mounted on the wall, it should be at least 150mm from the ceiling, because air may stagnate in the corner of the wall and ceiling.

Follow the above instructions even if they contradict the instructions of the device.


Do not install a carbon monoxide alarm

  • outside a building;
  • in a enclosed space, such as in or under a cupboard;
  • where it can be obstructed (e.g. by furniture or curtains);
  • directly above a sink;
  • next to a door, window or extractor fan or in other position where it can be subjected to strong airflows;
  • next to a ventilator or other similar vent hole
  • in wet or humid areas, such as bathrooms or shower rooms;
  • in the direct vicinity of or above a kitchen cooker or cooking plate.