Carbon Monoxide – BS EN 50292:2023

The British Standard BS EN 50292:2023 offers recommendations on the installation and maintenance of carbon monoxide alarms in domestic properties. Find out more about what the standard states.

Carbon monoxide is a silent killer: you can’t see it, smell it or taste it. Audible carbon monoxide alarms installed throughout a property is the only certified way to detect its presence and prevent carbon monoxide poisoning. 

What is the BS EN 50292:2023?

This British Standard is the UK implementation of EN 50292:2023. It supersedes BS EN 50292:2013, which is withdrawn. It acts as a guide on the selection, installation, use and maintenance of apparatus for the detection of carbon monoxide, intended for continuous operation in a fixed installation in domestic premises, caravans and boats. It accompanies EN 50291-1 and EN 50291-2 which is the product performance standard for domestic carbon monoxide alarms and EN50291-2:2019 which covers Carbon Monoxide Alarms to be installed in Caravans, Motor Homes and Recreational Craft.

Latest studies have shown that released CO (i.e. in a boiler room) can spread not only by diffusion through open spaces such as cable ducts, door sills or keyholes, but also by permeation through walls and ceilings throughout the entire building. The speed of permeation depends on the building materials used (wood, brick, concrete, plasterboard, etc.) and cannot generally be given as an exact value. For this reason, it is recommended that as a minimum, every room with a fuel burning appliance should be equipped with an apparatus to detect any notable exposition of CO as early as possible.

The standard states that a carbon monoxide alarm should be fitted in:

  • Rooms that contain any fuel-burning appliances (such as an open fire or gas boiler) – CO alarms may be interlinked with other alarms in the property such as smoke or heat, in accordance with EN 50291-1:2018, to ensure appropriate early warning
  • Rooms where people spend the most time – such as living rooms
  • Rooms where people sleep
  • Any room that has a flue running through it

If a fuel-burning appliance is in a room which is not used that often (such as a boiler room), the CO alarm should be interlinked to alarms in other rooms to ensures that a carbon monoxide leak can be detected from all potential sources and heard throughout the property.

EN 50292:2023

Locations unsuitable for CO alarm installation

A CO alarm should not be installed:

  •  in an enclosed space (for example in a cupboard or behind a curtain)
  • where it can be obstructed (for example by furniture)
  • directly above a sink
  • next to a door or window
  • next to an extractor fan
  • next to an air vent or other similar ventilation openings
  • where dirt and dust may block the sensor
  • in a damp or humid location – however, if there is a fuel burning appliance in e.g. the bathroom, then an apparatus suitable for humid rooms should be installed, which has a test button for regular tests
  • in the immediate vicinity of a cooking appliance

Installation in rooms with a fuel-burning appliance

EN 50292:2023

a) Ceiling mounted:

  • at least 0,3 m away from any wall, joist or ceiling fixture
  • above windows, doors, ventilation openings
  • outside the direct airflow from ventilation outlets or air conditioners.

b) Wall mounted:

  • at least 0,15 m / max. 0,3 m below the ceiling and at the same time
  • at least 0,3 m away from any other wall or fixture
  • above windows, doors, ventilation openings
  • outside the direct airflow from ventilation outlets or air conditioners.

In each case, a horizontal distance of between 1 m and 3 m from the fuel-burning appliance is recommended. For rooms divided into ceiling areas by subdivisions (joists, floor joists) with a clear height of ≥ 0,2 m, the appliance should be placed on that side of the partition or in that ceiling area, where the fuel burning appliance is located. In rooms with a sloping ceiling, the apparatus should be placed on the higher side of the ceiling.

Installation in habitable rooms without a fuel-burning appliance:

In habitable rooms and other areas (corridors, etc.) without fuel burning appliance and without an exhaust duct passing through, the apparatus should be installed as follows:

  • on a wall, in the breathing zone of the occupants present
  • the free standing installation of the apparatus in or on a piece of furniture is permitted providing the manufacturer’s instructions are followed
  • at least 0,3 m away from any other wall or fixture
  • outside any direct airflow from ventilation outlets or air conditioners

Additional things to consider

Look for a device that has been manufactured and carries a third-party approval mark (e.g. Kitemark or SGS mark) to standards BS EN 50291‑1:2018 (for domestic premises) and both BS EN 50291-1:2018 and BS EN 50291-2:2019 (for caravans and boats). These standards show that the alarms have been tested and audited to ensure their quality, including sensor reaction times, minimum alarm sound levels and temperature resistance.

Designed for installers and compliant with EN50291‑1:2018, FireAngel’s range of carbon monoxide alarms have all been calibrated and rigorously tested in-house alongside third party testing to receive certification. The new range features intelligent sensing technology, enabling the alarm’s high sensitivity mode to be activated if it predicts CO levels will increase to or above 180ppm for a rapid reaction to rising levels of CO.


*Please note: The above summary is based on FireAngel’s interpretation of BS EN 50292:2023, always refer to the standard for specific guidance