Manufacturers, sellers and importers of CO2 meters must meet various criteria for their devices for public spaces to be authorised for sale.

In parallel with the preparation of the
draft law on improving indoor air quality in closed spaces accessible to the public, ministerial decrees have set standards for air purification installations and CO2 meters 

A ministerial decree set the conditions for the placing on the market of CO2 meters. It also specified that devices that meet all the above criteria may be labelled "device suitable for use in the fight against SARS-CoV-2" directly on the device, its packaging or in the technical manual. 

This ministerial decree is no longer in effect as of 30 September 2022. 

To ensure quality indoor air and limit the propagation of aerosols, the Superior Health Council recommends that the CO2 level in indoor air be lower than or equal to 900 ppm.


  1. They measure CO2 directly or meet standard EN 50543;
    This standard concerns the fast and accurate measurement of carbon monoxide and carbon dioxide in the environment. CO2 meters must measure the CO2 concentration accurately in accordance with this standard. CO2 meters that estimate the CO2 concentration based on other gases or substances in the air do not meet these requirements unless it can be demonstrated that these sensors meet the requirements of EN 50543. 
  2. They cover CO2 concentration measurement ranges from 0 to at least 2,000 ppm;
    CO2 meters must be designed to measure this CO2 concentration range correctly.
  3. They are designed to be recalibrated to compensate for measurement drift in accordance with the procedures laid down by the manufacturer in the instrument's technical manual;
    For technical reasons, a CO2 meter does not remain stable over a long period. The measurement gradually deviates from the real value. The device must therefore be recalibrated according to the manufacturer's procedure. This requirement does not apply to CO2 meters with a self-calibration system.
  4. They measure a CO2 concentration with an error of a maximum of 10% of the measurement. Example: a 10% error on a displayed value of 900 ppm corresponds to ± 90 ppm. This means that the actual value is between 810 and 990 ppm;
    The 10% threshold is the allowable error. Every measuring device has a measurement error.

    When purchasing CO2 meters, it is advisable to remain cautious and be wary of devices sold at very low prices which could have error margins higher than the 10% allowed.
  5. They are supplied with a technical manual that specifies the installation conditions for correctly measuring the CO2 concentration in a given space.   

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