As a result of the expertise acquired during the COVID-19 pandemic and the awareness of the importance of good indoor air quality for health, an ambitious policy is being implemented in Belgium, based on a generic and cross-cutting law: the law of 6 November 2022 (French/Dutch) on the improvement of indoor air quality in closed spaces accessible to the public (available to download here).






The law aims to improve indoor air quality in all closed spaces accessible to the public, i.e. all places enclosed by doors or walls and fitted with a ceiling or floor that are not limited to the family sphere or purely to the professional sphere.

In other words, your home and meeting rooms at the office, for example, are not affected by this law.



The law pursues four general objectives:

  1. The law defines good air quality reference levels that are indicative and not mandatory. Therefore, the law does not obligate those responsible for the spaces to provide good-quality indoor air. These references enable the quality of the air present to be assessed.
  2. The law encourages those responsible for the spaces to take the current situation into account in terms of the air quality in their premises, and to seek to improve it:
    • by measuring the indoor air quality, with a CO2 meter;
    • by carrying out a risk analysis describing the premises and the activities taking place there and making an inventory of possible sources of indoor air pollution and the air treatment systems present and used (ventilation and air purification equipment); and
    • by implementing an action plan describing the actions envisaged with the aim of implementing an approach, possibly in stages, to improve indoor air quality.
  3. The law ensures transparency with regard to the people who frequent an establishment as to the level of indoor air quality that can be guaranteed, through the introduction of a certification and labelling system. With this system, each space will be assigned a label that must be displayed at the location. This label will inform the general public that the indoor air quality is being measured and controlled in the space in question, in order to minimise the negative impact the air could have on people's health.
  4. The law creates a platform on indoor air quality to broaden the existing scientific knowledge, advise policymakers and raise public awareness, through collaboration between relevant industries, the authorities, manufacturers and installers of ventilation and air purification devices, the scientific community, etc.

You can find the all the reasoning behind the law in the explanatory statement (French/Dutch).



The law establishes two reference levels that enable the indoor air quality to be assessed. There is no obligation to reach these levels, but they can be used as a target by those responsible for the spaces when investing in ventilation and/or air purification systems:

Reference Level A:

  • the concentration of CO2 in a room is less than 900 ppm (which means that CO2 represents 0.09% of the volume of the air considered), or
  • the minimum ventilation and air purification flow rate is 40 m3 per hour per person, including at least 25 m3 per hour per person of ventilation with outside air.

Reference Level B:

  • the concentration of CO2 in a room is less than 1,200 ppm (which means that CO2 represents 0.12% of the volume of the air considered), or
  • the minimum ventilation flow rate with outside air is 25 m3 per hour per person.

The higher the ventilation flow rates, the higher the air replacement and so the lower the concentrations of viruses and other pollutants in the room.
As CO2 is exhaled by the people present, it accumulates in the room if it is not sufficiently ventilated. The measurement of the CO2 concentration in the air is therefore an indicator of the air replacement rate in the room.

These reference levels correspond to air quality standards of the Code of well-being at work (Codex) (French/Dutch). Certain spaces subject to the codex are therefore obligated to meet these standards.


The law on indoor air quality provides a framework, which is gradually being supplemented by Royal Decrees. These RD define the practical details of the obligations for the spaces concerned.

To date, there is no obligation for the operators and owners of the spaces.

From 1 October 2024, all closed spaces accessible to the public that wish to implement the law on a voluntary basis will have to:

  • use at least one CO2 meter;
  • draw up a risk analysis;
  • draw up an action plan, if the risk analysis shows that this is necessary;
  • at the request of the public, provide information on the actual or expected air quality in the place.
Would you like more information on how to apply this legislation?
  • Read the Royal Decree of 12 May 2024 (FR, NL) determining the procedures referred to in Articles 3 and 4 of the Act of 6 November 2022;
  • Read the practical guide (FR, NL) to choosing, installing, using and maintaining an air quality meter (CO2 meter);
  • A practical guide to help you develop a risk analysis and action plan will be available by October 2024. An application will also be created to enable you to complete these documents online;
  • See the FAQ.

In future, it will be compulsory for all closed spaces accessible to the public to: 

  • use at least one air quality meter;
  • develop a risk analysis;
  • develop an action plan, if the risk analysis shows that this is necessary;
  • apply for certification of the space;
  • display the certification label as soon as it is awarded by the FPS, and
  • continue to operate the space under technical conditions at least equivalent to those existing at the time of certification.

These obligations will come into force in stages.

  1. Initially, only the first three points above will be concerned. They will become mandatory from 1 January 2027. Initially, these obligations will only apply to certain closed spaces accessible to the public. The scope will then be extended to cover all spaces by the end of 2037.   
  2. In a second phase, spaces that apply the initial provisions will be able to implement the following three points. This will initially be done on a voluntary basis, once the certification process has been set up. These provisions will then become mandatory, at the earliest on 1 January 2038, i.e. once all closed spaces accessible to the public are covered by the first obligations.

The timetable for the entry into force of these obligations is set out in the law of 18 May 2024 (FR, NL) containing various provisions relating to health and finance (article 8).

This page will be updated as and when the decrees implementing the law of 6 November 2022 are published.

The guidance on ventilation made during the COVID-19 pandemic continues to be recommended by the authorities. Read the guidance here.


  • Any companies and organisations that employ staff must comply with the Code of well-being at work (or Codex), which sets air quality standards in terms of CO2 concentration thresholds and ventilation rates.
    Further information: Code of well-being at work (French/Dutch)
  •  Products placed on the market must meet health and environmental quality requirements defined as part of the legislation on product standards. Requirements concerning air purification systems and CO2 meters are defined on this basis.
    Further information: Product standards law (French/Dutch)

Would you like more information?