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, e.g. 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 achieve indoor air quality corresponding to the reference levels.
  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, and the scientific community.

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.
The measurement of the CO2 concentration in the air is 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 constitutes a framework that does not create direct obligations for the sectors affected by its application. It must be supplemented by royal decrees that define the practical details of these obligations.

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

In the future, for each closed location accessible to the public, it will be necessary to:

  • use an air quality meter;
  • develop a risk analysis and action plan and make them available;
  • apply for certification;
  • display the certification as soon as it is awarded by the FPS, and
  • continue to operate the site under technical conditions at least equivalent to those in place at the time of certification.

This page is updated as these decrees 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 devices and CO2 meters are defined on this basis.
    Further information: Product standards law (French/Dutch)

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