Indoor Air Quality Guidelines (IAQGs)

Until recently, the quality of air inside buildings was not a major health concern, as outdoor air quality had been. Yet, in temperate climates we spend on average 85% of our time in enclosed environments, and a majority of that time in the home. Indoor air pollutants can have various different sources. In recent years, this subject has received increasing attention with, in particular, the French government’s creation of the French Indoor Air Quality Observatory (OQAI) in 2001.

Many measurement campaigns in indoor environments have thus been conducted, particularly in housing and public buildings such as schools or day-care centres, but also in less obvious places such as swimming pools, gyms, etc. To properly interpret the results from measurements of indoor air, reference values are needed that enable a comparison of the levels observed in relation to health criteria. Yet for many pollutants, there are not enough data available to allow scientists to establish reference values ​​for humans, which limits their ability to estimate the impact of indoor air pollution on the health of the population.

This led the Agency to issue an internal request in 2004 with a view to formulating indoor air quality guidelines (IAQGs).

To carry out its expert appraisal, ANSES proposed an IAQG development method that was most recently updated in 2016 (from an initial report of 2007 updated in 2011). In light of the experience it has gained in this subject since 2004, ANSES has proposed adapting its IAQG development method (PDF) (in French) (in French).

In the first place, when ANSES develops IAQGs, it takes into account the work by the World Health Organisation (WHO) specifically on indoor air. It carries out a critical analysis of the indoor air quality guidelines proposed by the WHO. 

Development of IAQGs is mainly based on:

• the description and analysis of the health effects associated with the pollutants via exposure to air. This involves drawing up a toxicological profile for each substance;
• the choice of critical effect and mechanism of action to be considered; 
• a summary of the quality guidelines and toxicity reference values (TRVs) available in the literature;
• the proposed IAQGs that are able to be established according to the methodological guidelines published by ANSES, when deemed necessary.

In addition, the IAQGs proposed by ANSES are now accompanied by an analysis of the measurement methods available, guidance on the sampling strategy and on how to place the established values into perspective, the identification of risk situations and a proposal, when available, of information enabling the health benefits associated with compliance with the IAQG to be quantified.

A dozen pollutants of interest in indoor air have been appraised by ANSES with regard to the IAQGs. ANSES's opinions and expert appraisal reports can be downloaded by clicking on the pollutants below (in French):

• Formaldehyde (PDF)
• Carbon monoxide (PDF)
• Benzene (PDF)
• Naphthalene (PDF)
• Trichloroethylene (PDF) and the addendum to the report (PDF)
• Tetrachloroethylene (PDF) and the addendum to the report (PDF)
• Particulate matter (PDF)
• Hydrocyanic acid (PDF)
• Nitrogen dioxide (PDF)
• Acrolein (PDF)
• Acetaldehyde (PDF)
• Ethylbenzene (PDF)
• Toluene (PDF)

The values proposed for these pollutants are summarised in the table that can be downloaded at the following link:

> View the summary table of published IAQGs (PDF)

The IAQGs proposed by ANSES are the initial basis of the institutional process that seeks to establish regulatory values for the monitoring of indoor air quality. They are based solely on health criteria and are for information only.

To support the public authorities in establishing operational values to enable measures to be implemented to improve indoor air quality, the Ministry of Health asks the French High Council for Public Health (HCSP) to propose management support reference values for air in confined spaces, based on ANSES's IAQGs, along with a timetable for their deployment. The HCSP formulates proposals to inform risk managers of the concentration levels from which measures should be undertaken. In doing this, it takes account of practical, regulatory, legal, economic and sociological considerations.

Lastly, in accordance with the Act of 1 August 2008 on environmental liability, regulatory IAQGs are established by the Ministry of Ecology, included in the French Environment Code and associated with enforceable management measures. To date, indoor air quality guidelines have been defined for formaldehyde and benzene.

Monitoring of indoor air quality is being implemented gradually, particularly for establishments accommodating children (Article R221-3 of the Environment Code)[1],and is based on:

• a mandatory assessment of the condition of the aeration and ventilation systems[2] very 7 years. Assessing the condition of the aeration and ventilation systems consists in noting the presence of openings to the outside, their ease of access and manoeuvrability, as well as a visual examination of the air vents or grilles. It is carried out by the individuals or organisations mentioned in this same decree, mainly the technical departments of the local authority
• the implementation of either:
• a measurement campaign for certain pollutants (formaldehyde, benzene, carbon dioxide and tetrachloroethylene if the establishment adjoins a dry-cleaning facility), which must be carried out by accredited organisations.
• self-assessment of indoor air quality using a practical guide for better indoor air quality in places accommodating children, enabling an action plan to be drawn up for the establishment.

The first deadlines for implementing this monitoring have been established on 1 January 2018 for collective facilities hosting children under 6 years of age, nursery schools and primary schools, and then on 1 January 2020 for recreational facilities, and secondary education or vocational training establishments[3].

To date, regulatory indoor air quality guidelines have been defined[4] for formaldehyde and benzene. Other values have also been defined where further investigations should be carried out and for which the Prefect of the département where the establishment is based must be informed.

[1]Decree No. 2011-1728 of 2 December 2011 and Decree No. 2015-1000 of 17 August 2015
[2]Decree No. 2015-1926 of 30 December 2015
[3]Decree No. 2012-14 of 5 January 2012
[4]Decree No. 2011-1727 of 2 December 2011