The indoor environment offers a wide variety of situations of exposure to numerous chemical and microbiological contaminants, the consequences of which on health vary, in particular according to the nature of the pollutants, the characteristics of the exposures, etc.
In recent years, the indoor air purification market has been growing with the commercialization of equipment claiming indoor air purification properties in the form of autonomous devices, as well as construction and decoration materials. highlighting depolluting properties. These devices and products are intended for the entire population, but may particularly target sensitive or sensitized subjects, such as, for example, asthmatic or allergic persons. However, the question of their effectiveness, and especially that of their harmlessness, is regularly raised.
In this context, ANSES issued an internal request to identify and analyze new techniques for purifying indoor air. The objective of this work was to assess the impact of the use of several of these devices on air quality, in other words, to analyze the pollutants actually treated, but also to identify the pollutants potentially emitted by these devices.
Agency conclusions and recommendations
The Agency recalls first of all that to reduce exposure to indoor air pollutants, it is first necessary to limit emissions at source, to ventilate and ventilate the interior spaces of buildings.
With regard to the results of its expert appraisal, ANSES emphasizes that, in general, the scientific data collected and analyzed do not make it possible to demonstrate the effectiveness and harmlessness in real conditions of use of indoor air purification devices operating on the principles of catalysis or photocatalysis, plasma, ozonation or ionization.
The Agency recommends the introduction of certification for indoor air purification devices, with the tests having to be carried out under conditions as close as possible to the conditions of use of these devices.
Concerning the specific case of sprays claiming a biocidal action, ANSES recommends, when assessing these products as part of the marketing authorization process for biocidal products, to pay particular attention to the scientific data relating the health effects linked to the inhalation of volatile organic compounds (VOC), natural or synthetic, emitted by these sprays. Indeed, several of the VOCs (terpene VOCs for example) emitted by these devices can potentially have harmful effects on health.
The question of the emission of nanoparticles by certain air purification devices, in particular those using photocatalysis, also arose during the expert appraisal. Complementary research on the emission of nanoparticles into the air by photocatalytic materials, in particular during their aging, is to be carried out, as well as the study of their harmlessness.
The Agency also recommends informing the population that the use of certain purification devices (ozonation, plasma, cold, etc.) can lead to a deterioration in the quality of indoor air following an incomplete degradation of pollutants leading to to the formation of compounds potentially more harmful than the compounds being treated.
Particular attention should also be paid to people with asthma, due to a possible aggravation of their pathology when using such devices, in particular “sanitizing” sprays or devices that can generate ozone.
Finally, the Agency emphasizes the need to conduct work on the health impact linked to the use of essential oils which may be present in many everyday consumer products.