Use of chemical air disinfectants prohibited when persons are present

Systems for continuous indoor air disinfection by atomising or gasifying disinfectants (e.g. active chlorine, hydrogen peroxide, ozone, also in situ production) into the indoor air while people are present (e.g. in classrooms, on public transport) are not approved on the basis of Art. 10 paras 2 to 4 ChemA, for the following reasons: 

• The continuous release of a disinfectant into the air contradicts the applicable minimisation requirement, which is designed to keep health risks from chemical substances as low as possible.
• Continuously atomising a disinfectant means permanently and directly exposing people present in the room to disinfectants and their reaction by-products (radicals and reaction or cleavage products). In any case residual risks remain, for example irritation of the respiratory passages and eyes, which give grounds for concern in particular in terms of protecting the health of vulnerable groups (e.g. children and adults with respiratory diseases).
• In continuous indoor air disinfection, the effect on the pathogens only sets in after several minutes. In the event of close contact, however, infectious droplets and aerosols can reach a person so quickly that disinfecting the air in this short time is not efficacious. This means that during continuous indoor air disinfection, infections in the event of close contact with an infected person cannot be prevented.
• To reduce the risk of transmission over longer distances indoors, alternative measures are available that do not lead to any additional chemicals in the room air and thus do not entail a risk to people’s health. These include regular room ventilation and special air filtration systems or air purification systems with UV-C radiation.

Against this backdrop, any offerings on the Swiss market or systems already in use for continuous indoor air disinfection systems by means of atomising chemical disinfectants while people are present are illegal.

All other systems for chemical indoor air disinfection must be authorised by the Notification Authority for Chemicals in accordance with the Ordinance on Biocidal Products (SR 813.12, OBP) before their first use (see also the document on disinfecting indoor air to combat the new coronavirus (in German, French or Italian) (PDF, 173 kB, 16.02.2022) on the FOPH website1).


Last modification 24.01.2024

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