HEPA filters in classrooms: a new weapon against sick days?
NCT ID NCT07119333
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This study tests whether placing HEPA air purifiers in primary school classrooms can reduce student absences caused by respiratory infections like colds and flu. About 72 schools in Norway will be randomly assigned to receive either working purifiers or sham devices. Researchers will track absences over 12-week periods during two winter seasons to see if cleaner air keeps more children in class.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Air purifiers with HEPA filters
- What this could lead to
- If effective, air purifiers could become a simple, non-disruptive way to reduce school absences and limit the spread of respiratory infections in classrooms.
- What could go wrong
- This is an early-stage trial with only 72 schools, and the sham control design means results may be modest. Air purifiers might not significantly cut absences, and the study focuses on a specific age group in Norway.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
-
Not a phased trial
Phase numbers describe drug development. The registry uses this when they do not apply, as it does for trials of devices, procedures or behaviour changes, and for observational studies.
- Participants
-
About 72 people
The number the study aims to enrol. It can still change while the study runs.
- Expected to start
-
Jan 2026
An estimate. Start dates often move.
- Expected to finish
-
Mar 2027
An estimate. End dates often move.
- Lead sponsor
-
A government agency
The lead sponsor is a government body.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
-
10 years and older
- Sex
-
Anyone
- Healthy volunteers
-
Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
There are two general trial populations. The first population is primary school children in Norway. Primary school children in primary schools meeting the following criteria will be eligible: 1. Schools with more than 10 students in either 5th, 6th, or 7th grade (typically aged 10-13 years). 2. Schools with at least one classroom of sufficient dimensions to accommodate the installation of two portable air purifiers. 3. The school principal accepts the installation of air purifiers in at least one classroom in the 5th, 6th, or 7th grade that meets the first two inclusion criteria. For logistical and administrative reasons, the investigators will try to limit the sampling frame to schools in municipalities located close our offices in Oslo. These municipalities include several large towns with populations of around 30 000 to 100 000 people, as well as sparsely populated rural areas, and are therefore reasonably representative of Norway and many other countries. The investigators will enlarge the sampling frame as necessary. The second population is teachers at primary schools in Norway. Teachers meeting the following criteria will be eligible. 1. Be the main class teacher of one or more of the classrooms included in the trial. 2. Provide informed consent.
Get updates
Get notified about this study
Sign up to get updates when this study changes or when new studies for Asenteeism are added.
Genom att skicka in godkänner du våra Användarvillkor
Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
How to take part
Only the study team decides who joins. These are the ways to reach them.
-
The places running it
1 site. The list below names each one and where it is.
-
The official record
The full official record for this study. This one lists no contact details, but it is the first place any would appear.
-
A doctor treating you
A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.
Contacts and locations
Locations
-
Norwegian Institute of Public Health
Oslo, Oslo, 0213, Norway