Indoor ventilation at home and work: reducing respiratory risk

Better ventilation reduces the build-up of shared indoor air. Practical steps for homes, workplaces, shops and classrooms.

Why indoor air matters

COVID-19 and other respiratory viruses can spread through particles released into shared air. Risk tends to rise in crowded, enclosed and poorly ventilated places, especially during longer contact.

Start with outdoor air

Open windows or doors when practical. Openings on opposite sides of a room can create cross-ventilation. If that is not possible, short repeated periods of fresh air are still useful.

Air conditioning and filtration

Air conditioning that recirculates indoor air does not always provide fresh air. Reduce occupancy and meeting time in closed rooms, and consider an appropriately sized HEPA air cleaner as an added layer.

Plan activities well

Choose better-ventilated or outdoor spaces, encourage people with symptoms to stay away, and use a well-fitting mask when crowded indoor spaces cannot be avoided.

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This content is general information, not a diagnosis or individual medical advice. Seek urgent help for severe or rapidly worsening symptoms.