Ventilation during the coronavirus (COVID-19) pandemic

Latest advice on keeping workplaces safe from COVID-19

This page is up to date with working safely guidance in England. You can check the most up to date measures on GOV.UK. There are different regulations and guidance for Scotland, Wales and Northern Ireland.

The latest advice on continuing to keep workplaces safe will help you assess the risks and reduce COVID-19 transmission. This includes links to advice from public health bodies and other government departments on measures not implemented by HSE.

2. Assessing the risk of poor ventilation

As part of your risk assessment to protect your workers and others from coronavirus (COVID-19), you should identify poorly ventilated work areas.

It may help to list areas in your workplace or use floor plans to record how they are ventilated. Remember to include changing rooms and areas used for breaks, such as canteens.

Numbers of people using or occupying an area

The more people who use or occupy an area, the greater the risk of aerosol transmission. The risk increases if an area is poorly ventilated and occupied by more than one person.

Consider how many people use or occupy a space at any one time. Is there a set number of people each day?

Larger work areas

The larger the area, the lower the risk. This is because larger spaces:

  • have more air to help dilute the virus
  • tend to be designed with ventilation rates in mind
  • take longer for aerosols to build up in them

Activities that make people breathe deeper

Activities that make you breathe deeper, such as physical exertion or shouting, will increase the generation of aerosol and therefore increase the risk of transmission, even where there’s adequate ventilation.

Reduce the risk where you can, for example by moving some activities outside.

Features of the workplace that may affect ventilation

Large machinery, equipment or other features (such as pillars) could prevent air circulating. Consider how to improve airflow in the area.

Desk or ceiling fans

You should not use desk or ceiling fans in poorly ventilated areas.

Local exhaust ventilation

You may use local exhaust ventilation (LEV) to control risks from other workplace hazards such as dust or welding fumes. If an LEV system discharges the air outside, it will improve ventilation in the area.

Complex ventilation systems

If your workplace has a complex ventilation system, due to having multiple floors etc, there is guidance from the Chartered Institution of Building Services Engineers (CIBSE).

You may need a ventilation engineer to provide expert advice on the best system for your workplace.

Talk with your workers about your risk assessment

Talking with your workers about the outcome of the risk assessment will help them understand how they can play their part in reducing the spread of COVID-19.

Find out more

The British Occupational Hygiene Society has worked in collaboration with the Health and Safety Executive to develop a freely available tool for assessing general ventilation and COVID-19 transmission.

The tool supports employers, building users and building owners by using a simple scoring system to indicate the effect their ventilation arrangements are likely to have on reducing COVID-19 transmission. It also provides recommendations for taking action, where appropriate.

We review and update this page regularly to reflect changes in guidance.

Page last reviewed: 19 January 2022

Next review due: 30 January 2022

Updated 2021-12-29