2. Identifying poorly ventilated areas

The priority for your risk assessment is to identify areas of your workplace that are usually occupied and are poorly ventilated.

You should prioritise those areas for improvement to reduce the risk of aerosol transmission.

There are some simple ways to identify poorly ventilated areas:

  • Look for areas where people work and there is no mechanical ventilation or natural ventilation such as open windows, doors or vents etc
  • Check that mechanical systems provide outdoor air, temperature control or both. If a system only recirculates air and has no outdoor air supply, the area is likely to be poorly ventilated
  • Identify areas that feel stuffy or smell bad
  • You may wish to use carbon dioxide (CO2) monitors. Checking CO2 levels will help you decide if ventilation is poor. The monitors are less effective in areas used by few peopleĀ 

How an area is ventilated is just one of the factors you are required to consider as part of your risk assessment.

This page is reviewed regularly and updated to reflect any changes in the guidance.

Page last reviewed: 31 March 2021

Next review due: 30 April 2021

Updated 2021-03-31