The Health and Safety (HSE) has published new guidance around ventilation during the Covid-19 pandemic. This guidance applies across Great Britain and is referenced by the Health and Safety Executive Northern Ireland.

In summary, the HSE guidance underlines the importance of ventilation and states:

  • Adequate ventilation does not mean that workplaces have to be cold.
  • Employers should identify poorly ventilated areas, including through the use of carbon dioxide (CO2) detectors.
  • Poorly ventilated areas must be dealt with.
  • Windows may not need to be opened as wide in winter as summer due to higher winds etc., but they must not be closed. Airing rooms can also help.
  • Fan heaters can be used provided ventilation is good, but not where ventilation is poor.

The guidance also gives further information around mechanical systems, such as fans and air conditioning systems. Further advice is also available from the Chartered Institute of Building Services Engineers (CIBSE).

CO2 is exhaled by humans and is therefore a good indicator of ventilation in most circumstances. It is different to carbon monoxide (CO) which is a highly toxic by-product of the incomplete combustion of fuels. A carbon monoxide detector will not give any indication of ventilation.

In addition to the HSE, the SAGE group has also recommended the use of CO2 detectors which can be purchased cheaply from a number of suppliers, with models available for less than £35. A CO2 concentration of below 800 parts per million (PPM) should be aimed for, with values above 1500ppm indicative of poor ventilation with a higher risk of aerosol transmission of the virus. SAGE also reports that 800ppm may not be sufficient for activities which have a potential for high aerosol generation, such as singing and aerobic exercise and these should be avoided indoors.

Although a CO2 detector is not required in every room, the NASUWT strongly recommends, in line with HSE/SAGE advice, that all schools purchase some detectors.

Health and Safety Regulations already state that all workplaces must be adequately ventilated and the HSE guidance emphasises this in terms of Covid-19 and the potential for airborne transmission in workplaces that are not well ventilated.

If they have not already done so, all employers should urgently make an assessment of the ventilation in all rooms in order to identify poorly ventilated rooms. Many workplaces have installed carbon dioxide sensors to minimise the potential for disputes over whether ventilation is sufficient.

Members should avoid working in rooms that are poorly ventilated. Poorly ventilated rooms will often have:

  • No mechanical ventilation and no or limited natural ventilation.
  • Mechanical systems that do not provide outdoor air (i.e. only recirculate air).
  • A feeling of stuffiness or bad odours.
  • If members have concerns around the ventilation in their school, they should raise this with their line manager, drawing their attention to the HSE/CIBSE guidance and request a CO2 detector is provided.

If you are unhappy with the response from their school, you should contact the NASUWT for further advice.