Ventilation
[ch 1: page 25]The new guidance highlights the important role of good ventilation in mitigating the risk of aerosol spread of Covid-19 in enclosed spaces.
“Good ventilation brings fresh or cleaned air into indoor spaces,” it sets out. “The more fresh air that is brought inside, the more diluted any airborne virus will become. In poorly ventilated spaces, residual virus can remain in the air after an infected person has left and increase the risk of Covid-19 spreading.”
It explains how to maximise the supply of fresh air in premises and advises employers to prioritise identifying areas of the workplace that are usually occupied, and poorly ventilated, in their risk assessment. It refers to HSE guidance in this area, including on using carbon dioxide (CO2) monitors (see page 112).
A CO2 concentration of above 1500 parts per million (ppm) in a space indicates poor ventilation, and employers should take action to improve ventilation where CO2 readings are consistently higher than 1500ppm. Where there is continuous talking, for example, it recommends providing ventilation sufficient to keep CO2 levels below 800ppm.
Also see Chapter 6.
HSE, Ventilation and air conditioning during the coronavirus (COVID-19) pandemic (https://www.hse.gov.uk/coronavirus/equipment-and-machinery/air-conditioning-and-ventilation)