The government is advising businesses to use CO2 monitoring equipment to check whether indoor spaces are sufficiently ventilated to stop the spread of Covid-19 in them.
Ahead of a further reopening of the economy next week ministers want offices, shops, pubs, and restaurants to identify poorly-ventilated spaces as part of their risk assessments and take steps to fix them or close them off.
In a change of emphasis, advice which previously stressed social distancing and masks, has been amended so that ventilation is now “the priority” for risk assessments.
The new approach may impose extra costs of some businesses, some of whom have already spent significant sums Covid-proofing their premises in line with the old rules.
But an evolving understanding of the way the virus spreads – predominantly through aerosol – has prompted a change in approach.
“A CO2 monitor could help you assess whether a space is poorly ventilated. If you can’t improve ventilation in poorly ventilated spaces, minimise use of these spaces,” the government’s new advice, published on Wednesday, says.
“People exhale carbon dioxide (CO2) when they breathe out. If there is a build-up of CO2 in an area it can indicate that ventilation needs improving.
“Although CO2 levels are not a direct measure of possible exposure to COVID-19, checking levels using a monitor can help you identify poorly ventilated areas.”
Advice for fixing a poorly-ventilated space includes opening windows, doors, and improving air ducts and mechanical ventilation.
The use of any space found to have poor ventilation that cannot be fixed should be minimised, the guidelines warn – in a move that could see restaurant backrooms and snug bars closed off.
The government says local councils and the Health and Safety Executive (HSE) will enforce the new rules with nationwide checks, and that businesses could be prosecuted for “significant” breaches.
TUC General Secretary Frances O’Grady said the new guidelines were “a recipe for chaos and rising infections”.
“They have been published without proper consultation with unions or employers, just two full working days before restrictions end on Monday,” she said.
“Instead of providing clear and consistent guidance on how to keep staff safe at work, the government is abandoning workers and employers.
“As infection rates surge, every employer must by law carry out a thorough risk assessment and take action to keep their workers safe.
“But these inadequate guidelines will leave many employers with more questions than answers and worried about their liability if they get things wrong.”
On Monday Boris Johnson urged the country to adopt “extreme caution” as the final lockdown restrictions are lifted on 19 July.
The Prime Minister called on companies to stagger their transition back to office work throughout the summer, but is removing the remaining legal restrictions on personal activity.
