English schools are preparing for the new term by installing air quality monitors that will test whether classrooms are potential breeding grounds for Covid-19.
Ministers hope the £25 million ($34m) plan will prevent further disruption to schools after months of remote teaching during the pandemic.
Set to be introduced in every state school, carbon dioxide monitors will check whether air breathed out by children is being ventilated out of the classroom.
A high CO2 reading suggests poor ventilation. Health experts say good ventilation can sweep away airborne virus particles and reduce transmission.
Unions and opposition parties say ministers have been slow to improve ventilation after it became clear that this would make schools safer.
The first batch of CO2 monitors will be sent to special schools that have a high proportion of vulnerable pupils.
The rest will be delivered during the new school year in England, which begins in early September. About 300,000 monitors will be installed in total.
A separate trial to take place at 30 schools in Bradford, West Yorkshire, will assess whether air purifiers can reduce the infection risk in classrooms.
UK Education Secretary Gavin Williamson said the scheme was aimed at avoiding further disruption to schooling.
“By keeping up simple measures such as ventilation and testing, young people can now enjoy more freedom at school and college,” he said.
Pupils and staff will be expected to take two tests a week in the new term. The UK’s vaccination programme was recently expanded to 16 and 17-year-olds.
Ministers say that keeping schools open in the autumn is a priority after two prolonged periods of closures in 2020 and early 2021.
Schools are no longer expected to keep children in segregated “bubbles”, although the government says these may return if necessary. Face coverings are no longer advised in classrooms.
“We are all enjoying the return to a more normal way of life and getting our children back into school is a really important part of that process,” said Health Secretary Sajid Javid.
“We want to ensure schools are both safe and comfortable for students and staff – and have been clear that good ventilation is crucial.”
Teaching unions say that ministers have been slow to address ventilation and have expressed concern over the end of bubbles and face coverings.
Kevin Courtney, a joint general secretary of the National Education Union, said he hoped the CO2 monitors showed that ventilation was being taken seriously.
“Sadly, Gavin Williamson failed to get on the front foot over the summer but the initial investment of £25m in CO2 monitors is welcome now and will start to make a difference,” he said.
“Ventilation is essential, but it cannot be the only measure in place, especially if children are not vaccinated.”
The devolved governments in Scotland, Wales and Northern Ireland have their own education policies.