The Department for Education is working with scientists from the Scientific Advisory Group for Emergencies (SAGE) and NHS England on a pilot to measure air quality in classrooms.
The move comes amid significant pressure on the government to look more closely at ventilation in schools to prevent airborne transmission of the coronavirus.
According to new guidance for schools on how to deal with Covid published today, the DfE is working on "a pilot project to measure [carbon dioxide] levels in classrooms and exploring options to help improve ventilation in settings where needed".
While schools have been told to keep classrooms "well ventilated", many heads and teachers have pointed out that windows cannot always be opened, and that few schools have effective air filtration systems.
Covid safety: Guidance on keeping school classrooms well ventilated
But the importance of ventilation as a Covid safety measure has been emphasised by health experts.
In March, scientists writing in the BMJ commented that "increasingly the evidence suggests that airborne spread is the dominant mode of transmission even at close range" and that additional measures are required to "minimise air-sharing", such as "universal, well-fitted and higher grade masking, particularly indoors; adequate ventilation and air filtration; reducing crowding and time spent indoors; and managing patterns of air flow".
The scientists warned that classrooms were "a high-risk environment", and ventilation "should align with expert guidance".
Then, in April, Fiona Godlee, the BMJ's editor-in-chief, said that there needed to be "major investment" in making schools "safe", adding that an increased emphasis on aerosol spread – meaning transmission through airborne particles – had come "too late" for teachers infected with Covid through a "lack of adequate PPE [personal protective equipment]".