Face masks in school communal areas, where social distancing cannot be maintained, will be recommended for pupils over the age of 11 in Wales, the Welsh Government has said.
The new guidance also covers pupils travelling on school transport, as well as college students and staff, but does not recommend their use in classrooms.
Schools, colleges and local authorities will be required to carry out risk assessments of their sites to determine if people are unable to keep to the two-metre rule.
The announcement follows talks between government ministers, scientific advisers, local authorities, teaching unions, and the Children’s Commissioner, and comes just six days before schools reopen on September 1.
A joint statement by health minister Vaughan Gething and education minister Kirsty Williams confirmed the news just minutes after the end of the Welsh Parliament’s plenary session on Wednesday.
The statement said: “The current advice from the chief medical officer for Wales is that face coverings are recommended for all members of the public over 11 years in indoor settings in which social distancing cannot be maintained, including schools and school transport.
“We will amend our operational guidance for schools and FE to require settings and local authorities to undertake risk assessments of their estates to determine if face coverings should be recommended for their staff and young people in communal areas.
“This will also include school and college transport.
“As part of the risk assessment we recommend that staff, students, families and unions are engaged.
“Social distancing is still required in the classroom, so face-to-face teaching without coverings can continue.
“The overall interests of the young person must be given priority in these assessments and there must be no risk of exclusion from transport to school.
“Face coverings may need to be provided to young people who don’t have them, if they are recommended locally.”
The Welsh Conservative’s shadow health minister, Andrew RT Davies, later said it was “unacceptable” the announcement was not delivered during Wednesday’s plenary, having earlier told Mr Gething ministers should be able to scrutinise the eventual decision.
Laura Doel, director of the National Association for Head Teachers (NAHT) Cymru, criticised the Welsh Government’s announcement.
She said: “It is unacceptable that school leaders are expected to shoulder the responsibility of deciding if face coverings are required in schools.
“Headteachers are not medical experts and the Welsh Government should not put them in this position.”
She added: “If the Government leaves this decision-making to individual schools or local authorities, we will once again see a mixed economy across Wales, with different schools having different measures in place which will be unsettling and potentially unsafe for pupils, parents and staff alike.
“This will portray a message of confusion, not confidence in returning to school.”
But David Evans, Wales Secretary of the National Education Union (NEU) Cymru, said the message from the Welsh Government was “clear”.
He said: “We welcome the steps the Welsh Government are now taking, having had a chance to review the science. To us the statement is clear – in areas where social distancing can’t be maintained, face masks need to be worn by everyone over 11 years, including in schools and on school transport.
“The Welsh Government needs to give detailed guidance about this, and we will be writing to heads to make sure they are aware of the requirements.”
Earlier on Wednesday, Public Health Wales said another person had died having tested positive for coronavirus, bringing its total number of deaths since the beginning of the pandemic to 1,594.
The number of cases of Covid-19 in Wales increased by 34, bringing the revised confirmed total to 17,808.