Youngsters started to return to classes across the North on Monday for the first time since the coronavirus lockdown started in March.
Some parents have expressed concerns while teachers’ unions say educators had not been given enough time to respond to rules issued earlier this month.
Justin McCamphill, NASUWT national official in Northern Ireland, said: “The fact that 77% of teachers told us they don’t feel their school is safe for pupils to return is very concerning.
“Teachers and school leaders have worked hard to prepare their schools for young people to return, yet 61% of teachers have not been consulted on risk assessments undertaken in their school or college.
“Ministers and school employers must do more to reassure the school workforce, parents and pupils that everything possible is being done to minimise viral spread, and that robust procedures are in place should any outbreaks occur.”
Northern Ireland’s chief medical officer Dr Michael McBride has insisted it is safe to return.
Strict social distancing between children may be relaxed if there are hygiene measures in place.
However three schools did not reopen following the detection of Covid-19 cases.
Ballyclare Secondary School is set to reopen on Tuesday following a deep clean and 72-hour incubation period.
St Kevin’s Primary School and St Louise’s College, both on the Falls Road in west Belfast, have also delayed their reopening following positive cases among the school community.
Some parents have taken to social media to express concern at their children returning to school.
Trevor, a father of five from Co Down, said he is worried as his wife had been shielding during the pandemic.
“As a family, for us coronavirus is a life or death situation,” he said.
His wife has been taking immunosuppressants and is labelled as vulnerable.
Trevor said the number of new daily cases was rising sharply.
He tweeted: “I agree the risk to children themselves is low but that is being used as spin from politicians & school leaders to hide behind the fact that children are ‘spreaders’.
“The issue is not that of children dying but of whom they will pass the virus too and the long-term consequences.”
Other parents have welcomed the return to school.
Maeve Kennedy’s 11-year-old son Jonnie returned to Olderfleet Primary School in Larne.
She said he was looking forward to being reunited with his friends but added his grandmother has been shielding with a lung condition.
She told the PA news agency: “He’s looking forward to getting back and into some sort of semblance of a routine, it’s been a long six months without that.
“I think he needed to get back. I have tried to combine remote working and home schooling with his younger brother going into P6, so the last six months have been really difficult at home.”
She said because of the pressure of going into P7 and around the transfer tests, he has worked very hard, but the pressures have been a real challenge.
Education minister Peter Weir said: “Very, very few, if any, children will come to harm as a result of attending school, but there is evidence of the long-term harm to children’s education, life opportunities, mental health and wellbeing from not attending school.”
Pupils in Primary 7, Year 12, Year 14 – whose preparation for exams was disrupted by the lockdown – and all vulnerable children were due to return to classes on Monday.
All other pupils will begin the new school year on the week beginning August 31 after months of variable levels of home schooling.
A total of £42 million has been spent on re-starting schools safely.
Separately, another 10 cases of Covid-19 have been reported across Northern Ireland in the past 24 hours, the Department of Health said.
