John Boyle, the general-secretary of the Irish National Teachers Organisation (INTO), told Newstalk Breakfast the environment has not been easy.
"What the listeners probably don't realise is that there has been really, really a difficult beginning to the school year,” he said.
"And it has been marred actually - it should have been a safe, confident re-opening - but system failure by the HSE, and the lack of support then that went for schools.
"And even the Department of Education - they failed even to convince people not to send symptomatic people into school.
"The department failed to let people know about the new symptoms of the Delta variant, and they promised they would do a public awareness campaign."
Mr Boyle added that before any changes occur around close contacts of a confirmed case more data is needed.
"We know from the HSE that there were way more children and way more schools with Covid-19 in the first two weeks of the school year, than there had been more or less in the whole year last year.
"There was a report issued yesterday, and the report is only a small sample - because of the system failures, they could only give us about 10% of the data.
"So in that regard, until we see that there is data and evidence to support this recommendation by NPHET - and by the way, NPHET haven't said that it's going to happen.
"I would suggest that we will certainly meet every week, and if we get proper reports on the data - and if it's indicating that the trend is downward... but we must remember that we have the largest primary classes in Europe, we have no children wearing masks, we've no children vaccinated.
"So it's not an easy environment at all.
"And the failure of the department even to provide the CO2 monitors in time: all those things mean that the school communities are not confident about the re-opening this year.”
Mr Boyle was speaking as plans being considered by NPHET will see children who are close contacts of a confirmed case of Covid-19 being allowed attend school from the end of September.