Assistant Professor of Virology at Trinity College Dublin Kim Roberts has said hard surfaces, such as lunchboxes, are more likely to transmit Covid-19 than school uniforms.
She said lunchboxes should be washed daily.
Prof Roberts told RTÉ's Today with Sarah McInerney that there is not enough solid evidence about fabrics retaining the virus but when they are washed at 60C the detergent will adequately kill any virus present.
She said if parents cannot manage to wash school uniforms every day they should not worry that they are putting their child or others at increased risk.
She said the virus survives longer on hard surfaces like pencils, pens, lunchboxes and drink bottles so these items will need to be labelled and washed daily.
Prof Roberts said people should expect some outbreaks of the virus in schools when they reopen, but transmission rates should be low overall.
Dr Glynn said he was not aware of this being part of public health advice, but would investigate the claim further.
He said "there is no zero-risk environment" and there will be a proportion of children who are diagnosed with Covid-19 when school resumes, but he said the vast majority will have very mild symptoms at most.
The Health Protection Surveillance Centre has reported that there have been 395 confirmed Covid-19 cases notified in Ireland in children aged 5 to 14 overall up to midnight on 8 August. There have been 2,109 case in the 15 to 24 age group.