In the light of the furore following the murder of schoolgirl Sarah Payne, unions are keen to see official clarification that responsibility for identifying paedophiles should lie with the police.
The unions are represented on a working party with government officials that is looking at the issue.
Chris Keates, assistant secretary for policy at the National Association for Schoolmasters and Women Teachers, said: "Emotions are running so high on these issues that what we need to calm everything down and clarify what everyone's role is in this area.
"Campaign groups distribute material on paedophiles thought to be in the area and say to heads: 'If you have this information, why can't it be shared with us?'
"Our concern is that schools should not be the focus for releasing this information. We are recommending that new national guidelines emphasise that the source must rest with the police."
Present guidelins agreed by the police and heads two years ago were reached after an intense debate. They say heads should not tell parents if they know of local paedophiles, and it is up to the police to decide who should be warned and how.
Ms Keates said teachers needed three things from the working party: a consistent, national policy, because some local authorities had an advice system for schools and some did not; a named person in the authority to advise heads; and a clear message to parents that schools did not have not access the sex offenders register and could not pass on information.
She said: "We need people to understand that we are responsible for children in our care, while they are in our care, but not in the wider community. That is a matter for other authorities.
"We don't want people thinking that if the police will not give them information then the school will."
David Hart, general secretary of the National Association of Headteachers said:
"In the wake of the tragic circumstances of the past few weeks, we need to review the situation."