Pupils are being used as guinea pigs until research establishes whether there are any risks from the use of wi-fi in schools, teachers warn.
The association is concerned the full facts are not known
The Professional Association of Teachers, at its annual conference, is seeking an inquiry into safety concerns surrounding new wireless technology.
The association is also concerned about the levels of asbestos in schools.
The government said its expert advice was that there was no problem with wi-fi and no reason to discourage its
Speaking at the conference, in Harrogate, PAT general secretary, Philip Parkin, said the issue of wi-fi systems prompted heated debate, with some scientists expressing concern and others convinced of its safety.
The former Education Secretary, Alan Johnson, has previously pointed to advice from the Health Protection Agency, which says there is no risk from wi-fi.
Mr Parkin said: "There is a view out there that you have no right to express concerns on such issues and that if you do, you are scaremongering or promoting so-called bad science."
But he said that because some scientists were concerned about the risks, an inquiry was necessary.
"I have heard and read enough to make me concerned and I had been made aware of an accumulation of evidence which suggests that the non-thermal, pulsing effects of electromagnetic radiation could have a damaging effect upon the developing nervous systems of children.
"The frequently-quoted current safety limits in operation refer to the thermal effects of such radiation and not the non-thermal effects.
"My real concern is that until there is a full inquiry based on both existing evidence and on newly-commissioned research work, the nation's children are being treated as guinea pigs in a large-scale experiment."
Mr Parkin also called for more guidance for schools over asbestos.
"Our serious concern about the asbestos issue is the lack of information and basic level knowledge available to schools and governing bodies," he said.
"There has been no national assessment of the extent of the asbestos problem in schools and so, at a national level, it is impossible for government to allocate resources in proportion to the risk."
Mr Parkin said the risks from asbestos in schools was unknown and that this was "entirely unsatisfactory".
Schools Minister Kevin Brennan said: "The welfare and safety of children and staff in school is absolutely paramount - which is why we have already addressed concerns covering wireless computer networks and asbestos.
"The Health Protection Agency has consistently advised that they do not consider there to be a problem with the safety of wifi."
It was widely used in homes, offices and in public areas.
On the basis of current evidence and expert safety advice, government computer agency Becta believes there was no need to discourage its use.
"We have also put in place clear guidance for schools and local authorities to help them identify and manage any risks posed by asbestos."