Teachers are calling for a ban on wireless Internet from British schools amid fears of children being exposed to cancer risk.
It is being claimed that the rush to install wi-fi may have a "significant impact" on young pupils.
The move comes after claims, which have been disputed by officials, that wireless networks give off three times as much radiation as a typical mobile telephone mast.
Official guidance recommends a "precautionary" approach to buildings masts near schools, saying parents must be notified first.
Teachers say the same rules should be extended to wi-fi systems.
But architects suggest wireless networks are likely to become increasingly important for schools.
"I don't know whether wi-fi is safe but there is an accumulation of evidence that suggests it can have a significant impact on growing children, in particular the development of the nervous system," Telegraph quoted Philip Parkin, general secretary of the teaching union Voice, as saying.
Around three-quarters of primary schools and almost all secondaries in England already have wireless technology.
But Parkin insisted that - until research proves it is safe - all further expansion of networks should be halted.
"Our view would be that nobody should move in any significant way until the results of that review are known," he said. "We need to be absolutely sure it is safe. We need more clear and definitive evidence," he said.