Health experts have been brought in to carry out an assessment of the risk to children from the exposure to asbestos at a Derby school.
Pupils from Silverhill Primary School are being taught at four other schools in the city, after the asbestos was discovered earlier this month.
Specialists from the Institute of Occupational Health in Edinburgh have been flown to Derby for two days.
It is thought the clean-up may cost hundreds of thousands of pounds.
Investigation underway
The specialists will collect air samples and assess the health risk posed by asbestos fibres which were released into the air during refurbishment work.
The clean-up operation is well under way and expected to take up to five weeks.
Meanwhile, pupils resumed lessons on Wednesday in four other schools in Mickleover.
A council investigation into the incident is underway.