A release of the potentially harmful material was discovered on July 12 within a corridor at Bridge of Don Academy where work to improve security is being carried out during the school holidays.

Highlighting previous health and safety concerns raised by union representatives, Unite regional officer Tommy Campbell has asked Aberdeen City Council to hold a full briefing of building services staff by senior management.

He He said: “There is great concern that the workers could be contaminated with a potentially dangerous substance and if the full health and safety procedures relating to suspected asbestos exposure were not followed by management then these workers have left the site and run the risk of contaminating other workers and members of the public.

“Unite representatives have repeatedly made our health and safety concerns known about previous potential asbestos exposure incidents. It beggars belief that we have yet another serious potentially dangerous situation where the management has failed to respond properly in line with health and safety regulations, and their own policies and procedures.

“Unite is demanding that a full and transparent investigation should be carried out by the HSE given the number of serious complaints the union has made over the past year to Aberdeen city council.”

Asbestos materials were disturbed by building service workers during the removal of a panel. However, it took a few working days for the local authority’s own risk control team to be made aware of the suspected asbestos exposure situation. The area involved has now eventually been made safe a week after the incident and the materials removed for further examination.

An Aberdeen City Council spokeswoman said: “The format of the meetings being delivered are on a team-by-team basis to all frontline building services staff.

“Support is in place for those staff directly affected by the incident and any subsequent clean-up operation of the site would be carried out by specialist contractors equipped to deal with asbestos, not council cleaning or janitorial staff. The site was made safe as soon as management were made aware of the potential issue.

“As this forms part of the investigation it would be inappropriate to comment further.”

She added senior council officials had met Unite to discuss the union’s concerns.