Formal testing is getting underway to determine if RAAC - the lightweight concrete prone to collapse - is in Jersey's General Hospital.
The Infrastructure Minister has faced an urgent question in the States after announcing late on Friday that the material is suspected in four areas.
Deputy Tom Binet said a detailed review of hospital plans had revealed it is believed to be in Block F, housing the pathology department.
He said it is 'possibly present' in two other areas - a disused kitchen which is now a storage and plant room.
Reinforced Autoclaved Aerated Concrete (RAAC) is yet to be confirmed, and all areas of the hospital continue to be used as normal.
Formal testing is starting this afternoon ( 3 October) by qualified structural engineers.
"Work has been underway over the past few days to plan various measures that would or will be implemented in the event that RAAC is formally identified.
Investigations continue and there is the possibility that further incidences may come to light."
Repeatedly asked about the possibility of closing parts of the building, the Minister stressed that would be a judgement for others to make.
He told the States those decisions aren't in the Infrastructure department's remit, but lie with Hospital Maintenance within the Health Department.
"I think it is safe to assume that if the people that look after the hospital maintenance consider it to be sufficiently safe to leave open to the public, then my guess, sir, would be that it would be.
At the risk of repeating myself for the fourth time, it is not a decision that rests with me, and as such I am not able to take that decision."
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