The Capital District Health Authority is conducting a complete audit of its mattresses after mould was discovered in some hospital beds at the Halifax Infirmary a few weeks ago.
Workers found the problem when they were changing the plastic mattress covers.
The health authority says no patients were at risk.
"Any of those mattresses that were identified were immediately changed. They have now been removed and destroyed and every mattress within the Halifax Infirmary now has a new waterproof cover and has a new mattress so there is no danger whatsoever to patients," said spokeswoman Mary Jane Webber.
Capital Health will now examine more than 1,000 mattresses.
Webber said they hope to have the results in the next few days.