It has been revealed that radioactive material was being stored in one of the units at the industrial complex where a fire burned out of control for several hours this afternoon.
RTÉ News understands that the material involved, stored in lead containers, is Iridium 192 and is used in industrial radiography for checking the integrity of pipe networks.
It is understood the company involved has a licence to store the material from the Radiological Protection Institute, a condition of which is that the local fire service is informed.
Fortunately, the unit involved escaped major damage and experts called in detected no increase in radioactivity.
The fire has destroyed the Refond textiles plant and a number of adjoining business units and up to 150 jobs are in the balance.
But several other units, including Northside Community Enterprises, where more than 300 people work, and the Spring Grove laundry company, which employs 100, were saved.
Fire fighters were hampered by poor water pressure for a time, while a gas mains ruptured and exploded into flames and the asbestos roof of the Sunbeam building collapsed.
The fire is now under control but fire fighters are expected to remain at the scene through the night.