THE Lawter International plant at Grannagh, Co Kilkenny will remain closed until the cause of a serious explosion there on Monday evening has been clearly established and adequate safety procedures put in place to avoid a repetition. It was the second such incident in three years.
Two employees are still being treated for burns in University Hospital, Cork.
Mr Fintan O'Keeffe, from Mooncoin, and Mr William Walsh, from Grannagh, are likely to be detained for some days. Two other men were released after treatment in Waterford Regional Hospital.
Mr Pat Goulding, head of the Health and Safety Authority's process industry unit, said its investigation was likely to take some time because of the size and complexity of the US owned plant. It manufactures resin for the printing ink industry.
The Environmental Protection Agency is also involved.
EPA staff arrived at the site, near Waterford city, just an hour after the explosion was first reported.
The fire services were already there and had hosed down the area after one of Lawter's seven reactor "kettles" had exploded, blowing off part of the roof and a wall.
The reactor vessel, which has an estimated capacity of 10,000 litres, was being charged with paraformaldehyde when the incident occurred. It already contained natural gum resin as well as two chemicals, p-tert-butyl phenol and octyl phenol, neither of which is regarded as particularly toxic.
According to a statement from the EPA, some of the contents of the reactor vessel escaped as a black cloud of dust which came to ground in the vicinity of the plant.
This "caused irritation to nearby residents who complained of bad smells, sore throats and bad taste in mouths," it said.
On the agency's instruction, the other six reactor kettles in the plant were shut down.
According to an EPA source, the explosion was probably caused by a "flame arrester" in the ducts linking the damaged vessel with a newly commissioned incinerator, for which it granted a licence last July.
The EPA has asked Lawter for a full report on the accident. This will be assessed, along with the reports of its own inspectors, before any decision to allow the plant to reopen.
A more detailed investigation is being carried out by the Health and Safety Authority, which will have the final say.
Mr Goulding, of the HSA, said it appeared that part of Lawter's environmental control system was implicated in the transmission of a fire which led to the explosion.
The key issue for the HSA is what precisely caused the fire.
"Until we establish that and until the necessary preventive control measures are in place to avoid a recurrence, we won't allow the process or plant involved to restart," Mr Goulding said.
The previous fire in August 1993 caused a dust explosion in another part of the factory. The company was prosecuted at Waterford District Court under health and safety legislation, pleaded guilty to three charges, and was fined a total of £1,500.
The three counts were that it did not take all practical steps to prevent an explosion by excluding possible sources of ignition, that it did not check the effectiveness of protective systems, and did not arrange for any possible explosions at the factory to be vented safely.
Mr Maurice Parker, Lawter's general manager, said the company was co-operating fully with the EPA and the HSA in their investigations. He pointed out that it had been investing in modern equipment at the factory in co-operation with these agencies.
