A PORK pie company had used a potentially dangerous process for 15 years to make its baking tins non-stick before an explosion and fire destroyed its North Yorkshire factory and left it with £2m of uninsured damage, a court heard yesterday.
Vale of Mowbray Ltd had routinely heated paraffin oil with a flashpoint of 175 degrees centigrade in its baking tins to stop pies sticking.
But the oven was operating at 220 degrees when the doors were blown off, starting a fire fuelled by a ruptured gas main, which spread through the building last August.
The company, which pleaded guilty to failing to provide a safe system of work for its employees, was fined 8,000 by magistrates at Richmond and ordered to pay the Health and Safety Executive's investigation and prosecution costs of 23,112.
Alun Williams, prosecuting for the HSE, said five racks of tins were being heated up in the oven on the Industrial Estate at Leeming Bar, near Northallerton, on August 17, when the explosion and fire occurred. The tins contained paraffin oil used to give them a non-stick coating.
An HSE investigation revealed that literature supplied with the oil by Morris Lubricants showed it had a flash point of 175 degrees centigrade.
Mr Williams said 175 degrees was the maximum safe operating temperature, but the oven was being run 55 degrees higher.
Destruction of the oven – serviced six weeks earlier – made it impossible to discover the source of the ignition which caused the explosion, but inquiries showed the company had not carried out a risk assessment to establish whether there was any hazard in using the oil to make its tins non-stick.
"If an assessment had been carried out you would not expose this oil to anything in excess of its flashpoint," said Mr Williams. Data sheets were available and the Health and Safety Executive offering guidance, he said.
Graham Hunsley, on behalf of the company, said it was accepted – with the benefit of the HSE investigation and hindsight – that the system in use had been unsafe.
But it was a process fairly widely used in the baking industry and one that had been employed at the Vale of Mowbray factory for 15 years, he said.
Mr Hunsley said the company had inherited the system from the factory's previous operator – a large national organisation with its own health and safety department. It was understood the previous owner had carried out a risk assessment.
"For many, many years this procedure was used without incident." Mr Hunsley said.
It appeared that the specification for the oil may have changed, he added.
"One of the directors is aware of a data sheet showing a significantly higher flashpoint – something in the region of 400 degrees."
Mr Hunsley said the oven, which cost 80,000, had been used since 1997 and there had been problems resulting in its manufacturer being called out several times to replace insulation and change the computer controls.
Although the oven's manufacturer had recommended annual servicing, Vale of Mowbray had asked the company to service it twice a year.
Tests carried out during the HSE investigation suggested a burner had been misaligned and this may have caused cracks which could have been the source of ignition leading to the explosion.
"That's why, after 15 years, this accident occurred in 2002. If that was the cause, and it seems the most likely, then the misaligned burner is something which has not arisen as a result of anything my client's company did. They feel strongly that it is something the service schedule should have shown up."
Mr Hunsley said the Vale of Mowbray directors believed the company which had made and serviced the oven should bear some responsibility for what had occurred and that was a matter which might result in other proceedings. His clients had been insured but they were still likely to lose around 2m.
He told magistrates: "I hope you will take the view that this is a responsible company which hitherto has been proud of its health and safety record and takes away from this incident the relief that no one was injured and damage was only material or commercial."