The men, who are employed by a firm of industrial cleaners, were working in the bitumen and paint shed at Mungal Foundry when the fire broke out.
‘‘It was like standing beside a tank of burning fat with sparks and flecks of bitumen flying everywhere,’’ said William Middleton, one of the workers.
The men ran to the main building where they raised the alarm.
Mr Middleton, who lives in Fauldhouse, West Lothian, described the situation: ‘‘We had been out of the building and were returning to the bay where we were cleaning out bitumen when fumes burst around us. They were only a few feet away as they exploded showering bitumen everywhere.
‘‘We just turned and ran for out lives.’’
Seconds later the building went up in flames.
Employees at Mungal, which is owned by Carron Company, were on holiday while the maintenance work was carried out. An investigation is now under way.