The importance of managing asbestos at premises has been highlighted by the Health and Safety Executive (HSE).
Earlier this year, Canadian company Vale Inco Europe Ltd pleased guilty to four charges under the Control of Asbestos Regulation 2006.
The company employed a contractor to work on a furnace at a premises in Clydach, Wales, but the interior of the plant and equipment had not been surveyed for risk of the material.
Andrew Knowles, principal inspector at HSE, said: "Knowledge that asbestos insulation was present would have resulted in a licensed contractor being used to remove the material and prevented these workers coming into contact with asbestos at all."
The dangerous material is the biggest single cause of work-related deaths in Britain, with 20 people a week dying from diseases associated with it.
Ms Knowles also highlighted that there had been no asbestos awareness training for employees "which is a specific requirement where asbestos may be present".