Compensation could be sought by members of staff from an Ammanford-based knitwear firm after a cladding site foreman failed to accurately remove asbestos.
Corgi Hosiery and Dragging Cladding have been fined by the Health and Safety Executive (HSE) - which was formed in 1975 - following a thorough investigation into the New Road branch in Carmanthenshire.
Inspectors discovered staff members had removed a sheet made from the dangerous substance from the roof, but had also taken out plaster-like material from the underside of the structure.
They then found the cladding company's foreman Stuart Phillips had instructed two employees to use a hammer and chisel to remove the matter from the building network.
HSE officials claimed visitors to the premises were potentially exposed to asbestos, as the firms failed to restrict access to the main building, while one member of staff was based in the area throughout the operations.
Inspector Anne Marie Orrells said: "Had Mr Phillips adequately assessed the risks prior to the start of the work, it would have been apparent that the work should have been carried out by an asbestos-licensed contractor."