Asbestos has been found in at least 1,000 wind turbines across the UK after components imported from China were used in brakes for lifts and hoists.
The white asbestos, chrysotile, has been banned in the UK since 1999.
GMB has written to the UK Government and the Health and Safety Executive seeking details of an ongoing clean-up operation.
Louise Gilmour, secretary of GMB Scotland, told The Sunday Times: “Our country banned asbestos decades ago because it was killing workers and their families, but we now pay for it to be ferried here from the other side of the world and then pay again to remove it?
“We deserve to be told exactly how this happened and what is being be done to prevent it happening again.”
There is no suggestion that lift suppliers or wind farm owners were aware asbestos was present in the components when they were installed.