Hundreds of workers have walked off Brisbane's Queen's Wharf redevelopment construction site amid asbestos concerns in materials used on-site, the union representing construction workers has said.
It came after the supplier of the fire-rated plasterboard, USG Boral, sent a letter to its customers warning of "very low levels of asbestos contamination" found in the company's Western Sydney plant.
The health warning prompted hundreds of workers to walk off the $3.6 billion redevelopment site as a precaution while testing was undertaken.
But late on Tuesday, the construction company managing the site, Multiplex, said testing had found no traces of asbestos at the Brisbane redevelopment.
The CFMEU said the product was used in indoor areas that required fire-rating, as well as in the staff lunchroom on the Queen's Wharf site.
The union said it was "impossible to know at this stage" how many other sites around the nation might have been drawn to a precautionary stop.
Asbestos found in imported materials
USG Boral said the asbestos contamination was found in vermiculite imported from China in products at its western Sydney plant.
It asked for the product to be "quarantined" as they waited for the results of further testing.
CFMEU national secretary Dave Noonan said this was an example of the risks posed by imported materials.
"Asbestos has been banned from being imported, manufactured or mined in Australia for decades, but in a range of countries, including China, asbestos continues to be used," he said.
Mr Noonan said there was a track record of similar products halting the progress of major infrastructure projects and risking the health of workers.
"It happened at 1 William Street in Brisbane, and it happened at the Children's Hospital in Perth when that site was being constructed — we've seen imported building products containing asbestos coming in from China," he said.
USG Boral said only small amounts of the vermiculite ingredient were used in its products.
In the letter, USG Boral managing director Tony Charnock said it was "likely that this contamination occurred at the source of mining the vermiculite", and "prior to delivery" at their sites.
The company has announced it had "stopped using the Chinese-sourced vermiculite" in the wake of the contamination.
The Queen's Wharf redevelopment is slated to be completed in the first half of 2023.
