An asbestos scare has stopped work on Perth's new children's hospital and put more heat on the project's contractor.
A worker discovered a white powder in a panel while installing a ceiling fan that looked like hazardous white asbestos, or chrysotile, which can cause cancer and is banned in Australia.
WA Health Minister John Day said an initial test indicated asbestos was present and if that was confirmed on Thursday 150 roofing panels would be replaced.
The Construction, Forestry, Mining and Energy Union said its own independent tests had found asbestos was present.
The hospital's head contractor John Holland sourced the product through Chinese company YUANDA.
As well as being made in China, it was tested there, and found to be asbestos-free during accredited testing in 2013, Mr Day said.
The CFMEU criticised John Holland while the state Labor opposition blamed the government for awarding them the tender, amid widespread complaints over tens of millions of dollars in alleged late and non-payments owed to the subcontractors building it.
Mr Day defended John Holland, saying he thought it had acted appropriately in ensuring proper materials that met Australian standards were being used but said the possible presence of asbestos was unacceptable.
"I would agree that it's not good enough if asbestos is being used in any building projects private or public in WA or Australian in 2016 ... it is very disappointing if that is the case.
"It will be the responsibility of the suppliers and builders to replace the panels if asbestos is confirmed to be present. I don't expect there to be any cost to West Australian taxpayers."
Treasurer Mike Nahan has previously said he was not happy with John Holland over process problems plaguing the hospital.
Opposition health spokesman Roger Cook said it was "gobsmacking" that the government would allow a major public project, such as a children's hospital, being built in 2016 to involve the use of asbestos and questioned whether future repairs and maintenance would further expose people.
CFMEU WA secretary Mick Buchan said the appointment of the John Holland Group to build such an important project for the state was an unmitigated disaster.
"We allege that Holland's have gone for a cheaper product to cut costs and in doing so have put the health and welfare of workers at risk, let alone future occupants of the hospital," he said.
John Holland has been contacted for comment.
