Alcoa's chief medic will visit its Kwinana refinery next week to assure workers of its asbestos management procedures - following an incident last month when seven contractors were potentially exposed to the deadly fibres.

The aluminium producer also hit out at what it claims is misinformation from construction unions over the incident where white asbestos was discovered in insulation tape covering weld seams inside a tank roof.

The Kwinana desalination plant in the foreground with Alcoa Refinery at the rear Credit:Tony Ashby

Dr Michael Donoghue, who will brief workers next week, said the risk of any worker developing an asbestos-related disease following brief exposure was extremely low.

"And the risk to people more distant from the task and, particularly, to any family or friends is even lower," the doctor said.