Three people have been taken to hospital after being exposed to an unknown chemical at an Australia Post package sorting facility in Sydney's north.
One worker suffered burns to his hands after a liquid spilled from a three-kilogram satchel at the package sorting facility in Frenchs Forest just after 8am on Monday.
A Fire and Rescue NSW spokesman said firefighters, including a hazmat unit, responded to a triple-0 call to the Rodborough Road facility where three people had been exposed to the liquid.
One Australia Post worker had removed the satchel from the building to prevent other workers being exposed. That person is then believed to have taken himself to Manly Hospital for treatment of burns to his hands.
He had been isolated in Manly Hospital until the liquid chemical was identified, and Fire and Rescue NSW spokesman said.
A NSW Ambulance spokesman said two other people who were exposed to the liquid were treated by paramedics and taken to the Royal North Shore Hospital.
Twenty people have been evacuated from the package sorting facility while the liquid is cleared and identified.
Australia Post has been contacted for comment. It was unclear whether the liquid had been posted through the mail.