Firefighters have contained a factory blaze at O'Connor-based Western Meat Packers, with the damage bill estimated at $10 million.
FESA said about 45 firefighters will remain on-site for the next few hours until the blaze is completely extinguished.
Concerns were raised earlier in the day that pollution from the blaze may contain toxic fumes, however the Department of Environment and Conservation Pollution Response Unit found there were no toxic particles in the air.
However, FESA is still recommending that people who work in the industrial area between Stock Road, Peel Road, Garling Street and Keegan Street avoid the area.
FESA added the fire has gutted the building and has caused an estimated $10 million worth of damage.
"Two staff were affected by the smoke and taken to a private health care clinic nearby.," FESA said.
About 140 people work at the factory. FESA and the Police Arson squad will investigate the cause of the fire.
