Nearby buildings have been evacuated and the fire department's hazardous materials team is on the scene of a fire at Aerospace Metal Finishing on Proctor Road this morning.
There is concern regarding toxic chemicals used in the plant, according to York Regional Police.
Businesses beside and north of the plant have been evacuated as a precaution.
"No other concerns currently," police posted on social media.
The OPP have closed Hwy. 9 from Leonard to Main Street, in Schomberg, and York police are closing the northbound lanes of Hwy. 27 at Lloydtown Aurora Road.
Proctor and Dilane are also closed.
You are advised to avoid the area and find alternate routes.
