Caledon OPP say an unknown chemical discovered in barrels by town employees Thursday posed no risk to public safety.
According to police, town employees found the substance inside 45 gallon drums and transferred the barrels to the towns public work yard, located on Castlederg Sideroad, north of Bolton.
Town employees contacted emergency responders as a precautionary measure to assist in identifying the unknown substance.
Seven homes in the area were evacuated for several hours as a precaution.
Hazmat teams from Brampton were brought in to help contain the scene and investigate.
The Provincial Emergency Operations Centre was also called in for assistance.
Castlederg Sideroad was closed between Highway 50 and Duffy's Lane while emergency crews investigated.
At this point, there is no indication where the unknown chemical came from.
