The union representing workers at Waypoint Centre in Penetanguishine want metal detectors.
OPSEU Local 329 thinks the measure would improve worker safety and possibly save lives.
President Pete Sheehan says right now patients have access to items that can be used as weapons against staff.
Earlier this year a patient took a screwdriver from the workshop and used it to stab a worker.
The union is in the midst of a safety awareness campaign.