A science demonstration gone wrong sent one teacher and three students from Royal Crown Academic School on Bayview Avenue to hospital on Thursday.
The class had 17 people present. A drain-cleaning substance was put into an empty plastic bottle, which was spun around. The bottle ruptured and splashed two female and one male student, and the teacher.
The injured are being treated for minor injuries at North York General Hospital.
Toronto fire arrived in hazardous materials gear, but have since left.
CORRECTION: This article originally stated the incident took place at Royal Crown College. It was in fact Royal Crown Academic School, a different institution at the same address.