Nine students at the Higher Learning Institute on Carling have been taken to hospital as a precaution following a classroom mishap this morning.
Marc Messier with Ottawa Fire says students were doing an experiment with chemicals around 11:20 Wednesday morning and mixed the wrong amounts causing chlorine gas.
The teacher immediately evacuated the students and opened the windows.
Paramedics assessed 11 students and ended up taking 9, in between the ages of 10 and 17, to CHEO.
They all had minor throat and eye irritations, even shortness of breath.