Ottawa paramedics were called to OC Transpo's Bayview station Friday night after reports of a man found unconscious due to a mysterious hazardous substance.
Paramedics say calls came in before 11 p.m.
The HazMat team from Ottawa Fire was dispatched to the scene to determine the type of substance.
Police say the substance allegedly only affected the one man. The patient was taken to hospital by paramedics.
No one else is at risk.
Bayview station is now reopen.
