An eye-wash is either a little cup (about 30mL) in which
water or
saline is poured, or a device much like a
water fountain, with a pair of spouts that
sluiced water onto the surface of the eye.
For any worksite in British Columbia that handles hazardous chemicals, the Workers' Compensation Board requires there be some sort of eye-wash present. I doubt that this eye-wash solution would include any tear gas.