The minute he opened the bottle fumes have come out and the liquid was spread through a lot of rubbish, he said.
Fire fighters have yet to find the bottle or determine what the chemical was.
Earlier:
One person is being treated by emergency service staff after being overcome by fumes released in a chemical spill.
Fire and ambulance staff were called to Transpacific AllBrite Industries on Truman Lane, Te Maunga at 3.20pm.
Fire northern communications shift manager Nicole Bernard said five appliances were in attendance.
"We're responding to a chemical spill. One patient has been overcome with fumes. We're administering first aid and investigation what sort of chemical it is."