Four people have been taken to hospital after inhaling unknown fumes at a Tauranga recycling plant.
St John Tauranga operations team manager Ross Clarke said the Transpacific AllBrite Industries staff members were taken to hospital as precautions.
"They were conscious and displaying minor symptoms such as dizziness and sore eyes.''
A fire service spokesperson said it appeared a staff member had opened a bottle he thought was water.
The minute he opened the bottle fumes had 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.