One person was taken to hospital in a serious condition after a chemical incident at the Levin Aquatic Centre today.
A total of 32 people were assessed by ambulance staff after the incident forced the public pool to be evacuated.
Five fire engines and police were at the scene.
A Fire and Emergency spokesperson said chemicals mixed together in a pool and started fuming.
He said everyone was now out of the building and in the fresh air.
They were unable to confirm what the chemicals were.
A Hazmat team is on its way from Palmerston North.
FENZ crews are setting up to investigate the cause of the chemical reaction.
Emergency crews were called at 11.50 am.