An emergency in Mataura which involved potentially poisonous ouvea premix has ended, with Fire and Emergency New Zealand crews finding no sign of a toxic gas leak.
FENZ was called to the Mataura facility just after midday on Sunday, after reports of a sprinkler activation.
A hazmat unit from Invercargill was called in to help Mataura firefighters, as the premix - a by-product of production at New Zealand Aluminium Smelters' Tiwai Point facility - can create a toxic ammonia gas cloud when mixed with water.
A FENZ spokeswoman said the sprinkler appeared to have broken due to frost, and crews found ‘‘four inches’’ (10cm) of water on the floor of the building.
However, they did not find any toxic gas, and the scene was now taken over by the building owner, the spokeswoman said.
State Highway 93 between Clinton and Mataura, as well as several local roads, were closed as FENZ investigated the scene.