Five people have been transported to Southland Hospital after an explosion and chemical leak at a factory in Edendale, Southland.
A Fonterra spokesman who did not want to be named, confirmed it was at the company's Edendale plant, 40km northeast of Invercargill.
The Fire Service had closed partof the factory and cordoned off the State Highway nearby for about an hour this morning.
The road is now open.
St John Ambulance spokeswoman Alena Lynch said five patients had been transported with minor injuries to Invercargill Hospital.
Edendale deputy chief fire officer Charlie Nicholson said hydrochloric acid was inadvertently mixed with a different chemical which resulted in a chemical reaction.
Mr Nicholson, who works at the Fonterra factory, said the majority of people were evacuated from the immediate area but it is now "back to normal business".
A Fonterra spokesman said the accident happened as the chemicals were being unloaded.
He said those at the scene had been treated for gas inhalation.
The spokesman said there was a chemical reaction which resulted in the release of chlorinate gas.
He said a routine investigation would be launched at the factory.
The Department of Labour confirmed it had been told of the explosion and said it was sending investigators from Dunedin.
