Blast injures 7 workers

Two men escaped death when the machine they were doing routine repairs on in Hamilton exploded, injuring them and five colleagues working nearby.

The seven men, all aged between 40 and 52, were taken to Waikato Hospital's emergency department with minor injuries, including mild concussion, cuts and bruises, after the explosion in an industrial print drier shortly before 1pm yesterday.

The incident happened at the Canpac International plant, a Fonterra-owned packaging facility which prepares nutraceutical and baby food formulas for multinational dairy companies.

Smoke from the site was visible a kilometre away.

Hamilton Fire Safety Officer Ross Fleet said investigators trying to establish the cause of the explosion had traced it to the print drier in one part of the large plant, which is in an industrial area about 5km north of the Hamilton central business district.

Mr Fleet said two technicians were doing maintenance repairs on the 40m-long gas-mains-powered machine, which prints sheets of metal before they are turned into cans.

They tried to restart it when it failed, causing a "quite significant explosion".

"It has caused quite a bit of debris damage inside the building," Mr Fleet said.

It is unclear how far the two men were thrown in the explosion or if any of their five colleagues - who were working nearby and inside the plant at the time - suffered injuries from the debris.

A Fonterra spokesman said the company would conduct an internal investigation, and a Department of Labour spokesman said last night that it, too, would investigate as the explosion happened at a workplace.