A blown safety valve on a refrigeration unit at a Hastings industrial site yesterday appears to have been responsible for releasing ammonia gas on to neighbouring properties and making workers ill.
Occupational Safety and Health and management at Freeze Dried Foods NZ were yesterday investigating.
Between 9.30am and 10am the gas leakedinto the air, making six people ill.
They were taken to Hawke's Bay Hospital with breathing problems, and one had chest pains.
They were in a moderate condition.
Hastings OSH service manager Murray Thomson said an inspector was at the site yesterday afternoon, but had yet to report. OSH learned of the incident through the media yesterday morning.
Freeze Dried Foods NZ general manager Alastair Gass said those affected were working on a neighbouring property.
"It came from a refrigeration system. It looks like a component in the control system failed, a safety valve blew.
"I suppose in that respect the thing worked the way it should. The pressure got up a bit high and it blew, but obviously it put out a bit more ammonia than what we would have wanted."
The refrigeration unit was new this year and it was the first time there had been any major problems with it.
"We've got some experts in ... working out exactly what went wrong and what steps are needed to fix it."
