A Fire and Emergency New Zealand (FENZ) spokesman said fire crews were called to the factory in Auckland’s Takanini shortly after 2pm on Saturday.
“Two staff were affected by a spillage of caustic soda.
“Both of them received moderate injuries and the spillage has now been contained,” he said.
A St John spokeswoman said two vehicles had attended and one patient was transported to Middlemore Hospital in south Auckland.
WorkSafe have been notified of the incident and are making inquiries.