One person is in a stable condition in Middlemore Hospital following a fire at a large Auckland factory producing pre-painted steel products.
Three people were taken to Middlemore hospital with burns as a result of the blaze but the other two have been discharged.
The Fire Service says the fire broke out on Wednesday afternoon at Pacific CoilCoaters - a subsidiary of Fletcher Building - in Great South Road Mt Wellington
Seven appliances attended and brought the fire under control.
Firefighters were washed down to remove any dangerous chemicals.
The Fire Service says it is not clear how the fire started.