At first he seemed relatively unresponsive and needed to be physically carried but he was eventually able to stand up, at which time he was stripped of his uniform and doused in water.
TV3 reported other firefighters initially appeared to perform CPR on the injured fireman.
The Fire Service was providing support and assistance to the man and his family, Mr Pickard said.
"As is standard in these situations, a review of the firefighting operation will be carried out to look at what happened.
"A separate investigation will also be carried out into the cause of the fire,'' a statement quoted him as saying.
There were chemicals in the fire associated with the fibreglass used by Racetech, but it was unclear whether they had contributed to the blaze, Mr Key said. Late this afternoon he advised residents to stay inside their homes.
Twelve appliances and 50 fire staff attended the blaze at its peak, but it had been reduced to a smoulder by early evening and there was only a small amount of smoke coming from the building.
David Black of Racetech said he became aware of the fire at afternoon tea break.
"We just stopped for smoko then we smelled smoke.
Company product manager Greg Jones said he had no idea how the fire started.
"The alarm went off and we all got out. It's all about getting out as quickly as possible.
"Within a couple of minutes it was all in flames,'' he said.
