A massive fire in a south Auckland scrap metal dealer is close to being completely doused.

Fire and Emergency were alerted to the fire at Sim Pacific Metal on James Fletcher Drive in Favona, early on Wednesday morning.

Crews worked throughout the day, with more than 80 firefighters battling the blaze as it burned through 1600 tonnes of scrap metal, some piled up to 12 metres high. Excavators were needed to break up the mounds.

The operations have been scaled down, with five fire trucks and 20 firefighters at the scene on Thursday morning.

Incident controller Chris Power says the fire is now out and crews are working to dampen any hotspots.

They are expected to remain there for the next couple of hours.

It had been hard, dirty work for the crews, Mr Power said.

"Our firefighters have worked extremely hard, many working through the night and the early hours of the morning to get this blaze under control," he says.

Fire investigators have visited the site but the cause of the blaze is yet to be established.
James Fletcher Drive is now open.

People living in the area are encouraged to keep out of the smoke, stay inside and shut all doors and windows - closing down ventilation systems if they can.

Any smoke residue should be wiped down from hard surfaces, including areas where food is prepared, floors and window sills.

Mr Power said there is little smoke coming from the site now, but if people have any health concerns they could contact Healthline on 0800 611 116.