The cause of a commercial-based acid spill in Judea which kept firefighters and the Hazmat unit busy last night is yet to be determined.

Tauranga Fire Brigade was called to the commercial site on Cypress Street, Judea about 8pm after receiving calls from concerned owners of the acid spill within the building.

The Hazmat unit was called to a commercial acid spill in Judea last night.

Senior station officer Mark Keller says four fire trucks were supported by three crews, three pumps and the hazmat unit.

'We were there for about two hours from 8-10pm. We were working on neutralising the acid and then cleaning the acid out and then cleaning up afterwards.

'It was less than five litres I would think.”

The building was already evacuated when fire crews arrived, but the cause of the spill is yet to be determined, says Mark.

'We are a little unclear at this stage as to how the spill came about but we will be speaking with the owner on this matter.”

Earlier in the evening Tauranga and Mount Maunganui crews responded to a private smoke alarm at the old ANZ building on Grey Street.

Mount Maunganui senior station officer Lindsay Nicol says the two crews responded about 5.45pm after a smoking wash light set off the alarm just inside the rear door of the building.

'It was smoking quite a lot and had set off a smoke detector. We isolated the power and removed the light,” says Lindsay.