Fire crews have been sent to building on Biak St in Rotorua after a "chemical reaction" was reported.
A Fire and Emergency spokeswoman said "some sort of chemical reaction" meant three fire trucks were sent to the scene in Mangakakahi about 1.18pm.
"At this stage, they are just trying to ascertain what has happened," she said.
While the building itself was evacuated, the spokeswoman said there was no need for a wider evacuation of the area.
