A hazardous materials unit was sent from Hamilton to assist.
Emergency services attending the incident on Anzac Ave in central Auckland. Photo / Jason Dorday
Herald photographs showed firefighters in hazmat gear being sprayed in a portable shower.
Radden said decontamination was precautionary because unknown contaminants may be on the smoke-affected level.
Hato Hone St John said it was notified of the incident at Anzac Ave at 5.15am today. One ambulance, one rapid response unit and one operations manager attended.
Three patients, all in minor condition, were assessed and treated at the scene (no transport required). The crews have since been stood down.
Fire crews left the scene with police at 12.45pm.