5.19pm: An ammonia leak at a Mount Maunganui coolstore has been stopped and most roads re-opened to traffic.
Fire service area manager for Bay of Plenty coast Murray Binning said firefighters were called to Real Cool Cold Storage Tauranga on Mark Rd about 1.20pm and arrived at the coolstore to find a "significant" leakage of ammonia escaping both into the building and outside of it.
Firefighters immediately created an evacuation zone which stretched about 800m downwind of the building. About eight fire trucks including the hazmat command unit were at the scene, he said.
One coolstore worker had received minor burns from the leak and was treated by St John at the scene but was doing fine, Mr Binning said.
Mr Binning said fire fighters and staff at the coolstore had managed to stop the leak and were in the process of ensuring the building was safe for staff to re-enter.
Firefighters in fully encapsulated suits with breathing apparatus were measuring the gas levels and checking for residue inside the building, he said.
Ammonia gas was used as a refrigerant at the coolstore but could be deadly if inhaled.
"Ammonia gas is a very dangerous gas and it can be lethal and certainly has been lethal in the past. It's a significant hazard when there's a leak," Mr Binning said.
"That's what warranted the enormous evacuation zone.
"It's an asphyxiant in high concentrations and can lead to pretty much instant incapacitation."
All roads in the area except for Triton Ave and Mark Rd had been reopened, he said.
Mr Binning said he expected fire fighters to be done at the building within the hour.
3.01pm: One person has minor injuries after an ammonia leak in Mount Maunganui.
Businesses around Hull Rd, Mark Rd and York St are being evacuated.
EARLIER: A number of residents are being evacuated following a chemical spill in Mount Maunganui.
Police have been called out to Mark Rd, following reports of an ammonia leak at a property there. The leak appears to have originated at Real Cool cold storage on the corner of Mark Rd and York St.
Real Cool manager Mark Batten declined to comment when contacted saying he was busy dealing with the situation.
Authorities are asking people and residents in the area to leave their homes as quickly as possible.
Cordons have been put up in Hull Rd, through to Tukorako Dr and Totara St.
Triton Ave and small streets around the area have also been closed off.
A woman who worked at a business next door said she had smelt a "pungent" chemical smell and staff had called the fire brigade.
Since then they had been evacuated.
Authorities say the chemical spill will take several hours to clean up.
"We ask that people please follow the instructions of police in the area and evacuate immediately.''
Police said they were first advised of the leak about 1.20pm.