Plant operations are back to normal at a Napier Fertiliser plant, where yesterday a sulphur fire injured two firefighters, forced roads to close and residents to evacuate.
Yesterday, central fire service communications shift manager Mike Wanoa said they received a call at about 2.18pm from Ravensdown in Awatoto, advising them a building had caught fire.
Fire crews went to a "fifth alarm" and had 60 firefighters and 12 appliances fighting the blaze during its peak.
About 7.20pm yesterday the site was handed back from the Fire Service, and today all staff have returned to work and normal site operations have resumed.
"The isolated building where the fire occurred has no visual damage and will be assessed for any minor damage today, with a thorough examination to ensure it is safe for staff to enter," Ravensdown CEO Greg Campbell said.
The air in the building had been tested regularly overnight with readings indicating the air is back to normal with no detectable sulphur dioxide found. Personal would not be entering the building until the structure had been accessed and formally signed off.
"I'd like to acknowledge and thank the emergency services for their efforts in containing the fire and ensuring all personal were safe and damage to buildings was restricted," Mr Campbell said.
"They also took control of the situation in communicating with the local community and ensuring their safety. Also our staff, who followed our emergency procedures, which we practice regularly."
The sulphuric acid plant continued to operate through the incident, but superphosphate manufacture ceased for the night shift and was now available again for production. There would be no impact of fertiliser supplies from the plant.
"A thorough investigation as to what occurred will commence today, and any actions required implemented," Mr Campbell said, "I would like to apologise to those affected in the Napier community."