"It was an unpleasant environment, for the guys to go into the building, but they had all the protective equipment.
"It was a small fire in the loading dock where they have their raw materials.
"At that stage we didn't know what the product was. It wasn't until management arrived did we determine it was sulphur."
Because of the unknown chemicals a "third alarm" was sounded, bringing 12 fire units from throughout the region, "just to get the support we needed in case it got away on us," Mr Nichol said.
"We evacuated the immediate vicinity with police. There weren't many to evacuate simply because it is reasonably rural - there weren't too many people in the area and it being Sunday morning there weren't too many people working."
"Once we knew what chemical it was we were able to decide what extinguishing medium to use and went in with water.
"It went out fairly quickly, which was quite lucky."
Police closed Maraekakaho Rd until 11am. St John's Heretaunga territory manager Brendan Hutchinson said there were no injuries.
Mr Nichol said the evacuation area was small because of the weather. "It was a really still morning so we were quite lucky really. There was no downwind and the fire was fairly well contained in the building.
"So there was a whole lot of stuff in our favour.
"The guys did well - it was a good save."