A controlled detonation has taken place at a chemical scene in south Dunedin.
The Defence Force disposed of the volatile hydrazine monohydrate shortly before 10am on Friday.
A Fire and Emergency New Zealand spokesperson told Newshub crews will clean up the scene over the next two hours
A 100-metre cordon zone was set up around the biotech firm Blis Technologies after the discovery of the chemical last night.
Fire and Emergency NZ Senior Station Officer Rob Torrance told the Otago Daily Times (ODT) a small volume of the chemical had crystalised on the lip of its container, meaning it was unstable if it was to be moved.
The plan for the explosion was for an EOD specialist wearing a bomb disposal suit to gingerly carry the chemical outside, place sandbags around the container and detonate it, Torrance told the ODT.
Some properties were evacuated when the chemical was found to have become unstable on Thursday night, but the remaining addresses within the 100m cordon were evacuated on Friday morning.