A building in Timaru and the land it sits on will be tested for contamination after the removal of 133,000 litres of toxic chemicals.
A vat of acid caught fire at Concours Electroplating in February 2015, causing the evacuation of hundreds of people and a massive cleanup.
In June last year, the owner agreed to close the business down to allow Environment Canterbury Regional Council to remove the chemicals, most of which were not labelled.
Council scientist Davina McNickel said the removal of the chemicals had resolved the risk of gas, but the building still posed a hazard to the public.
"Now we're at the point where the building has been cleared but it still needs to be assessed as to whether or not any of the chemicals have actually affected the building fabric - so the wood, the bricks - and that will help us decide the future of the building."
The council said the chemicals had been removed from the building at a cost of $870,000, paid by the government's Contaminated Sites Remediation Fund.