An explosion at Incitec Pivot’s Mount Isa acid plant yesterday sparked concerns about a smoke plume.
The explosion happened just after 5.00pm local time on Tuesday.
Police enforced a 100-metre exclusion zone around the site last night.
Mt Isa mine which is located alongside the acid plant was also evacuated as a precaution, an Xstrata spokeswoman said.
The explosion was the result of a chemical reaction which sent a plume of smoke into the air, company spokeswoman Sandi Harwood said.
"Basically there was a chemical reaction in a water treatment cooling area," she said.
"It's a routine procedure but there was a chemical reaction which created a plume. Our people did the right thing and called emergency services – police and fire were on the scene.
"There were no injuries and no loss of production."
Police have since given residents the all-clear to go outdoors following the air quality tests conducted by Queensland Fire and Rescue Service, ABC reported.
Fertiliser and explosives manufacturer Incitec Pivot reopened the sulphuric acid plantearlier last year after it was forced to shut down the operation for maintenance.