Waste management company Cleanaway has been convicted and fined $650,000 over a chemical fire in Adelaide that injured a worker in July 2013.
Judge Geraldine Davison handed down the penalty in the South Australian District Court on Wednesday following an investigation by federal work, health and safety regulator Comcare.
Cleanaway Operations Pty Ltd pleaded guilty to one charge of failing in its duty to ensure the health and safety of workers under the Commonwealth Work Health and Safety Act.
The fire broke out at the company's Wingfield chemical waste processing plant near Port Adelaide when workers were conducting a production-scale trial to distil a new industrial solvent from a chemical mixture.
Comcare said a loud explosive rush of air was followed by a large flame that burst from a metal still.
A worker standing about five metres away was knocked to the ground by the force of the fire and was treated in hospital for minor injuries.
In sentencing, Judge Davison said workers had very limited information about the new product.
Comcare chief executive Jennifer Taylor said the incident exposed workers to avoidable risks.
"The worker's injuries could have been significantly worse and other staff could have been exposed to the same risk of serious injury," Ms Taylor said in a statement.