A man has been rushed to Perth with serious injuries after a caustic spill at Alcoa's Pinjarra refinery.
Department of Mines and Petroleum spokesman Simon Ridge said an Alcoa worker sustained severe burns to his left eye and lower body about 11.40am on Tuesday.
He said the man was airlifted to Perth.
The incident involved an uncontrolled release of caustic solution in the precipitation area.
“Two inspectors from the department’s Resources Safety Division were on site yesterday to commence an investigation,” Mr Ridge said.
“Alcoa reported the incident as required and is also conducting a full internal investigation.”
The man, who has reportedly lost sight in his left eye, was admitted to the burns unit at Royal Perth Hospital on Tuesday.
He remains at RPH in a stable condition.
Caustic soda, or sodium hydroxide, is a chemical compound that reacts strongly when dissolved in water.
The reaction produces copious amounts of heat.
Alcoa uses caustic soda in the first step of its Bayer Processing System to extract alumina from bauxite ore.