Young Perth worker injured

A man in his 20s has been rushed to hospital with a badly injured leg after a workplace incident in Perth's rural north.

The man was injured at Limestone Building Block Company in Nowergup about 7.20am on Wednesday.

Department of Mines and Petroleum safety director Andrew Chaplyn said the Finlay Blocking Machine operator had sustained serious cuts to his right leg.

"The injury occurred when the operator accessed the machine while in operation," he said.

The man was initially treated by paramedics from Two Rocks and then a critical care paramedic on the rescue chopper which took him to Royal Perth Hospital for emergency treatment.

The department has started investigating the incident and inspectors are visiting the site.