Two workers have been injured at BP's Kwinana Refinery.
A DFES spokesperson said they received a triple-0 call around 9.30am on Tuesday after reports of a machinery malfunction.
"Emergency services and onsite teams have isolated the incident and it is under control. All people on site have been accounted for. Smoke observed in area is dissipating," a tweet from BP Australia read.
A BP spokesperson said the cause of the incident is "unknown" and an "investigation is underway".
A man in his 60s was taken to Fiona Stanley Hospital with smoke inhalation while another man in his 40s was conveyed to Rockingham Hospital with minor burns.
The families of the men have been notified.
BP confirms that an incident occurred at our Kwinana Refinery (WA) at approximately 9am (WST) this morning. Emergency services are on site. More details to come.— BP Australia (@BP_Australia) July 30, 2019
Kwinana Refinery update. Two people are being treated for injuries - families have been notified. More to come.— BP Australia (@BP_Australia) July 30, 2019