A leak of hazardous gases at Mobil's Altona fuel refinery has been contained.
Metropolitan Fire Brigade (MFB) crews were called to the facility in Melbourne's west just before 2.30am on Friday, after a hydrocarbon leak was detected from a pipe.
The pipe was taken offline and hoselines were used to protect the leak site from ignition sources.
"Maintenance crews are repairing the problem at the moment, but the leak has been contained," an MFB spokesman told AAP on Friday morning.
The pipe was expected to be returned to operation from mid-morning.