Sydney mechanic suffers serious burns after gas bottle explodes at workshop

A man has been rushed to hospital with serious injuries after an explosion at a mechanics business in Sydney's west.

The 42-year-old employee was left with burns to his face and body and injuries to his hands and legs after the explosion ripped through the Turbo Exhaust Centre workshop in Smithfield last night.

After paramedics spent 90 minutes stabilising the man, he was taken to Liverpool Hospital, where he remains in a serious condition.

In addition to the serious burns, the man is understood to have suffered multiple fractures to his arms and legs and lost fingers on one of his hands. 

It is believed the man was working with an acetylene gas bottle when it exploded. 

Emergency crews could be seen cooling the exploded cylinder in water. 

A distraught work colleague was at the scene and has spoken to police.

Police have established a crime scene as they continue their investigations, with the matter also reported to WorkCover.