A Sydney man has burns to 80 per cent of his body after an explosion at a smash repair workshop in the city's west.
Fire & Rescue NSW Superintendent Paul Johnstone said the "flash fire" broke out at the Dunheved auto workshop, near St Marys, shortly after 3pm on Sunday.
"Most of the fire was already out by the time we arrived, but unfortunately one 40-year-old male has had burns to 80 per cent of his body," Supt Johnstone said.
The injured man was flown via CareFlight helicopter to Sydney's Royal North Shore Hospital, where he arrived in a serious but stable condition.
CareFlight's doctor said the man had suffered burns to his arms, legs and face when fumes ignited at a spray painting booth.