Road closed after gas cylinder ruptured

A man was trapped in his car with suspected broken ribs and a gas cylinder ruptured following a two-vehicle collision in Sydney's west.

A 48-year-old man was trapped for a short time when his car and a van collided at Bringelly just before 9pm on Thursday, causing the van to roll.

He was taken to Liverpool Hospital in a stable condition, with possible fractured ribs, while the other driver, a 28-year-old man, was not injured and breath tested negative, police said.

The van, which was carrying gas cylinders, was being lifted upright when a cylinder ruptured, causing an emergency exclusion zone to be set up.

Northern Road, Greendale Road and Bringelly Roads were closed for about four hours before emergency crews removed the cylinders from the scene.