More than 200 firefighters at huge factory blaze in Sydney's west

Firefighters are still battling a major blaze that ripped through a disused building in Sydney's west, sending a huge plume of black smoke into the air that could be seen from across the city.

The Mobis Parts Australia building, on Peter Brock Drive in Eastern Creek, was previously damaged in the hail storm on Anzac Day this year and has been in the process of demolition.

Police blocked the road and a NSW Fire and Rescue spokesman said over 120 firefighters were initially dispatched to the scene.

Old car parts and flammable material fuelled the blaze, which forced the evacuation of 90 people.

More than 200 firefighters from 35 stations have surrounded the smouldering fire to ensure it does not flare up again.

Hazmat crews are monitoring the situation due to the danger of chemicals still remaining on the property.

The wind had mostly carried the smoke away from the M4 but traffic slowed to a crawl and significant delays are expected.

The Mobis Parts Australia building, which was a Hyundai supplier, is a 30,000sqm property and suffered at least $2.5m worth of damage during the hail storms on April 25.

A company spokesperson said at the time that they lost most of their car parts in the roof collapse.