Around 50 firefighters are tackling a major blaze in which 160,000 litres of cooking oil and 30,000 litres of diesel are alight.
The fire started at around 5.15am at a storage yard in Little Warley Hall Lane, Little Warley.
Some 15 fire appliances, including two from Brentwood, one from Ingatestone and one from Ongar, plus four from the London Fire Brigade are on the scene.
As well as the cooking oil and the diesel, 30,000 tonnes of paper caught alight.
The fire service has called in utility firm officials and the Environment Agency.
Once the flames have been extinguished, a joint police and fire service investigation will be carried out to establish the cause of the blaze.
The fire started at around 5.15am at a storage yard in Little Warley Hall Lane, Little Warley.
Some 15 fire appliances, including two from Brentwood, one from Ingatestone and one from Ongar, plus four from the London Fire Brigade are on the scene.
As well as the cooking oil and the diesel, 30,000 tonnes of paper caught alight.
The fire service has called in utility firm officials and the Environment Agency.
Once the flames have been extinguished, a joint police and fire service investigation will be carried out to establish the cause of the blaze.