Large plumes of black smoke were captured on video by shocked residents near Willoughby Drive in Rainham on Friday morning.
Around 25 firefighters have been tackling the mixed waste blaze after it broke out just before 11am.
Two outhouses were destroyed, a van has been damaged and mixed waste and gas cylinders were involved, the London Fire Brigade told the Standard.
The fire was brought under control just before 1pm and there have been no reports of injuries.
It is not understood to be connected to the on-and-off landfill fires at nearby Launders Lane that have been raging for decades.
Fire trucks remain on site and an investigation into how the fire started is underway.
The thick black smoke alarmed at least one resident, who said it reminded him of the Wennington fire last summer which destroyed several homes.
The village, on the edge of Havering borough in east London, was the scene of a devastating wildfire during the peak of the summer heatwave, on July 19.
James Young wrote on Twitter: “A year on from last years horrific wildfires in East London which burned down part of Wennington Village, we have another...fire in Rainham Essex, only a five-minute drive from Wennington.”
Londoners are being urged to avoid using disposable barbeques this weekend as temperatures are set to climb to 30C in the capital.
The first heat alert of the year has been issued for London between 9am on Friday and 9am on Monday as millions are expected to flock to parks with dry grass.
The London Fire Bridage warned in a tweet: “If you’re heading to the park this weekend to enjoy the weather, please do not take a disposable BBQ with you. They can easily cause grass fires, especially in hot weather when the ground is dry. “
The Met Office has also issued a yellow alert for thunderstorms in London on Saturday from 2pm to 9pm.
