Two fire engines and 10 firefighters and officers were called to a fire at a beauty salon in Chingford after a pile of towels caught fire inside a tumble dryer.
Staff at a private gym in Larkswood Leisure Park, which houses the salon, arrived at work on June 30 and discovered an alarm sounding and smelt smoke.
The building was evacuated and the Brigade was called.
Firefighters forced entry into the salon and found it smoke logged with a smouldering fire in the drum of a tumble dryer.
Crews quickly extinguished the blaze, but the salon and parts of the neighbouring gym suffered smoke damage.
It is believed towels, which had been used in the salon, had become contaminated with oils and began self heating when placed in the tumble dryer.
A fire investigation found the towels had been left in the dryer overnight and had been through one full drying cycle and half a second one.
Charlie Pugsley, from the Brigade’s fire investigation team, said: “Sometimes when materials are cleaned, put in tumble dryers and then either left inside or taken out, folded and stacked, the residual oils in the towels can self heat”.
“This can result in the temperature building up to a point where the material smoulders and eventually ignites.”
The Brigade was called at 0552 and the fire was under control 0629. Fire crews from Chingford and Woodford fire stations attended the scene.