Six fire engines and around 40 firefighters attended a chemical incident at a soft drink production facility on Roding Road in East Ham.
Crews were called to a strong smell of chemicals. 80 people left the area before the Brigade's arrival and were assessed on scene by London Ambulance Service crews.
Firefighters set up a 100-metre hazard zone and carried out a monitoring sweep and found no elevated readings of chemical substances.
The Brigade was called at 2318 and the incident was over for firefighters at 0255. Firefighters from East Ham, Plaistow, Dowgate and surrounding fire stations attended the scene.