Four fire engines and around 25 firefighters tackled a fire at a warehouse on Abbeydale Road in Wembley.
Around ten tonnes of carbon materials in an external machine and a small part of the building's external ducting were damaged by the fire. There are no reports of any injuries.
Control Officers took the first of 18 calls at 0117 and mobilised crews from Park Royal, Wembley and Willesden fire stations to the scene. The fire was extinguished by 0340.
The fire is believed to have been accidental.