Incident Description
During a flight, a passenger wearing an Ecoquest Fresh Air Buddy Personal Air Purifier around his neck was observed using a Sprint Trio 700 camera phone near a window. After a noise described as "like a fuse," a flash and loud bang occurred, and smoke emanated from the phone or purifier. The passenger flung the air purifier away because it had started to burn him. The device then exploded into a ball of flames "about the size of a volleyball" and fell between seat cushions, igniting a fire. Other passengers poured water and other liquids on the smoldering cushions, and a flight attendant used a Halon fire extinguisher to extinguish the fire. The battery was never recovered.
Examination and Analysis
The National Transportation Safety Board (NTSB) conducted an examination of the device. A fire and explosion expert reported that the air purifier originally came with a 3.6V CR123A non-rechargeable lithium primary battery. However, a kit containing a charger and a rechargeable lithium-ion battery was available for purchase. The battery compartment cover was found melted and deformed, with two areas of metal splatter. Analysis of this splatter revealed the presence of manganese, a component in primary (non-rechargeable) lithium batteries. The report noted that a short circuit is the most common cause of battery fires, and that charging a non-rechargeable battery could cause an internal short, leading to thermal runaway, battery failure, and possibly an explosion.