Celluloid can spontaneously combust at elevated temperatures. Metallic ytterbium dust can spontaneously combust, and the resulting fumes are hazardous. Rags soaked with tung oil can spontaneously combust (burst into flame). Large manure piles can spontaneously combust during conditions of extreme heat. Another problem is the reluctance of the fuel to vaporise and combust at low temperatures. This is their first engine to combust liquid oxygen and liquid methane propellants. Nitrate film badly stored has been known to spontaneously combust. A combustible material is something that can combust (burn) in air. Battery defects caused many Note 7 units to overheat and combust or explode. Under the right conditions, nitrate film can even spontaneously combust. Swarf may also spontaneously combust, especially if the swarf is coated with cutting oil. Consequently, it will combust, sometimes explosively, with many compounds, such as hydrocarbons. Electrical power can be generated by burning anything which will combust. Oxyhydrogen will combust when brought to its autoignition temperature. During trials, the hands of a girl named Amber spontaneously combust.