Is Lubricating Grease Flammable?

Is Lubricating Grease Flammable? In order to be considered flammable, a substance must have a flash point below 100 degrees Fahrenheit, and very rarely would a lubricating grease fall into this category. … This means bearing grease is typically only flammable in the presence of an open flame or sparks. Why is lubricating oil flammable?