Most greases will burn, but they are generally not considered to be fire hazards. Most lubricating greases contain petroleum-derived mineral oil or hydrocarbon-based synthetic fluid as the lubricating fluid. Those materials are generally considered to be combustible (flash point at or above 38 Â°C (100 Â°F). Buy Automotive oils. In very few cases, the lubricating fluid in a grease would be considered to be flammable (flash point below 38 Â°C (100 Â°F). Consult the Safety Data Sheet (SDS) for firefighting information for any specific product.