Why is the flash point of transformer mineral oil important for fire safety?

Flash point indicates the temperature at which oil vapors can ignite in air, so it is a key parameter for assessing fire risk under abnormal heating or external fire exposure. A higher flash point provides more margin against ignition, influencing substation fire mitigation design, separation distances, and containment strategies. While transformers operate far below flash point, faults can create hot spots and arcing that generate flammable gases. Knowing flash point helps engineers evaluate overall fire hazard, choose fluid type, and comply with safety and insurance requirements.