Is transformer oil flammable and how is fire risk mitigated in substations?

Mineral transformer oil is flammable, with defined flash and fire points. Fire risk is mitigated through containment pits, fire barriers, oil separation systems, nitrogen blanketing, and automatic fire suppression. Fire resistant fluids such as natural esters or silicone oils are used in sensitive locations. Proper cooling, oil level monitoring, and preventive maintenance further reduce ignition risk during faults.