How is transformer oil classified in terms of hazard?

Hazard classification depends on the oil type and additives. Modern non PCB mineral and ester oils are usually not classified as highly toxic, but they can be combustible, irritating, and environmentally harmful if spilled. Silicone fluids are often chosen for fire safety. Legacy PCB contaminated oils are hazardous and tightly regulated. Always rely on the specific SDS for transport classification, PPE requirements, spill response, and disposal rules.