How should old transformer oil be handled and disposed of safely?

Old transformer oil should be handled as regulated waste until tested and classified. Key steps include sampling for PCBs if legacy equipment is possible, maintaining labeled sealed containers, preventing spills with secondary containment, and using licensed transporters and approved recyclers or disposal facilities. Filters and sludge are also managed as controlled waste. If the oil is PCB contaminated, stricter rules apply for storage, documentation, and disposal. Even non PCB oil should not be dumped or burned, and personnel should follow PPE and SDS guidance for exposure control.