What PCB levels are allowed in transformer oil by regulations?

PCB thresholds vary by country and regulation. In the United States, PCB regulatory definitions and requirements commonly use 50 ppm as a key threshold for classifying PCB contamination categories in electrical equipment oils. In parts of Europe, frameworks for inventory and phase out reference 0.005% (50 mg/kg) levels and volume criteria for equipment tracking and disposal. Because compliance is jurisdiction specific, utilities must follow the local legal definitions and reporting rules.