What standards must a transformer oil manufacturer meet?

Manufacturers typically need to meet relevant oil quality standards such as IEC 60296 for unused mineral insulating oils and associated IEC test methods. They also must comply with quality management and testing requirements demanded by utilities and industrial buyers, including batch certification, traceability, and safety documentation such as SDS. Depending on market, additional compliance may include ASTM product standards, REACH or similar chemical regulations, and environmental requirements for non PCB status. Buyers often require third party testing or audits to qualify suppliers.