DONGNAM Petroleum Ind. Co., Ltd. is a leading insulating oil manufacturer based in South Korea, supplying a wide range of high-quality insulating oils for applications from distribution transformers to high-voltage power transformers.

In addition to mineral-based oils, we also produce BIOTRAN-35, a fire-resistant and environmentally friendly natural ester fluid. BIOTRAN-35 is UL Classified and FM Global approved, meeting international standards for safety and performance.
With proven reliability and a strong focus on innovation and sustainability, DONGNAM continues to support global transformer manufacturers with advanced insulating solutions tailored to modern electrical and environmental demands.