Why is transformer vegetable oil considered an eco-friendly alternative?

Vegetable based transformer fluids, usually natural esters, are considered eco friendly because they are readily biodegradable and have lower environmental persistence than mineral oil. They also often have higher fire points, which can reduce fire risk and containment requirements in some settings. Additionally, natural esters can manage moisture differently, potentially supporting insulation life in certain conditions. Tradeoffs include higher purchase cost, different low temperature viscosity behavior depending on formulation, and the need to confirm compatibility and retrofill procedures for existing equipment.