Transformer mineral oil is generally classified as a combustible liquid rather than a highly flammable one. It has a relatively high flash point, typically above 140°F (60°C), which means it requires a substantial amount of heat to ignite. While it can catch fire under certain conditions, such as high temperatures or direct contact with an open flame, it is not as easily ignitable as other flammable liquids. Therefore, while transformer mineral oil is not considered highly flammable, it is important to handle it with care to prevent any potential fire hazards in industrial settings.

The inhibitor content in transformer oil refers to the specific additives included to enhance the oil’s performance and longevity by reducing oxidation and preventing the formation of sludge and corrosive acids. These inhibitors are crucial for maintaining transformer efficiency and reliability, as they help protect the insulating properties and overall health of the oil. Typically, the inhibitor content is formulated based on the desired lifespan of the transformer and the operating conditions, with common inhibitors including phenolic compounds, amines, and other antioxidant agents. Regular testing of the inhibitor content in transformer oil is essential to ensure optimal performance and to schedule timely oil regeneration or replacement as needed.