I’ve done a little bit of research and I can’t find any source that has the voltage breakdown of plain vegetable oil.

Maybe I missed something somewhere but I could use some help on this. Or a different point of view.

  • 1
    \$\begingroup\$ Maybe you should start with a specific vegetable oil? \$\endgroup\$
    – Eugene Sh.
    Jan 22, 2019 at 19:07
  • 5
    \$\begingroup\$ Organic sustainably farmed, or regular? \$\endgroup\$
    – John D
    Jan 22, 2019 at 19:14
  • \$\begingroup\$ Regular vegetable oil \$\endgroup\$ Jan 22, 2019 at 19:22
  • \$\begingroup\$ Try Dielectric Properties of Vegetable Oils. Early find on google. Look at Figure 6. \$\endgroup\$
    – jonk
    Jan 22, 2019 at 19:30
  • 2
    \$\begingroup\$ @ScientistSmithYT What vegetable? There are many kinds of vegetable oil -- olive oil, corn oil, peanut oil, canola oil, coconut oil, sunflower oil, flaxseed oil… \$\endgroup\$
    – user39382
    Jan 22, 2019 at 19:39

4 Answers 4


In the US cooking oil that is marketed as vegetable oil is typically soy bean oil. It's breakdown voltage is around 39kV according to https://citeseerx.ist.psu.edu/viewdoc/download?doi=

Canola oil is another common cooking oil in the US it has a similar breakdown voltage to mineral oil, 30kV according to https://aip.scitation.org/doi/abs/10.1063/1.5022926 pdf: https://aip.scitation.org/doi/pdf/10.1063/1.5022926

The article references Rapeseed oil this is another name for Canola oil.


There's actually an extensive research done on vegetable oil, especially on breakdown voltage. The commonly used term to refer vegetable oil in the field of transformer liquid insulation is "natural ester". Japan has used palm oil in some of their transformers since year 2000s. In a paper I read, the breakdown voltage of palm oil (olein) is between 44-60 kV (reference: "Suitability of Palm Based Oil as Dielectric Insulating Fluid in Transformers" by Azis, Norhafiz; Jasni, Jasronita; Ab Kadir, Mohd Zainal Abidin ;Mohtar, Mohd Nazim).

  • \$\begingroup\$ Is that voltage per mm or per meter? \$\endgroup\$ Feb 13, 2020 at 7:03

It probably doesn't exist, there aren't too many people that would be interested in using vegetable oil for an insulator.

This doesn't seem like a hard experiment to preform, put some electrodes in a tank with vegetable oil in it. Get a high voltage supply and keep turning the voltage up until you see a spark: Like this

enter image description here

Source: https://studyelectrical.com/2014/06/transformer-oil-tests-and-purification.html


The type and composition of the oil as well as the temperature of the oil will all effect when the oil becomes conductive. You might have better luck looking for that information regarding mineral oil.

@laptop2d stated "there aren't too many people that would be interested in using vegetable oil for an insulator."

That may be true however there are a number of people interested in using various types of oils as thermal conductor while being an electrical insulator at the same time. I've seen people do this for cooling PC's when trying to do extreme overclocking or just as a novelty, Id imagine there are some niche industrial applications. Here is an example of PC cooling with mineral oil https://www.pugetsystems.com/submerged.php


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