[p886]

Seed oils that are now widespread as cooking oils were originally used as machine lubricants.

[hammock]

Yes my point. They still are.

Soybean oil is used in a wide range of lubricant and functional fluids applications:

  Gear oils and lubes
  Chainsaw bar oil
  Compressor oil
  Two-cycle engine oil
  Metalworking oils and
  Wire rope, chain, and cable lubricants
  General purpose and penetrating lubricants
  Transformer and transmission line cooling fluids
  Greases - automotive, machinery, rail curve, track
  Food-grade, industrial, and elevator hydraulic fluids

https://www.stle.org/images/pdf/STLE_ORG/AM2019%20Presentati...

Obviously this is a backwards example (food-grade oil used for non-food applications), and my question was using this plastic oil for food applications.

[TSiege]

Fascinating and makes sense. I've recently gone down a rabbit hole on the uses of linseed oil pre fossil fuels, but it's too gummy to ever be used as a lubricant. Do you know off hand which seed oils were used for lubricants?

[ElevenLathe]

Castor oil was famously used as a lubricant in early WWI-era airplane engines. The fumes would blow in the pilot's face and are also a laxative.

[trompetenaccoun]

So was olive oil, in addition to the use in food.