Oh Yes!!!A Senior moment,but what I meant to add was the French Air Force have experimented with a Vegetable Based Oil that does not have the Carthegens in it,and have obtained reasonable results for Engine Life.These chemicals ,particularly in MobilJet 2,have the capacity to prolong engine life.In BAe years ago on the HS125,we used MobilJet2 to try to prolong the Solar APU which used to have a life of 2/3rds of 5/8ths FA,but failed and the Garret APU was then used and lasted a much longer time,as a result of which MobilJet 2 was used for both the Vipers(Total Loss Oil System) and the Garret 731,with minimal affect on Pax and Cabin.However the more modern Engines seem to churn out a far greater amount of Carsonagenic fumes from Organophosphates.I have not seen any comments with actual Airlines trying a vegetable based engine oil,so maybe no one else except the Fench have done so??