Here in the US Menards carries a 30wt non-detergent oil in their mower oil section. Probably not a big seller, or a non seller actually. Might be good for use in some gear boxes and general lubrication? Oil selections have been argued to death lately, darn near impossible to actually know what oil has what additives, and what motors need certain additives.
What is happening is EPA regulations keep on getting tighter for things that do not matter nor make a difference.
So oil formulations need to keep changing
All of the oils with a primary viscosity of less than 10 were developed to reduce drag on CAR engines so the engine fires on the very first piston that comes up to TDC firing stroke so there are almost no unburned fuel released into the atmosphere.
Unfortunately very low viscosity oils drain almost completely so things have to be added to make them stick to metal bits to avoid a dry start if the engine has not been run for a while.
Lead, Copper and now Zinc have all been added to the EPA's "devils metal" list so have to be reduced or replaced all together.
What generally happens is they get replaced with something 20 times worse for the enviroment but it takes the EPA 10 years to work this out so they eventually ban that and the cycle continues.
Eventually the EPA boffins will catch up with reality and work out the old formulas were best and the enviroment can handle the contaminants provided they are not dumped in massive amounts.
There are bacteria that consume oil, quite a few of them but the dispersants that we put on oil slicks so they don't look bad kill off the bacteria.
This is of course along the lines of "if you can not see it , it does not exist " theory of pollution.
There are also fungi that consume oil which like the bacteria are also killed by the dispersants we use to break up spills & slicks.
The fungi are safe for cattle to eat and then the pollution no longer exists because it has been turned into food.
However solving any pollution problem is not part of the EPA's charter and of course would put them out of business.