Hi Joe
R290. or any other refrigerant.
Does not have to come under F gas to be restricted in its use.
Ammonia or Co2 are good examples.
However they and the use of all other refrigerants is regulated under the European Regulation EN 378.
This the bible as far as we are concerned and ignorance of it is no defence.
I SUGGEST NICK SAVES THESE POSTS!
An equipment owner is ultimately liable when and if things go wrong.

I an off to work now Nick.
When I get back I will try and find the relevant passages.

Basically you are totally correct to question the directives / implied instructions you are receiving!

Grizzly