Small amounts of R134a

I see that it is possible to buy small 900g cans of R134a on ebay. This is not the hydrocarbon substitute. Is it totally legal to have this or does the regulations only apply to larger quantities? I was reading that the law in the UK was subject to quantities over a certain amount. I ask because I want to try R134a in a tiny system I have using a bd35f dc compressor. I never vent refrigerants and always store and recover them properly.

https://www.gov.uk/guidance/calculat...ty-of-an-f-gas

Or try your local Halfords, they used to sell it for car top upx.

I went and bought the ebay stuff as the car ones probably have other additives. I don't like 134a at all and would rather use hydrocarbon refrigerants but I need to use non flammable stuff for safety reasons as the systems are home made.