I bought a universal adapter named 'Grounded world travel adapter' in Hong Kong (attached the image). However, there was a sticker mentioning 'This product is not designed to engage with a main socket in Hong Kong. Don't use the UK plug before leaving Hong Kong.'. (UK plugs are used in HK.)
Since I bought it to use in Hong Kong, I decided just to use it, but I want to ask what would be the possible reason for banning its usage in Hong Kong. Is it unsafe to use? Or any political reason?
Yes, I have such an adapter. It works as well in HK as anywhere else, but has not been tested and/or does not pass the local regulatory laws (nor does it likely pass them in other places, but that's out of their jurisdiction). The HK plug is identical to the UK plug of similar dimensions, as you might expect from their history as a colony of the UK.
They refused to sell it to me at HKIA unless I told them I would not use it in HK. Also had the (easily removed) sticker.
Probably something to do with the (lack of) grounding in some circumstances.
Generally such "adapters" are not approved. In my experience, they run the gamut from "competently designed but technically not approved or approvable" to downright hazardous.
