UKCasual

Deaths from asphyxiation related to pepper spray. Are far from unknown. And while odds are other health conditions are involved in most past cases. Those deaths are why it has been banned here.

We are def what the US would call a nanny state. But most are fine with this to the greater extent.

And self defence in the UK stops at the idea of going prepared. UK laws do not allow anything that is intended as a weapon to be carried. So no punching someone in the process of robbing you is fine. Only if you feel at threat of physical harm. If you are a 6ft muscled man and cought an 80yo tiny pick pocket taking your wallet. And punched him. The police would arrest you both. In fact in most situations where you attacked someone robbing you. You should expect to have to show you felt at threat. Not uncommonly in court. Depending on the result of your attack.

Punching someone with a knuckle duster would mean your were preparing for a fight when you decided to take it with you. So illegal. And attacking someone running away after robbing you would be a crime.