Anecdotally, 230V is safer than 120. 120V will put you into fibrillation, whereas 230V will stop it.
Fires are generally caused by loose connections with higher resistance getting hot and catching something nearby on fire. The British connection in OP is much less likely to have a loose connection.
In my first aid class in a 230V country we were taught: Someone who got an electric shock always needs to visit the emergency room, even if they seem to be fine. Reason: fibrillation has to be ruled out or stopped.
So 230V stops it does not sound right. Whether there is any difference in probability I have no clue.
This is the first time I hear this and I doubt it’s true.
Typically the distinction is made between 50 and 60 Hertz, where 60Hz is typically considered safer(though I’m not sure if this is even true).
I am an electrician hence why I am curious.
I was told by the supervisor of my high voltage lab as part of the "one hand in your pocket" speech. It's also not hard to find similar statements via Google. Neither are definitive sources.
Ok, well it’s wrong. 230V is more dangerous than 110V, all else being equal.
It's not wrong. 110V is more likely to cause fibrillation. Fibrillation isn't the only way AC can kill you so which is more dangerous is more debatable.
The problem is that the risk of death is so low for both that people's perceptions are skewed. Everybody has been shocked by their household voltage a bunch of times, so they think it's no big deal. Until it isn't.