Pop wrote:

240/50 vs 120/60 - they both kill in very nearly the same length
of time. The heart succumbs at about 46V ac.

Both can, and sometimes do, kill, but the vast majority of people who
manage to connect themselves across either survive the experience.
I've had 240V about ten times, and 415 once, and I'm very much still
here. The last 'mishap' I had was about twenty years ago, and was
caused by a horrible Bakelite fitting which I hadn't noticed was
cracked, and which fell apart in my hands. Most of the others were the
result of taking things apart as a small child, and not taking care,
exposing live contacts.

From a safety point of view, using a lower Voltage, but one still high
enough to possibly kill, is no substitute for using good quality
fittings, and taking reasonable care.

Something I have noticed in the US is that many of the fittings in use,
and still available to buy, are of very poor quality, and would never
be allowed here in the UK. The situation here was pretty similar here
maybe 40 years ago, but things have improved a lot since then. There
are a number of things that I don't like about the design NEMA
connectors, I think that both the British and European ones are better,
though none are perfect (try leaving a British plug on the floor and
stepping on the pins with bare feet (ouch!)), but the quality of many
(by no means all) of the NEMA fittings is a bigger issue than the basic
design of the standard. Also, high-quality NEMA plugs seem to be
rather expensive, at least here. A Hubble 240V 6-15P recently cost me
about 12 pounds (~ $20). Given that most things here are about twice
the price that they are in the US, does that mean that they would be
about $10 over there? I bought this to replace the plug supplied with
a 120V-240V autotransformer (to fit the output), which was just about
the worst plug that I have ever seen.