But electricity exists in that bathroom. Zones were the old way of
safety when RCDs did not exist. A human with wet feet could walk a
meter inside that same room and touch something electric - two wire or
three wire. And yet somehow that is considered safe? Zones were once
considered sufficient protection. But today, the RCD for any
electrical light, switch, or outlet anywhere in a bathroom is now
considered necessary. 20th Century code requirements, because the
technology once did not exist, are not sufficient for 21st Century
humans.

The original point posted to the OP. Current technology is now so
cheap and so effective that a best solution for all bathroom circuits
is the RCD. Low cost of that solution is why that solution has been
standard elsewhere for 30 years: all bathrooms electricity provided
only by local RCD circuit. The most 'electrically at risk' human is
one with wet skin. Not just in a bathtub. Wet skin is when natural
electrical protection is severely diminished. Wet humans can be
anywhere in that bathroom. Therefore we routinely install RCD devices
for any electricity in that bathroom.

I am so surprised that some UK residents would only worry about
legalities and not worry about the risk. Any wet human anywhere in
that bathroom is at major risk. Any electricity anywhere in a bathroom
should be via an RCD device as has been standard in NA for the last 30
years. This because an RCD solution is so effective AND because the
protection is so inexpensive.

The original poster jon was asking about electrical safety in the
bathroom. RCDs have long been a basic and most well proven solution
to electrical safety in bathrooms. Exceed code requirements. Install
21st Century safety - the RCD. Safety standards proven and used
standard for decades. Safety standards that still are not standard in
the UK where some insist 20th Century safety codes are sufficient.

Any doubt about that bathroom safety? Install an RCD. So effective.
So inexpensive. Long been available in the UK. Considered necessary
where bathroom electrical safety is taken seriously.

Bob Eager wrote:
On Mon, 13 Mar 2006 07:06:11 UTC, "w_tom" wrote:
If RCDs do not provide human safety to UK bathrooms, they why? Why
is electricity at 230 volts in UK bathrooms not a threat when
electricity in Canada and US at 120 volts has been considered dangerous
since 1970s. Why is UK electricity not dangerous in UK bathrooms -
especially when RCDs are so inexpensive?

Because in nearly all cases, there is no need for them as there is no
accessibility to that electricity. Lighting is governed by rules that
include the type of safety holder that can be used. Electrical outlets
are banned in most zones, except for transformer isolated ones.