nonwithstanding residual current breakers or not. That device would not be legal over here.
The American OSHA (Occupational Safety and Health Administration) has a broadside I've seen that says, in short, that a grounded cord and plug doesn't protect you, but a GFCI (residual current breaker, as they call them over there) will.
Why?
Electricity doesn't take the path of least resistance; it takes
all available paths. If I grab a hot wire that's connected to a lamp, even though there's a connection through the lamp's bulb that has lower resistance than the dry skin of my hand, some (tiny) fraction of the current will still pass through my body -- and with American 60Hz AC, if as little as 30 mA of that current runs across my chest, it may induce ventricular fibrillation. If it does so, and there's no one nearby who notices me collapse
and either knows CPR or has and knows how to operate a defibrillator, I'll die. On the spot. In less time than it takes for paramedics to arrive.
On the other hand, if the lamp cord is protected by a residual current breaker or GFCI, the device will trip and shut off the voltage to the wire I've grabbed, at one third the potentially lethal level of current (10 mA is low enough most people can't even feel it), and in less than 1/60 of a second (much too fast for the current to induce ion flow that can reduce the skin resistance). In other words, a GFCI will save me where a ground wire won't. What a ground wire does is ensure that a misconnection from hot wire to conductive frame will blow the overcurrent breaker for the circuit -- which might prevent a fire, but won't save the guy who's got part of that current running from one hand to the other (common circuit breakers take anywhere up to ten current cycles to trip on a big overload, much longer if they're barely over their rated limit; slow-blow will run as much as twenty times that long -- and that's long enough to kick the heart out of rhythm, at least part of the time).
Then there's the whole issue of miswired outlets -- I'm not even an electrician, but I've seen a good number of outlets in American homes that had egregious errors like ground tied to neutral, ground just not connected, ground tied to a water pipe (which used to run into the ground, but now connects to a plastic replacement pipe, so isn't actually grounded).
A device with a metal frame
should be grounded (because popping the GFCI whenever you connect the mains plug is a clue there's a problem), and that device probably couldn't be sold without a ground today, but
any electrical device, grounded or not, used in an environment like a kitchen, bathroom, or darkroom ought to be plugged into a GFCI circuit. I'd be confident using a device like this one on a GFCI circuit with that two-wire cord, even in a location where I might have one hand on the device frame and the other in grounded standing water or touching a cold water pipe (in a house old enough to still have metal plumbing) -- but if I had such a setup, I'd certainly test the GFCI frequently.
