Originally Posted by KVS
The general rule, electrical safety-wise, is that any voltage level above the safe level of approx. 36V AC can be, and is to be treated as, potentially lethal for a human being. The number of situations where 110V Vs. 240V will make any true difference is so negligible that it cannot be a determining factor.
Don't forget that it's the Volts that jolt, but the Amps that'll kill you.
A friend and I never paid enough attention to the instructions for physics experiments at school. Long story short, one day he zapped himself with 1100V, at about 0.01 mA (the exact number elude me). Got a nice shock, but not significant after effects.