Are electrical ratings the same as in the states...
Not at all. Anything designed for US voltages will need to have a converter as the more than double voltage would likely do some nastiness to any electrics.
Attempt to recall old engineering course details will follow:
For those not aware, the US is rated at 110V and Europe is rated at 230V, but with tolerances that allow the UK to be unchanged from the older 240V which most power supplies will be.
As an example: a US unit designed to work on 110W would need a 1 Amp current (Power = VxA). To get this it would have an equivalent circuit resistance of 110 Ohms (R=V/A).
In the UK the circuit would still have the same equivalent resistance of 110 Ohms, but the current (C=V/A) would now be 240/110=2.18A giving power flowing through the circuit of 523W This gives a current more than double that which the unit is designed to run with and has a high chance of causing damage to the electrics.
Now obviously the figures above are somewhat large for many pieces of equipment we use, but the principle remains the same.
Going from the UK (or Europe) to the US is less of an issue for damage, but the units will get less power than they were designed to have, which is why many UK hairdryers are a bit weak when used in the US.