Take not my name in vain. Richard it would be a good idea to get a qualified electrician to fit a Residual Current Device(R C D) or Earth Leakage Unit Wonderful bits of kit that make the system totally safe. Get the P A T tester who does the office to test the Toaster when it is finished ,that way it does not cost very much. You can always re-imburse the practice
Good Luck with the project