Here in the UK, within industry we have to have any electrical equipment within the work enviroment tested to make sure that it is safe to use.

Is the UK the only country that carries out this type of testing or are the other countries who do this.

Within the stage industry, most insurance companies require that electrical/lighting equipment carry a UL or equivalent rating but I don't know of any laws regarding any "temporary" equipment. Everything permanent must be installed to the NEC, NFPA and any other applicable local codes.