Ideally all staff should receive the practical training, but this is not always possible - however as a minimum they should all undertake training in the emergency plan and basic fire prevention, which should ideally be recorded.
I only asked the type of business as certain occupations may involve higher fire risks making the practical training of all staff more vital.
Dont forget you can get to see how an extinguisher works for real, albeit not on fires when your own extinguishers require test discharging for extended servicing or overhaul.
There are links to the draft Regulatory Reform (Fire Safety) Order on this site - however if you are already complying with the current law, having a fire risk assessment, suitable and sufficient precautions, etc, then you will be most of the way to complying with the new order as it will be centred around a risk based regieme