If you are organising a public firework display to celebrate Guy Fawkes Night this year, the Health and Safety Executive (HSE) has useful guidance on planning the event, depending on its size and the type of fireworks to be used.
Choosing the right site for the event is crucial. The venue should be large enough for the safe display of the type of fireworks being used and for the bonfire, if you are having one. There are basic checks that you will need to make, for example inspecting the site in daylight to see if there are overhead power lines or other obstructions. It is also important to take into account the possible impact of smoke etc. on the surrounding area given the unpredictability of the prevailing wind on the night.
If you are using fireworks in categories 1, 2 and 3, there is no reason why you should not light them yourself. However, category 4 fireworks may only be used by professional firework display operators.
If you are employing a professional team, you will not normally need public liability insurance as this will be taken care of by the company putting on the firework display. If you are organising a public event yourself, it is advisable to have insurance, although it is not required by health and safety law. Some clubs and associations may have cover under an existing policy, so it is worth checking up on this. It is sensible to shop around to find a provider that is used to insuring such events and will offer cover for a reasonable premium.
The HSE guidance includes a check list of what needs to be done prior to the event, what you should do on the day itself and also on the morning after. It can be found here.