When setting up your Health and Safety Committee, you can choose to include all employees from the beginning or make the initial arrangements yourself. As consultation is about talking and listening to each other, ideally you should agree arrangements with your employees from the start. It involves them early so gives them a say in how the committee should run.
If you have union-appointed representatives, the union will have written to you to let you know who they are and they may have requested that you set up a committee.
If you do not have union-appointed representatives, or they are not representing everyone, then you will have to arrange elections for your employees so they can choose their representatives. If you want to involve your employees from the beginning of the process, then you can set up a small joint working group to get the committee started. They can help you with arrangements for organising the election.
A working group may only need to meet a few times to get the early arrangements sorted out. The size should be manageable for the aims you want to achieve, usually between 6-8 members but it will depend on your business. It should include at least one, perhaps two senior managers committed to the process of setting up a health and safety committee. They should also be able to speak authoritatively on behalf of the business.
Other members should either be interested volunteers or employees with the right skills or knowledge to help you. The working group can discuss and agree the election process with you. Once you know who your representatives are, then you can start to consult with them about how the Health and Safety Committee will work in practice.