If you work under UK Law, see the Health & Safety Executive (HSE) website
for more information and guidance. If you are elsewhere, you need to investigate the appropriate authorities and local laws for this kind of information.
In many legislative areas hazard identification is seen as the first step towards a health and safety policy.
In some cases this could be as simple as walking around your premises and writing down all the hazards you see. Where different departments have different hazards, it may be beneficial to have a designated person within the department who carries out this task.
Once hazards have been identified, employers should then have an effective system for responding to these. Ideally, hazards should be eliminated, however if this is not possible then steps should be taken to minimise both the hazard and it's potential effect.