• Investigation into an accident
• If there is a significant change like a new machine or new work process
• Change in personnel or workers personal circumstances (e.g. pregnancy or disability etc)
• Results of workplace inspections
• Information from monitoring incident report forms and absence records
• New information about the hazards
• Changes to legislation
• Increased number of defects or faults reported
• Departmental restructure
• If it is suspected to be no longer valid.