Since 1974 three changes of reporting regulations have occurred and the legislation has catered for reporting of injuries as a result of work activity across employees, self-employed persons and members of the public. The sources of safety statistics for the years 1974 to present are as follows:

• Calendar years (January to December) 1974 to 1980; reports made under various pieces of legislation, but chiefly the 1961 Factories Act.
• Calendar years (January to December) 1981 to 1985; reports made under the Notification of Accidents and Dangerous Occurrences Regulations (NADOR).
• Planning years (April to March) 1986/87 to 1995/96; reports made under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1985 (RIDDOR 85).
• Planning years (April to March) 1996/97 to present; reports made under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1995 (RIDDOR 95).
• RIDDOR 95 also replaced the Railways (Notice of Accidents) Order 1986, and certain provisions of the Offshore Installations (Inspectors and Casualties) Regulations 1973 and the Submarine Pipelines (Inspectors etc) Regulations 1977. Certain provisions of the Regulation of Railways Act 1871 and the Transport and Works Act 1992 were also repealed or amended.

Injury statistics for 1996/97 onwards cannot be compared with those for previous years due to the introduction of RIDDOR 95. Under these revised reporting requirements:

• The term ‘accident’ includes acts of violence at work, and acts of suicide or trespass on railways or other transport system.
• The list of reportable major injuries includes a wider range of fractures and amputations as well as certain dislocations.
• In most circumstances, the criterion for reporting a non-fatal injury to a member of the public is if the person is taken from the site of the accident to a hospital - rather than if their injury is on the list of reportable major injuries.