"Major hazard installation" within these regulations refers to "an installation where any substance is produced, processed, used, handled or stored in such a form and quantity that it has the potential to cause a major incident", where major incident "means an occurrence of catastrophic proportions, resulting from the use of plant and machinery, or from activities at a workplace."

These regulations are applicable to employers, self-employed persons and users, who have on their premises, either permanently or temporarily an installation or a quantity of a substance which can pose a significant risk of resulting in a major incident, that could affect the health and safety of persons outside the premises. These regulations are in the process of being reviewed.

These regulations require employers to undertake a risk assessment of the major hazard installation. Some of the components which the risk assessment should include are:

These regulations require that an on site emergency plan is compiled and is readily available for implementation at all times.