This unit involves the skills and knowledge required to classify areas where flammable gas or vapour hazards may arise. It includes: applying area classification recommendations from relevant codes and standards to meet objectives; gathering and analysing data relative to potential explosion hazards, including characteristics of the hazardous materials; identifying and characterising sources of release; assessing dispersion and ventilation factors; considering plant process and environmental conditions; and determining the extent of a potential release and documenting findings.

Area classification should be carried out by those who understand the relevance and significance of properties of flammable materials (gas & vapours), and those who are familiar with the process and the equipment (refer AS/NZS60079.10.2).

It applies to personnel involved in the front-end engineering and design (FEED) scopes for facilities that may contain flammable gas or vapour hazards, as well as those persons involved in the ongoing operations, maintaining and/or modification of these same facilities, during the facility life cycle. It is appropriate for people who need to meet their responsibilities as required by AS/NZS3000:2018.

Site-specific work permits may be required to work in a classified hazardous area. In addition, other permits may be required, such as confined space and to operate specific pieces of equipment such as elevated work platforms in various jurisdictions. The classification process assists in the implementation of these safe systems of work.

Additional and/or other conditions may apply in some jurisdictions subject to regulations related to electrical work. Practice in the workplace and during training is also subject to work health and safety (WHS)/occupational health and safety (OHS) regulations.

This unit of competency and associated assessment requirements have been adopted from clause 2.15 of AS/NZS 4761.1:2018 Competencies for working with electrical equipment for hazardous areas (EEHA). There may be differences between the content of this unit and AS/NZS 4761.1:2018, so the Standard must be checked to ensure compliance with it. Clause 2.15 of AS/NZS 4761.1:2018 includes the following precondition for assessment:

• “A candidate seeking assessment in this unit shall have been deemed competent to gather and analyse technical data in a relevant engineering or scientific discipline at AQF 7 or NZQF level 7(BD) or equivalent.”