Description

This Standard sets out requirements for the classification of areas where flammable gas or vapour risks might arise, in order to permit the proper selection and installation of electrical apparatus for use in such hazardous areas.

This Standard is for the use of manufacturers and installers of electrical equipment as well as by electrical inspecting authorities. It provides guidance to industries and statutory authorities concerned with the classification of hazardous areas.

Scope

This part of AS/NZS 60079 is concerned with the classification of areas where flammable gas or vapour or mist hazards may arise and may then be used as a basis to support the proper selection and installation of equipment for use in a hazardous area.

It is intended to be applied where there may be an ignition hazard due to the presence of flammable gas or vapour, mixed with air under normal atmospheric conditions, but it does not apply to

• a) mines susceptible to firedamp;
• b) the processing and manufacture of explosives;
• c) areas where a hazard may arise due to the presence of ignitable dusts or fibres (refer AS/NZS 61241/IEC 60079-10-2)
• d) catastrophic failures which are beyond the concept of abnormality dealt with in this standard;
• e) domestic premises.

This standard does not take into account the effects of consequential damage.

Definitions and explanations of terms are given together with the main principles and procedures relating to hazardous area classification.

For detailed recommendations regarding the extent of the hazardous areas in specific industries or applications, reference may be made to national or industry codes relating to those applications.

Attention is drawn to the fact that an area classified non-hazardous, in accordance with this Standard, may not necessarily be safe in all respects, e.g. toxic and chemical hazards.

Information on flammable mists is provided in Annex D.