This part of AS/NZS 60079 contains the specific requirements for the design, selection and erection of electrical installations in hazardous areas associated with explosive atmospheres.

Where the equipment is required to meet other environmental conditions, for example, protection against ingress of water and resistance to corrosion, additional methods of protection may be necessary. The method used shall not adversely affect the integrity of the enclosure.

The requirements of this Standard apply only to the use of equipment under normal or near normal atmospheric conditions. For other conditions, additional precautions may be necessary. For example, most flammable materials and many materials which are normally regarded as non-flammable might burn vigorously under conditions of oxygen enrichment. Other precautions might also be necessary in the use of equipment under conditions of extreme temperature and pressure. Such precautions are beyond the scope of this Standard.

The requirements specified in this Standard are supplementary to and not alternative to any requirements given in AS/NZS 3000. Any alterations or modifications to AS/NZS 3000 in this document are specifically stated.

This Standard applies to all electrical equipment including fixed, portable, transportable and personal, and installations, permanent or temporary.

It applies to installations at all voltages.

This Standard does not apply to

– inherently explosive situations and dust from explosives or pyrophoric substances (for example explosives manufacturing and processing);

– rooms used for medical purposes;

– other than group I, electrical installations in areas where the hazard is due to hybrid mixtures of combustible dust and explosive gas, vapour or mist.

No account is taken in this Standard of the toxic risks that are associated with most flammable gasses and liquids in concentrations that are usually very much less than the lower explosive limit. In locations where personnel may be exposed to potentially toxic concentrations of flammable material, appropriate precautions should be taken. Such precautions are outside the scope of this Standard. This Standard also does not take into account of any risk due to an emission of flammable or toxic gas fromdusts.

NOTE For further information, refer to the relevant departments/authorities in New Zealand or in each Australian State.