This part of IEC 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 should 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. The significant technical changes with respect to the previous edition are: Equipment Protection Levels (EPLs) have been introduced and are explained in the new Annex I and dust requirements included from IEC 61241 14, Ed. 1.0.