Contains specific requirements for the construction and assessment of intrinsically safe electrical systems, type of protection "i", intended for use, as a whole or in part, in explosive atmospheres in Group II locations. Is intended for use by the designer of the system who may be a manufacturer, a specialist consultant or a member of the end-user's staff. This standard supplements SANS 60079-11, the requirements of which apply to electrical apparatus used in intrinsically safe electrical systems. The installation requirements of a Group II system designed in accordance with this standard are specified in SANS 60079-14.