scope:

This part of IEC 60079 specifies the general requirements for construction, testing and marking of electrical apparatus and Ex components intended for use in explosive gas atmospheres.

Unless modified by one of the parts in the IEC 60079 series, electrical apparatus complying with this standard is intended for use in hazardous areas in which explosive gas atmospheres, caused by mixtures of air and gases, vapours or mists, exist under normal atmospheric conditions of

 • temperature -20 °C to +60 °C;

 • pressure 80 kPa (0,8 bar) to 110 kPa (1,1 bar); and

 • air with normal oxygen content, typically 21 % v/v.

The application of electrical apparatus in atmospheric conditions outside this range may need special consideration.

As the requirements of IEC 60079 series Standards cover the protection techniques with respect to explosion hazard only, the CAN/CSA-E60079 series of CSA Standards (based on the corresponding IEC Standards) must be used in conjunction with other applicable standards containing the appropriate electrical safety requirements for general use equipment.