In July 2006, the European Union issued a directive to all manufacturers and users of equipment in hazardous areas called the ATEX Directive. The aim of directive is to allow the free trade of 'ATEX' certified equipment and protective systems within the EU by removing the need for separate testing and documentation for each member state.
Outside of the EU, compliance to the ATEX directive is not mandatory. In Australia, ATEX certifited Ex equipment not certified to the ANZEx/AUSEx or IECEx schemes, is not allowed to be installed unless accompanied by a Conformity Assessment Document (CAD). The equipment CAD provides an equivalent level of safety to the ANZEx/AUSEx or IECEx schemes. FM, CSA, UL or other Ex equipment not certified to the ANZEx/AUSEx or IECEx schemes are likewise required to obtain CAD for the equipment.
What does this mean? It means that only equipment certified to the ANZEx/AUSEx or IECEx schemes need to be installed without further requirement.