ATEX, IECEx and UL are not interchangeable versions of one lighting rating. A project may require one or several approvals, depending on its jurisdiction, site specification and equipment configuration.
ATEX concerns EU conformity
Directive 2014/34/EU governs equipment and protective systems intended for potentially explosive atmospheres placed on the EU market. The required conformity-assessment procedure depends on the equipment and category. Check the declaration, marking, applicable documentation and any conditions for the exact product.
IECEx provides an international certification scheme
IECEx equipment certification uses recognized certification bodies and a public certificate system. Check the certificate's status, model scope and special conditions. IECEx certification can support international procurement, but local acceptance still needs to be established for the project.
North American acceptance uses its own requirements
For U.S. and Canadian work, examine the applicable certification marks, Class/Division or Zone marking and installation rules. UL is a certification organization as well as a standards developer; another recognized laboratory can certify products within its recognized scope. A reference to UL 844 alone is not proof of an exact-model listing.
Read a multi-approved light one marking at a time
A product can carry several approvals without every configuration sharing identical limits. Compare model suffixes, supply, gas and dust groups, temperature class, ambient range and installation conditions. Do not translate Class I, Division 1 directly into Zone 0 or infer dust approval from a gas marking.
Make the submittal specific
Provide the full ordering code, configuration, certificate references and instructions for the equipment being offered. Resolve any mismatch between the selected assembly and available paperwork before use. This is especially important when a transformer, plug or cable option changes the complete electrical arrangement.
References: European Commission — Equipment for potentially explosive atmospheres · IECEx — Equipment certification questions · UL Solutions — North American hazardous-area certification · OSHA 1910.307 — Hazardous (classified) locations