UL vs CE Marking

The UL Listing and CE marking are two completely different kinds of product evaluations.

UL Listing: An independent Type Testing and certification when product meet applicable North American, UL & ANSI requirements depending on the declared application.
Prerequisites: Critical components used in an end product like SMPS or Controller should be UL Listed / Recognized and selected of the correct rating with respect to end product requirements.
Please specify: Normal Area use / hazardous area use? if individual components like SMPS, GPRS modem etc. are bought out items?

CE Marking: is a self declared marking after testing to the requirements of applicable directives. If used in Zone 1 or higher hazardous areas, ATEX directive compliance needs to be strictly issued by Notified Body like UL. RF Testing will be needed for wireless components unless previously tested and labelled.