ATEX 2014-34-EU Guidelines - 2nd Edition December 2017 Borderline

few more you will be able to find here. specially the non-electrical assemblies might be very interesting ones...

+more: what about watches?

A basic electronic wrist watch is an example of a low voltage, electronic device which has been independently evaluated and found to be acceptable for use in a hazardous area under both historic and current EPL requirements. (EN 60079-14)