question: what is the best approach how to consider it – Ex or non Ex?
experience says it makes sense to consider all Ex installations Ex even if it is installed outside of possible hazardous environment. In that case Ex integrity shall not verified / approved, if it goes back to any Ex zone again.
Any action shall be documented as per to other Ex zone installations.
keep up good work.
Arpad
exprofessional.com
Background With changes to the Type of Protection designations in the IEC
Those responsible for operating plants and processes where potentially explosive atmospheres exist
Source: LINK Each and every country has it regulated, but might be
“in some cases a zone of negligible extent (NE) may arise and
arpadveress 
