arpadveress 
A hazardous area installation shall be Ex certified. Certification may come from manufacturer or 3rd party Notified Body.
What about the site? Shall it be Ex certified? Is there any Ex certification related to hazardous area site?
No. Back in Europe ATEX 137 defines all requirements for Ex safe operation shall be documented in an Explosion Protection Documentation.
Just received the question:
“We are a chemical factory. Our clients wish to see the hazardous area certification of the site.”
See above.
Keep up good work.
Arpad
