arpadveress 
how does it work?
a decade ago we had sheeps around to do the job. now it is less applicable: animal protection, environmental protection, and similar. all fine.
so how does it work now? how you do it?
we all shall agree most of the “green” fields around / inside of refineries, chemical facilities and similar are Ex zones. most probably Zone 2 / 22 (subject to hazardous area classification).
options see below:
a topic not yet fully examined. So a job to do for Ex professionals.
Keep up the good work!
