Each and every industry has its Ex hazardous relevance – storage, handling of chemicals, loading / unloading, MoC of technologies, updates, and many more.
There are methodologies and few are valid in all cases.
Ignition hazard assessment shall be done with Ex certified products while under design stage, but even if installation ongoing. Similar shall be done while operation, but repair / overhaul not far away from it either.
Keep up good work!