On-site failures with stainless steel cleanroom panels​ rarely start as material defects alone. Most trace back to incorrect grade selection, untreated cut edges, carbon-steel cross-contamination, poor sealant compatibility, weld passivation skip, film left too long, core delamination, and weak joint sealing that later fails cleanroom acceptance. This FAQ gives procurement engineers, cleanroom contractors and pharma/food GMP builders a fast diagnostic checklist for stainless steel cleanroom panels, with repair priorities aligned to medical, lab, food and pharmaceutical enclosures.