For big 'uns like Southern Pride, Cookshack, etc. you'd need UL approval for the wiring - I know the FEC500 and FEC750 are NSF and UL approved.
Most other cookers have not been offered up for inspection - both UL and NSF are voluntary...though well worth it for the commercial builders that expect their equipment to be used "indoors".
Clean would be the main consideration - assuming an inspector ever tracked you down.
Southern Brethren BBQ Competition Team
"It's all about getting paid!" - Myron Mixon
"I love being hated in my hometown!" - David Hair
KingFisher Gator Rotisserie cooker, WSM, Stainless 5 burner with IR gas grill, Turkey Fryer, Weber JD Commemorative grill, slightly used Bandera chamber for future use as a cold smoker, Masterbuilt 40" insulated ELECTRIC smoker