UPS box smoker

What kinds of parts MIGHT have it? As I said, I will use stainless steel racks.

Good advice, but:

Remember this is a smoker. Temp inside shouldn't go above 200 F

I'd sure make sure my shelves are cadimum free, but the stuff which isn't in contact with the meat is less critical at those temperatures.

If OP is really concerned about possible contamination, I'd spray the inside with high-temp paint and let it cure throughly before use.

--RC "Sometimes history doesn't repeat itself. It just yells 'can't you remember anything I've told you?' and lets fly with a club. -- John W. Cambell Jr.