A UN marking describes the package as a tested combination — container, closure, gasket and often the liner together. Swapping any part can invalidate it. Whether a specific product requires a UN-rated package is a regulatory question for the shipper and the carrier, not a packaging preference.
Where you meet this term
If this becomes a real requirement
CAQUIN sources industrial packaging to specification. Send what you use today, roughly how much, and where it ships — a photo is enough to start.