19 CFR §19.8

Importers may, upon application approved by the port director on Customs Form 3499 examine, sample, and repack 12 or transfer merchandise in bonded warehouse. Where there will be no interference with the orderly conduct of Customs business and no danger to the revenue prospective purchaser may be permitted to examine merchandise in bonded warehouses upon the written request of the owner, importer, consignee, or transferee.