When a sample of an article offered for import has been requested by the division director, FDA shall provide to the owner or consignee prompt notice of delivery of, or intention to deliver, such sample. Upon receipt of the notice, the owner or consignee shall hold such article and not distribute it until further notice from the division director or U.S. Customs and Border Protection of the results of examination of the sample.
21 C.F.R. §1.90