After an individual shipment of imported flue-cured or burley tobacco has been sampled, regardless of whether it is certified as being free from prohibited peticide residues, it must be kept in the original packages, and not be mixed, blended, manipulated, or altered in any manner, or moved, shipped, or transported from the point of entry until it has been determined that the tobacco does not contain prohibited pesticide residues.
7 C.F.R. §29.431