27 C.F.R. § 20.95
(b) Samples for shipment to prospective customers. Prior to submitting a formula and statement of process on TTB Form 5150.19, a user may use S.D.S. to prepare developmental samples of articles for shipment to prospective customers. Only one sample of each formulation of the article under development may be sent to each customer. Each sample shall be no larger than necessary for the customer to determine whether the product meets its requirements. The user shall maintain records showing:
(c) Formula requirement. Before the user begins to make a quantity greater than specified in this section, formula approval on TTB Form 5150.19 is required.
(Approved by the Office of Management and Budget under control number 1513-0062)
[T.D. TTB-140, 81 FR 59456, Aug. 30,2016]