TTB and FDA limited ingredients must be identified in the formulation regardless of the source. This means that limited ingredients from in-house and purchased products must be listed and quantified. This can be done by simply listing the percent by weight of each limited ingredient for each intermediate formulation listed. Frequently, this information can be obtained from the manufacturer's specification sheet or Flavor Ingredient Data Sheet (FIDS). If submitting a specification sheet, be sure that information about the presence or absence of limited ingredients is included. Otherwise, the specification sheet is of no value.
The list of TTB and FDA limited ingredients can be found here.
The following is an example of a correctly stated line item in box 13:
Chickory Solid Extract (10% PG by wt)…………………..0.9 lbs
A large percentage of formulas have been returned by TTB officers requesting additional information regarding presence of limited ingredients and color in several types of intermediates. If you know your intermediates (essences, distillates, solid extracts, etc) do not contain limited ingredients nor color, please state that in the formula to avoid unnecessary returns. If they contain limited ingredients disclose the amounts present in each intermediate. If they contain color disclose the color in each intermediate.