S.C. Code Ann. Regs. 5-207
(1) A “Custom-Mixed Feed” shall be labeled by invoice. The invoice, which is to accompany delivery and be supplied to the purchaser at the time of delivery, shall bear the following information:
(2) A “Customer Formula Feed” shall be labeled by invoice. The invoice, which is to accompany delivery and be supplied to the purchaser at the time of delivery shall bear the following information:
(3) Urea and other nonprotein nitrogen products as defined in the AAFCO publication are acceptable ingredients in commercial feeds for ruminant animals and shall not be used in commercial feeds for other animals and birds as sources of equivalent crude protein.
The maximum percentage of equivalent crude protein from added nonprotein nitrogen shall appear immediately below the guarantee for total crude protein.
If the commercial feed contains more than 8.75% of equivalent crude protein from all forms of nonprotein nitrogen, added as such, or if the equivalent crude protein from all forms of nonprotein nitrogen, added as such, exceeds one third of the total crude protein, the label shall bear adequate directions for the safe use of such feeds and the statement:
“CAUTION: Use as directed.”
The directions for use and the caution statement shall be in type of such size so that they will be read and understood by ordinary persons under customary conditions of purchase and use.
On labels such as those for medicated feeds which bear adequate feeding directions and/or warning statements, the presence of added nonprotein nitrogen products shall not require a duplication of feeding directions or the warning statements.