S.C. Code § 46-25-30
Until the commission prescribes the alternative form of "guaranteed analysis", the term "guaranteed analysis" shall mean the minimum percentage of plant nutrients claimed in the following order and form:
Total nitrogen (N) | percent |
Available phosphoric acid (P(2)O(5)) | percent |
Soluble potash (K(2)O) | percent |
When the commission finds, after public hearing following due notice, that the requirement for expressing the guaranteed analysis of phosphorus and potassium in elemental form would not impose an economic hardship on distributors and users of fertilizer by reason of conflicting labeling requirements among the states, it may require by regulation thereafter that the guaranteed analysis shall be in the following form:
Total nitrogen (N) | percent |
Available phosphorus (P) | percent |
Soluble potassium (K) | percent |
The effective date of the regulation shall not be less than six months following the issuance thereof and for a period of two years following the effective date of the regulation the equivalent of phosphorus and potassium may also be shown in the form of phosphoric acid and potash. After the effective date of a regulation issued under the provisions of this section, requiring that phosphorus and potassium be shown in the elemental form, the guaranteed analysis for nitrogen, phosphorus and potassium shall constitute the grade.
For unacidulated mineral phosphatic materials and basic slag, bone, tankage and other organic phosphate materials, the total phosphoric acid and degree of fineness may also be guaranteed.
Guarantees for other plant nutrients other than nitrogen, phosphorus, and potassium may be permitted or required by regulation of the commission. The guarantees for other such nutrients must be expressed in the form of the element. The sources of such other nutrients (oxides, salt, chelates, etc.) are required upon registration and may be included as a parenthetical statement on the label. Other beneficial substances or compounds, determinable by laboratory methods, also may be guaranteed by permission of the commission. When any plant nutrients or other substances or compounds are guaranteed, they are subject to inspection and analysis in accord with the methods and regulations prescribed by the commission.
In fertilizers designated for use in tobacco products, the chlorine content must be guaranteed by the registrant at the time of registration to comply with existing regulations promulgated under authority of this chapter. A change in the chlorine content must be reported immediately to the commission.
The commission may require proof of claims made for any fertilizer. If no claims are made, proof of usefulness and value of the fertilizer may be required. For evidence of proof, the commission may rely on scientifically- accepted, experimental data and evaluations. The experimental design must be related to conditions applicable to South Carolina. The commission may request assistance from the Director of the Clemson Experiment Station or the Director of the Cooperative Extension Service or persons under their supervision for interpretation of data and for advice of the acceptability of data. Scientific data from any source may be used by the commission as a basis for acceptance or rejection of claims.
S.C. Code § 46-25-30