21 CFR § 573.496 - Guanidinoacetic acid.
The food additive, guanidinoacetic acid, may be safely used in poultry feeds in accordance with the following prescribed conditions:
(a) The additive is manufactured by reacting glycine with cyanamide in an aqueous solution.
(b) The additive is used or intended for use at levels not to exceed 0.12 percent of the complete feed:
(1) To spare arginine in broiler chicken and turkey feeds; or
(2) As a precursor of creatine in poultry feeds.
(c) The additive consists of not less than 97 percent guanidinoacetic acid [N-(aminoiminomethyl)-glycine] (CAS 352–97–6) by weight.
(d) The additive meets the following specifications:
(1) Dicyandiamide not to exceed 0.5 percent;
(2) Cyanamide not to exceed 0.01 percent;
(3) Melamine not to exceed 15 parts per million (ppm);
(4) Sum of ammeline, ammelide, and cyanuric acid not to exceed 35 ppm; and
(5) Water not to exceed 1 percent.
(e) To assure safe use of the additive in addition to the other information required by the Federal Food, Drug, and Cosmetic Act:
(1) The label and labeling of the additive, any feed premix, and complete feed shall contain the name of the additive.
(2) The label and labeling of the additive and any feed premix shall also contain:
(i) A statement to indicate the maximum use level of guanidinoacetic acid must not exceed 0.12 percent of the complete feed for poultry; and
(ii) Adequate directions for use.