Section 184.1307b - Ferrous carbonate(a) Ferrous carbonate (iron (II) carbonate, FeCO3, CAS Reg. No. 563-71-3) is an odorless, white solid prepared by treating solutions of iron (II) salts with alkali carbonate salts.(b) The ingredient must be of a purity suitable for its intended use.(c) In accordance with § 184.1(b)(1) , the ingredient is used in food as a nutrient supplement as defined in § 170.3(o)(20) of this chapter, with no limitation other than current good manufacturing practice. The ingredient may also be used in infant formula in accordance with section 412(g) of the Federal Foods, Drug, and Cosmetic Act (the act) (21 U.S.C. 350a(g) ) or with regulations promulgated under section 412(a)(2) of the act (21 U.S.C. 350a(a)(2) ).(d) Prior sanctions for this ingredient different from the uses established in this section do not exist or have been waived.53 FR 16865, May 12, 1988, as amended at 73 FR 8607 , Feb. 14, 2008