Section 184.1537 - Nickel(a) Elemental nickel (CAS Reg. No. 7440-02-0) is obtained from nickel ore by transforming it to nickel sulfide (Ni3S2). The sulfide is roasted in air to give nickel oxide (NiO). The oxide is then reduced with carbon to give elemental nickel.(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 with no limitation other than current good manufacturing practice. The affirmation of this ingredient as generally recognized as safe (GRAS) as a direct human food ingredient is based upon the following current good manufacturing practice conditions of use: (1) The ingredient is used as a catalyst as defined in § 170.3(o)(24) of this chapter.(2) The ingredient is used in the hydrogenation of fats and oils as defined in § 170.3(n)(12) of this chapter at levels not to exceed current good manufacturing practice. Current good manufacturing practice includes the removal of nickel from fats and oils following hydrogenation.(d) Prior sanctions for this ingredient different from the uses established in this section do not exist or have been waived.48 FR 51618, Nov. 10, 1983, as amended at 73 FR 8607 , Feb. 14, 2008