[Code of Federal Regulations]
 [Title 21, Volume 1]
 [Revised as of April 1, 2002]
 From the U.S. Government Printing Office via GPO Access
 [CITE: 21CFR74.203]
 
 [Page 392-393]
 
                         TITLE 21--FOOD AND DRUGS
 
 CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
                                 SERVICES
 
 PART 74--LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION--Table of Contents
 
                             Subpart A--Foods
 
 Sec. 74.203  FD&C Green No. 3.
 
     (a) Identity. (1) The color additive FD&C Green No. 3 is principally
 the inner salt disodium salt of N-ethyl-N-[4-[[4-[ethyl[(3-
 sulfophenyl)methyl]amino]phenyl](4-hydroxy-2-sulfophenyl)methylene]-2,5-
 cyclohexadien-1-ylidene]-3-sulfobenzenemethanaminium hydroxide (CAS Reg.
 No. 2353-45-9); with smaller amounts of the isomeric inner salt disodium
 salt of N-ethyl-N-[4-[[4-[ethyl[(3-sulfophenyl)methyl] amino]phenyl](4-
 hydroxy-2-sulfophenyl)methylene]-2,5-
 
 [[Page 393]]
 
 cyclohexadien-1-ylidene]-4-sulfobenzenemethanaminium hydroxide; of N-
 ethyl-N-[4-[[4-[ethyl[(4-sulfophenyl)methyl]amino]phenyl](4-hydroxy-2-
 sulfophenyl)methylene]-2,5-cyclohexadien-1-ylidene]-4-
 sulfobenzenemethanaminium hydroxide and of N-ethyl-N-[4-[[4-[ethyl[(2-
 sulfophenyl)methyl]amino]phenyl](4-hydroxy-2-sulfophenyl)methylene]-2,5-
 cyclohexadien-1-ylidene]-3-sulfobenzenemethanaminium hydroxide.
 Additionally, FD&C Green No. 3 is manufactured by the acid catalyzed
 condensation of one molecule of 2-formyl-5-hydroxybenzenesulfonic acid
 with two molecules from a mixture consisting principally of 3-
 [(ethylphenylamino)methyl]
 
 benzensulfonic acid, and smaller amounts of 4-[(ethylphenylamino)methyl]
 
 benzenesulfonic acid and 2-[(ethylphenylamino)methyl]
 
 benzenesulfonic acid to form the leuco base. The leuco base is then
 oxidized with lead dioxide and acid or with dichromate and acid to form
 the dye. The intermediate 2-formyl-5-hydroxybenzenesulfonic acid is
 prepared by the potassium permanganate oxidation of 2,2'-(1,2-
 ethenediyl)-bis(5-aminobenzenesulfonic acid) to sodium 5-amino-2-
 formylbenzenesulfonate. This amine is diazotized and the resulting
 diazonium salt is hydrolyzed to the desired 2-formyl-5-
 hydroxybenzenesulfonic acid.
     (2) Color additive mixtures for food use (including dietary
 supplements) made with FD&C Green No. 3 may contain only those diluents
 that are suitable and that are listed in part 73 of this chapter as safe
 for use in color additive mixtures for coloring food.
     (b) Specifications. The color additive FD&C Green No. 3 shall
 conform to the following specifications and shall be free from
 impurities other than those named to the extent that such other
 impurities may be avoided by current good manufacturing practice:
 
 Sum of volatile matter at 135 deg.C (275 deg.F) and chlorides and
 sulfates (calculated as sodium salts), not more than 15 percent.
 Water-insoluble matter, not more than 0.2 percent.
 Leuco base, not more than 5 percent.
 Sum of 2-,3-,4-formylbenzenesulfonic acids, sodium salts, not more than
 0.5 percent.
 Sum of 3- and 4-[[ethyl(4-sulfophenyl)amino]methyl] benzenesulfonic
 acid, disodium salts, not more than 0.3 percent.
 2-Formyl-5-hydroxybenzenesulfonic acid, sodium salt, not more than 0.5
 percent.
 Subsidiary colors, not more than 6 percent.
 Chromium (as Cr), not more than 50 parts per million.
 Arsenic (as As), not more than 3 parts per million.
 Lead (as Pb), not more than 10 parts per million.
 Mercury (as Hg), not more than 1 part per million.
 Total color, not less than 85 percent.
 
     (c) Uses and restrictions. The color additive FD&C Green No. 3 may
 be safely used for coloring foods (including dietary supplements)
 generally in amounts consistent with current good manufacturing practice
 except that it may not be used to color foods for which standards of
 identity have been promulgated under section 401 of the act unless added
 color is authorized by such standards.
     (d) Labeling. The label of the color additive and any mixtures
 prepared therefrom intended solely or in part for coloring purposes
 shall conform to the requirements of Sec. 70.25 of this chapter.
     (e) Certification. All batches of FD&C Green No. 3 shall be
 certified in accordance with regulations in part 80 of this chapter.
 
 [47 FR 52143, Nov. 19, 1982; 47 FR 56489, Dec. 17, 1982]