[Code of Federal Regulations]
[Title 21, Volume 1]
[Revised as of April 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR74.102]

[Page 392]
 
                        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. 74.102  FD&C Blue No. 2.

    (a) Identity. (1) The color additive FD&C Blue No. 2 is principally 
the disodium salt of 2-(1,3-dihydro-3-oxo-5-sulfo-2H-indol-2-ylidene)-
2,3-dihydro-3-oxo-1H-indole-5-sulfonic acid (CAS Reg. No. 860-22-0) with 
smaller amounts of the disodium salt of 2-(1,3-dihydro-3-oxo-7-sulfo-2H-
indol-2-ylidene)-2,3-dihydro-3-oxo-1H-indole-5-sulfonic acid (CAS Reg. 
No. 54947-75-0) and the sodium salt of 2-(1,3-dihydro-3-oxo-2H-indol-2-
ylidene)-2,3-dihydro-3-oxo-1H-indole-5-sulfonic acid (CAS Reg. No. 605-
18-5). Additionally, FD&C Blue No. 2 is obtained by heating indigo (or 
indigo paste) in the presence of sulfuric acid. The color additive is 
isolated and subjected to purification procedures. The indigo (or indigo 
paste) used above is manufactured by the fusion of N-phenylglycine 
(prepared from aniline and formaldehyde) in a molten mixture of sodamide 
and sodium and potassium hydroxides under ammonia pressure. The indigo 
is isolated and subjected to purification procedures prior to 
sulfonation.
    (2) Color additive mixtures for food use (including dietary 
supplements) made with FD&C Blue No. 2 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 foods.
    (b) Specifications. The color additive FD&C Blue No. 2 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 0.4 percent.
Isatin-5-sulfonic acid, not more than 0.4 percent.
5-Sulfoanthranilic acid, not more than 0.2 percent.
Disodium salt of 2-(1,3-dihydro-3-oxo-7-sulfo-2H-indol-2-ylidene)-2,3-
dihydro-3-oxo-1H-indole-5-sulfonic acid, not more than 18 percent.
Sodium salt of 2-(1,3-dihydro-3-oxo-2H-indol-2-ylidene)-2,3-dihydro-3-
oxo-1H-indole-5-sulfonic acid, not more than 2 percent.
Lead (as Pb), not more than 10 parts per million.
Arsenic (as As), not more than 3 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 Blue No. 2 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 Federal Food, Drug, and 
Cosmetic 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 Blue No. 2 shall be certified 
in accordance with regulations in part 80 of this chapter.

[48 FR 5260, Feb. 4, 1983]