[Code of Federal Regulations]
[Title 21, Volume 1]
[Revised as of April 1, 2006]
From the U.S. Government Printing Office via GPO Access
TITLE 21--FOOD AND DRUGS
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
PART 74_LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION--Table of
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
(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]
Additives that reference this regulation: