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74.102 FD&C Blue No. 2.

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[Code of Federal Regulations]

[Title 21, Volume 1]

[Revised as of April 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 21CFR74.102]

[Page 387-388]


                        TITLE 21--FOOD AND DRUGS








                             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 


    (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

[[Page 388]]

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:

Source: U.S. Code of Federal Regulations - CFR Title 21, Part 74, Section 102

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