Code of Federal Regulations Title 21. Food and Drugs § 21.74.2101 FD&C Blue No. 1

(a) Identity. The color additive FD&C Blue No. 1 is principally the disodium salt of ethyl[4–[ p –[ethyl(m–sulfobenzyl)amino]–α–(o –sulfophenyl) benzylidene]–2,5–cyclohexadien–1–ylidene](m –sulfobenzyl)ammonium hydroxide inner salt with smaller amounts of the isomeric disodium salts of ethyl[4–[ p –[ethyl(p –sulfobenzyl)amino]–α–(o –sulfophenyl) benzylidene]–2,5–cyclohexadien–1–ylidene](p –sulfobenzyl)ammonium hydroxide inner salt and ethyl[4–[ p –[ethyl(o–sulfobenzyl)amino]–α–(o –sulfophenyl) benzylidene]–2,5–cyclohexadien–1–ylidene](o –sulfobenzyl)ammonium hydroxide inner salt. Additionally, FD&C Blue No. 1 is manufactured by the acid catalyzed condensation of one mole of sodium 2–formylbenzenesulfonate with two moles from a mixture consisting principally of 3–[(ethylphenylamino)methyl] benzenesulfonic 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, or with manganese dioxide and acid to form the dye. The intermediate sodium 2–formylbenzenesulfonate is prepared from 2–chlorobenzaldehyde and sodium sulfite.

(b) Specifications.

(c) Uses and restrictions.

(d) Labeling. The label of the color additive shall conform to the requirements of § 70.25 of this chapter.

(e) Certification. All batches of FD&C Blue No. 1 shall be certified in accordance with regulations in part 80 of this chapter.