21 C.F.R. § 74.1339 – D&C Red No. 39.

(a) Identity.
1. (1) The color additive D&C Red No. 39 is o-[p(β,β′-dihydroxy-diethylamino)-phenylazo]-benzoic acid.
2. (2) Color additive mixtures made with D&C Red No. 39 may contain the following diluents: Water, acetone, isopropyl alcohol, and specially denatured alcohols used in accordance with 26 CFR part 212.
(b) Specifications. D&C Red No. 39 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 good manufacturing practice:
Volatile matter (at 100 °C.), not more than 2.0 percent. Matter insoluble in acetone, not more than 1.0 percent. Anthranilic acid, not more than 0.2 percent. N,N-(β,β′-Dihydroxy-diethyl) aniline, not more than 0.2 percent. Subsidiary colors, not more than 3.0 percent. Lead (as Pb), not more than 20 parts per million. Arsenic (as As), not more than 3 parts per million. Total color, not less than 95.0 percent.
(c) Uses and restrictions. The color additive D&C Red No. 39 may be safely used for the coloring of quaternary ammonium type germicidal solutions intended for external application only, and subject to the further restriction that the quantity of the color additive does not exceed 0.1 percent by weight of the finished drug product.
(d) Labeling. The label of the color additive and any mixtures prepared therefrom and intended solely or in part for coloring purposes shall conform to the requirements of § 70.25 of this chapter.
(e) Certification. All batches of D&C Red No. 39 shall be certified in accordance with regulations promulgated under part 80 of this chapter.