21 CFR § 74.1306 - D&c Red No. 6.

---
identifier: "/us/cfr/t21/s74.1306"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 74.1306 - D&C Red No. 6."
title_number: 21
title_name: "Food and Drugs"
section_number: "74.1306"
section_name: "D&C Red No. 6."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "A"
subchapter_name: "GENERAL"
part_number: "74"
part_name: "LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "21 U.S.C. 321, 341, 342, 343, 348, 351, 352, 355, 361, 362, 371, 379e."
regulatory_source: "42 FR 15654, Mar. 22, 1977, unless otherwise noted."
cfr_part: "74"
---


# 74.1306 D&C Red No. 6.

(a) *Identity.* (1) The color additive D&C Red No. 6 is principally the disodium salt of 3-hydroxy-4-[(4-methyl-2-sulfophenyl)azo]-2-naphthalenecarboxylic acid (CAS Reg. No. 5858-81-1). To manufacture the additive, 2-amino-5-methylbenzenesulfonic acid is diazotized with hydrochloric acid and sodium nitrite. The diazo compound is coupled in alkaline medium with 3-hydroxy-2-naphthalenecarboxylic acid. The resulting dye precipitates as the disodium salt.

(2) Color additive mixtures for drug use made with D&C Red No. 6 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 drugs.

(b) *Specifications.* The color additive D&C Red No. 6 shall conform to the following specifications and shall be free from impurities other than those named to the extent that such impurities may be avoided by current good manufacturing practice:

Sum of volatile matter (at 135 °C) and chlorides and sulfates (calculated as sodium salts), not more than 10 percent.

1-[(4-methylphenyl)azo]-2-naphthalenol, not more than 0.015 percent.

2-Amino-5-methylbenzenesulfonic acid, sodium salt, not more than 0.2 percent.

3-Hydroxy-2-naphthalenecarboxylic acid, sodium salt, not more than 0.4 percent.

3-Hydroxy-4-[(4-methylphenyl)azo]-2-naphthalenecarboxylic acid, sodium salt, not more than 0.5 percent.

*p-* Toluidine, not more than 15 parts per million.

Lead (as Pb), not more than 20 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 90 percent.

(c) *Uses and restrictions.* The color additive D&C Red No. 6 may be safely used for coloring drugs such that the combined total of D&C Red No. 6 and D&C Red No. 7 does not exceed 5 milligrams per daily dose of the drug.

(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 § 70.25 of this chapter.

(e) *Certification.* All batches of D&C Red No. 6 shall be certified in accordance with regulations in part 80 of this chapter.

[47 FR 57687, Dec. 28, 1982, as amended at 77 FR 39923, July 6, 2012]