21 CFR § 184.1265 - Cuprous iodide.
---
identifier: "/us/cfr/t21/s184.1265"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 184.1265 - Cuprous iodide."
title_number: 21
title_name: "Food and Drugs"
section_number: "184.1265"
section_name: "Cuprous iodide."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "B"
subchapter_name: "FOOD FOR HUMAN CONSUMPTION"
part_number: "184"
part_name: "DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE"
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, 342, 348, 371."
regulatory_source: "42 FR 14653, Mar 15, 1977, unless otherwise noted."
cfr_part: "184"
---
# 184.1265 Cuprous iodide.
(a) Cuprous iodide (copper (I) iodide, CuI, CAS Reg. No. 7681-65-4) is a pure white crystalline powder. It is prepared by the reaction of copper sulfate with potassium iodide under slightly acidic conditions.
(b) The ingredient must be of a purity suitable for its intended use.
(c) In accordance with § 184.1(b)(2), the ingredient is used in food only within the following specific limitations:
| Category of food | Maximum treatment level in food | Functional use |
| --- | --- | --- |
| Table salt | 0.01 percent | Source of dietary iodine. |
(d) Prior sanctions for this ingredient different from the uses established in this section do not exist or have been waived.
[49 FR 24119, June 12, 1984, as amended at 73 FR 8607, Feb. 14, 2008]