21 CFR § 172.490 - Yellow prussiate of soda.

---
identifier: "/us/cfr/t21/s172.490"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 172.490 - Yellow prussiate of soda."
title_number: 21
title_name: "Food and Drugs"
section_number: "172.490"
section_name: "Yellow prussiate of soda."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "B"
subchapter_name: "FOOD FOR HUMAN CONSUMPTION"
part_number: "172"
part_name: "FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION"
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, 348, 371, 379e."
regulatory_source: "42 FR 14491, Mar. 15, 1977, unless otherwise noted."
cfr_part: "172"
---


# 172.490 Yellow prussiate of soda.

(a) The food additive yellow prussiate of soda (sodium ferrocyanide decahydrate; Na<sub>4</sub>Fe(CN)<sub>6</sub>·10H<sub>2</sub>O contains a minimum of 99 percent by weight of sodium ferrocyanide decahydrate.

(b) The additive is used or intended for use as an anticaking agent in salt and as an adjuvant in the production of dendritic crystals of salt in an amount needed to produce its intended effect but not in excess of 13 parts per million calculated as anhydrous sodium ferrocyanide.

[42 FR 14491, Mar. 15, 1977, as amended at 58 FR 17098, Apr. 1, 1993]