21 CFR § 176.320 - Sodium nitrate-urea complex.

---
identifier: "/us/cfr/t21/s176.320"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 176.320 - Sodium nitrate-urea complex."
title_number: 21
title_name: "Food and Drugs"
section_number: "176.320"
section_name: "Sodium nitrate-urea complex."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "B"
subchapter_name: "FOOD FOR HUMAN CONSUMPTION"
part_number: "176"
part_name: "INDIRECT FOOD ADDITIVES: PAPER AND PAPERBOARD COMPONENTS"
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, 346, 348, 379e."
regulatory_source: "42 FR 14554, Mar. 15, 1977, unless otherwise noted."
cfr_part: "176"
---


# 176.320 Sodium nitrate-urea complex.

Sodium nitrate-urea complex may be safely used as a component of articles intended for use in producing, manufacturing, packing, processing, preparing, treating, packaging, transporting, or holding food, subject to the provisions of this section.

(a) Sodium nitrate-urea complex is a clathrate of approximately two parts urea and one part sodium nitrate.

(b) Sodium nitrate-urea complex conforming to the limitations prescribed in paragraph (b)(1) of this section is used as provided in paragraph (b)(2) of this section.

(1) *Limitations.* (i) It is used as a plasticizer in glassine and greaseproof paper.

(ii) The amount used does not exceed that required to accomplish its intended technical effect or exceed 15 percent by weight of the finished paper.

(2) *Conditions of use.* The glassine and greaseproof papers are used for packaging dry food or as the food-contact surface for dry food.