21 CFR § 189.300 - Hydrogenated 4,4′-isopropylidene-diphenolphosphite ester resins.
---
identifier: "/us/cfr/t21/s189.300"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 189.300 - Hydrogenated 4,4′-isopropylidene-diphenolphosphite ester resins."
title_number: 21
title_name: "Food and Drugs"
section_number: "189.300"
section_name: "Hydrogenated 4,4′-isopropylidene-diphenolphosphite ester resins."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "B"
subchapter_name: "FOOD FOR HUMAN CONSUMPTION"
part_number: "189"
part_name: "SUBSTANCES PROHIBITED FROM USE IN HUMAN FOOD"
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, 381."
regulatory_source: "42 FR 14659, Mar. 15, 1977, unless otherwise noted."
cfr_part: "189"
---
# 189.300 Hydrogenated 4,4′-isopropylidene-diphenolphosphite ester resins.
(a) Hydrogenated 4,4′-isopropylidene-diphenolphosphite ester resins are the condensation product of 1 mole of triphenyl phosphite and 1.5 moles of hydrogenated 4,4′-isopropylidene-diphenol such that the finished resins have a molecular weight in the range of 2,400 to 3,000. They are synthetic chemicals not found in natural products and have been used as antioxidants and as stabilizers in vinyl chloride polymer resins when such polymer resins are used in the manufacture of rigid vinyl chloride polymer bottles.
(b) Food containing any added or detectable levels of these substances is deemed to be adulterated and in violation of the Federal Food, Drug, and Cosmetic Act, based upon an order published in the *Federal Register* of September 9, 1987 (52 FR 33929).
[54 FR 7188, Feb. 17, 1989]