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21 CFR § 177.1345 - Ethylene/1,3-phenylene oxyethylene isophthalate/ terephthalate copolymer.

---
identifier: "/us/cfr/t21/s177.1345"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 177.1345 - Ethylene/1,3-phenylene oxyethylene isophthalate/ terephthalate copolymer."
title_number: 21
title_name: "Food and Drugs"
section_number: "177.1345"
section_name: "Ethylene/1,3-phenylene oxyethylene isophthalate/ terephthalate copolymer."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "B"
subchapter_name: "FOOD FOR HUMAN CONSUMPTION"
part_number: "177"
part_name: "INDIRECT FOOD ADDITIVES: POLYMERS"
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, 379e."
regulatory_source: "42 FR 14572, Mar. 15, 1977, unless otherwise noted."
cfr_part: "177"
---

# 177.1345 Ethylene/1,3-phenylene oxyethylene isophthalate/ terephthalate copolymer.

Ethylene/1,3-phenylene oxyethylene isophthalate/terephthalate copolymer (CAS Reg. No. 87365-98-8) identified in paragraph (a) of this section may be safely used, subject to the provisions of this section, as the non-food-contact layer of laminate structures subject to the provisions of § 177.1395, and in blends with polyethylene terephthalate polymers complying with § 177.1630.

(a) *Identity.* For the purpose of this section, ethylene/1,3-phenylene oxyethylene isophthalate/terephthalate copolymer consists of the basic copolymer produced by the catalytic polycondensation of isophthalic acid and terephthalic acid with ethylene glycol and 1,3-bis(2-hydroxyethoxy)benzene such that the finished resin contains between 42 and 48 mole-percent of isophthalic moieties, between 2 and 8 mole-percent of terephthalic moieties, and not more than 10 mole-percent of 1,3-bis(2-hydroxyethoxy)benzene moieties.

(b) *Specifications*—(1) *Density.* Ethylene/1,3-phenylene oxyethylene isophthalate/terephthalate copolymer identified in paragraph (a) of this section has a density of 1.33±0.02 grams per cubic centimeter measured by ASTM Method D 1505-85 (Reapproved 1990), “Standard Test Method for Density of Plastics by the Density-Gradient Technique,” which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from the American Society for Testing and Materials, 100 Barr Harbor Dr., West Conshohocken, Philadelphia, PA 19428-2959, or may be examined at the Food and Drug Administration's Main Library, 10903 New Hampshire Ave., Bldg. 2, Third Floor, Silver Spring, MD 20993, 301-796-2039, and at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: *http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.*

(2) *Softening point.* Ethylene/1,3-phenylene oxyethylene isophthalate/terephthalate copolymer identified in paragraph (a) of this section has a softening point of 63±5 °C as measured by ASTM Method D 1525-87, “Standard Test Method for VICAT Softening Temperature of Plastics,” which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. The availability of this material is provided in paragraph (b)(1) of this section.

(c) *Optional adjuvant substances.* Ethylene/1,3-phenylene oxyethylene isophthalate/terephthalate copolymer, identified in paragraph (a) of this section, may contain optional adjuvant substances required in their production. The optional adjuvants may include substances used in accordance with § 174.5 of this chapter.

(d) *Limitations.* Copolymer blends described above shall not exceed 30 percent by weight of ethylene/1,3-phenylene oxyethylene isophthalate/terephthalate copolymer. The finished blend may be used in contact with food only under conditions of use C through G, as described in table 2 of § 176.170(c) of this chapter, except that with food identified as Type III, IV-A, V, VII-A, and IX in § 176.170(c), table 1, the copolymer may be used under condition of use C at temperatures not to exceed 160 °F (71 °C).

[57 FR 43399, Sept. 21, 1992, as amended at 59 FR 62318, Dec. 5, 1994; 61 FR 14481, Apr. 2, 1996; 62 FR 34628, June 27, 1997; 81 FR 5593, Feb. 3, 2016]