---
kind: "section"
citation: "21 C.F.R. § 177.1555"
title: "21"
number: "177.1555"
heading: "Polyarylate resins."
url: "https://uscodex.org/cfr/21/177.1555"
---

# §177.1555. Polyarylate resins.


Polyarylate resins (CAS Reg. No. 51706-10-6) may be safely used as articles or components of articles intended for use in contact with food in accordance with the following prescribed conditions:

- (a) **Identity.** Polyarylate resins (1, 3-benzenedicarboxylic acid, diphenyl ester, polymer with diphenyl 1,4-benzenedicarboxylate and 4-4′-(1-methylethylidine) bis(phenol)) are formed by melt polycondensation of bisphenol-A with diphenylisophthalate and diphenylterephthalate.
- (b) **Specifications.**
  - (1) The finished copolymers shall contain from 70 to 80 weight percent of polymer units derived from diphenylisophthalate and 20 to 30 weight percent of polymer units derived from diphenylterephthalate.
  - (2) Polyarylate resins shall have a minimum weight average molecular weight of 20,000.
  - (3) Polyarylate resins may be identified by their characteristic infrared spectra.
- (c) **Extractive limitations.** The finished polyarylate resins in sheet form at least 0.5 millimeter (0.020 inch) thick, when extracted with water at 121 °C (250 °F) for 2 hours, shall yield total nonvolatile extractives not to exceed 2.33 micrograms per square centimeter (15 micrograms per square inch) of the exposed resin surface.
- (d) **Limitations.** Polyarylate resin articles may be used in contact with all foods except beverages containing more than 8 volume percent ethanol under conditions of use A through H, described in table 2 of [§ 176.170(c)](/cfr/21/176.170.md?p=c) of this chapter.

## Notes

### Amendments

[52 FR 35540, Sept. 22, 1987]

### Authority

Authority: 21 U.S.C. 321, 342, 348, 379e.

### Source

Source: 42 FR 14572, Mar. 15, 1977, unless otherwise noted.

### Amendments

[52 FR 35540, Sept. 22, 1987]