21 CFR 177.1555 : Food And Drugs (§ 1.1 To Parts 1403-1499) — (§ 170.3 To Parts 191-199) — Food And Drug Administration, Department Of Health And Human Services (Continued) (Parts 170 To 199) (§ 170.3 To Parts 191-199) — Food For Human Consumption (Continued) (§ 170.3 To Parts 191-199) — Indirect Food Additives: Polymers (Subpart A To § 177.2910) — Substances For Use As Basic Components Of Single And Repeated Use Food Contact Surfaces (§ 177.1010 To § 177.2000) — 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) of this chapter.