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177.1580 Polycarbonate resins
Polycarbonate resins may be safely used as articles or components of articles intended for use in producing, manufacturing, packing, processing, preparing, treating, packaging, transporting, or holding food, in accordance with the following prescribed conditions:
（a Polycarbonate resins are polyesters produced by:
? The condensation of 4,4-iso-propylidenediphenol and carbonyl chloride to which may have been added certain optional adjuvant substances required in the production of the resins; or by
? The reaction of molten 4,4-iso-propylidenediphenol with molten diphenyl carbonate in the presence of the disodium salt of 4,4-isopro-pylidenediphenol.
? The condensation of 4,4-isopro- pylidenediphenol, carbonyl chloride, and 0.5 percent weight maximum of a 2,a 6-bis ?-hydroxy-m- tolyl mesitol to which may have been added certain optional adjuvant substances required in the production of branched polycarbonate resins.
（b The optional adjuvant substances required in the production of resins produced by the methods described in paragraph （a）（1 and ? of this section may include substances generally recognized as safe in food, substances used in accordance with a prior sanction or approval, and the following:
| List of substances | Limitations |
| p-tert-Butylphenol | |
| Chloroform | |
| p-Cumylphenol (CAS Reg. No. 599-64-4) | For use only as a chain terminator at a level not to exceed 5 percent by weight of the resin. |
| Ethylene dichloride | |
| Heptane | |
| Methylene chloride | |
| Monochlorobenzene | Not to exceed 500 p.p.m. as residual solvent in finished resin. |
| Pentaerythritol tetrastearate (CAS Reg. No. 115-83-3) | For use only as a mold release agent, at a level not to exceed 0.5 percent by weight of the finished resin. |
| Phenol (CAS Reg. No. 108-95-2) | |
| Pyridine | |
| Toluene: (CAS Reg. No. 108-88-3) | Not to exceed 800 parts per million as residual solvent in finished resin. |
| Triethylamine |
（c Polycarbonate resins shall conform to the specification prescribed in paragraph （c）（1 of this section and shall meet the extractives limitations prescribed in paragraph （c）（2 of this section.
? Specification. Polycarbonate resins can be identified by their characteristic infrared spectrum.
? Extractives limitations. The polycarbonate resins to be tested shall be ground or cut into small particles that will pass through a U.S. standard sieve No. 6 and that will be held on a U.S. standard sieve No. 10.
（i Polycarbonate resins, when extracted with distilled water at reflux temperature for 6 hours, shall yield total extractives not to exceed 0.15 percent by weight of the resins.
（ii Polycarbonate resins, when extracted with 50 percent （by volume ethyl alcohol in distilled water at reflux temperature for 6 hours, shall yield total extractives not to exceed 0.15 percent by weight of the resins.
（iii Polycarbonate resins, when extracted with n- heptane at reflux temperature for 6 hours, shall yield total extractives not to exceed 0.15 percent by weight of the resins.
[42 FR 14572, Mar. 15, 1977, as amended at 46 FR 23227, Apr. 24, 1981; 49 FR 4372, Feb. 6, 1984; 50 FR 14096, Apr. 10, 1985; 53 FR 29656, Aug. 8, 1988; 59 FR 43731, Aug. 25, 1994]
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