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177.2440 Polyethersulfone resins.

Home > Regulations > Indirect food additives: Polymers > 177.2440 Polyethersulfone resins.



[Code of Federal Regulations]
[Title 21, Volume 3]
[Revised as of April 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR177.2440]

[Page 340-341]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                          SERVICES (CONTINUED)
 
PART 177_INDIRECT FOOD ADDITIVES: POLYMERS--Table of Contents
 
Subpart C_Substances for Use Only as Components of Articles Intended for 
                              Repeated Use
 
Sec.  177.2440  Polyethersulfone resins.

    Polyethersulfone resins identified in paragraph (a) of this section 
may be safely used as articles or components of articles intended for 
repeated use in contact with food in accordance with the following 
prescribed conditions:
    (a) For the purpose of this section, polyethersulfone resins are:
    (1) Poly(oxy-p-phenylenesulfonyl-p-phenylene) resins (CAS Reg. No. 
25667-42-9), which have a minimum number average molecular weight of 
16,000.
    (2) 1,1'-sulfonylbis[4-chlorobenzene] polymer with 4,4'-(1-methyl 
ethyl idene)bis[phenol] (maximum 8 percent) and 4,4'-sulfonylbis[phenol] 
(minimum 92 percent) (CAS Reg. No. 88285-91-0), which have a minimum 
number average molecular weight of 26,000.
    (3) In paragraphs (a)(1) and (a)(2) of this section, the minimum 
number average molecular weight is determined by reduced viscosity in 
dimethyl formamide in accordance with ASTM method D2857-70 (Reapproved 
1977), ``Standard Test Method for Dilute Solution Viscosity of 
Polymers,'' which is incorporated by reference. Copies may be obtained 
from the American Society for Testing Materials, 100 Barr Harbor Dr., 
West Conshohocken, Philadelphia, PA 19428-2959, or may be examined at 
the Division of Petition Control (HFS-215), Center for Food Safety and 
Applied Nutrition, 1110 Vermont Ave. NW., suite 1200, Washington, DC, or 
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.
    (b) The basic resins identified in paragraphs (a)(1) and (a)(2) of 
this section may contain optional adjuvant substances described in Sec.  
174.5(d) of this chapter and the following:

[[Page 341]]



------------------------------------------------------------------------
            List of substances                       Limitations
------------------------------------------------------------------------
Diphenylsulfone...........................  Not to exceed 0.2 percent as
                                             residual solvent in the
                                             finished basic resin
                                             described in paragraph
                                             (a)(1) of this section.
Dimethyl sulfoxide........................  Not to exceed 0.01 percent
                                             as residual solvent in the
                                             finished basic resin
                                             described in paragraph
                                             (a)(1) of this section.
N-methyl-2-pyrrolidone....................  Not to exceed 0.01 percent
                                             as residual solvent in the
                                             finished basic resin
                                             described in paragraph
                                             (a)(2) of this section.
------------------------------------------------------------------------

    (c) The finished food-contact article, when extracted at reflux 
temperatures for 2 hours with the following four solvents, yields net 
chloroform-soluble extractives in each extracting solvent not to exceed 
0.02 milligram per square inch of food-contact surface: distilled water, 
50 percent (by volume) ethyl alcohol in distilled water, 3 percent 
acetic acid in distilled water, and n-heptane. (Note: In testing the 
finished food-contact article, use a separate test sample for each 
required extracting solvent.)
    (d) In accordance with good manufacturing practice, finished food-
contact articles containing the polyethersulfone resins shall be 
thoroughly cleansed before their first use in contact with food.

[44 FR 34493, June 15, 1979, as amended at 47 FR 38885, Sept. 3, 1982; 
49 FR 10111, Mar. 19, 1984; 50 FR 47211, Nov. 15, 1985; 60 FR 48648, 
Sept. 20, 1995]





Additives that reference this regulation:


Source: U.S. Code of Federal Regulations - CFR Title 21, Part 177, Section 2440


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