GrokFood Home
Loading

177.1655 Polysulfone resins.

Home > Regulations > Indirect food additives: Polymers > 177.1655 Polysulfone 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: 21CFR177.1655]

[Page 315-316]
 
                        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 B_Substances for Use as Basic Components of Single and Repeated 
                        Use Food Contact Surfaces
 
Sec.  177.1655  Polysulfone resins.

    Polysulfone resins identified in paragraph (a) of this section 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) For the purpose of this section, polysulfone resins are:
    (1) Poly(oxy-p-phenylenesulfonyl-p-phenyleneoxy-p-
phenyleneisopropylidene-p-phenylene) resins (CAS Reg. No. 25154-01-2) 
consisting of basic resins produced when the disodium salt of 4,4'-
isopropylidenediphenol is made to react with 4,4'-dichlorodiphenyl 
sulfone in such a way that the finished resins have a minimum number 
average molecular weight of 15,000, as determined by osmotic pressure in 
monochlorobenzene; or
    (2) 1,1'-Sulfonylbis[4-chlorobenzene] polymer with 4,4'-(1-
methylethylidene)bis[phenol] (minimum 92 percent) and 4,4'-
sulfonylbis[phenol] (maximum 8 percent) (CAS Reg. No. 88285-91-0) 
produced when a mixture of 4,4'-isopropylidenediphenol (minimum 92 
percent) and 4,4'-sulfonylbis[phenol] (maximum 8 percent) is made to 
react with 4,4'-dichlorodiphenyl sulfone in such a way that the finished 
resin has a minimum number average molecular weight of 26,000, as 
determined by osmotic pressure in dimethylformamide.
    (b) The basic polysulfone resins identified in paragraph (a) of this 
section may contain optional adjuvant substances required in the 
production of such basic resins. The optional adjuvant substances 
required in the production of the basic polysulfone resins may include 
substances described in Sec.  174.5(d) of this chapter and the 
following:

------------------------------------------------------------------------
          List of substances                       Limitations
------------------------------------------------------------------------
Dimethyl sulfoxide....................  Not to exceed 50 parts per
                                         million as residual solvent in
                                         finished basic resin in
                                         paragraph (a)(1) of this
                                         section.
Monochlorobenzene.....................  Not to exceed 500 parts per
                                         million as residual solvent in
                                         finished basic resin in
                                         paragraph (a)(1) of this
                                         section.
N-methyl-2-pyrrolidone................  Not to exceed 0.01 percent (100
                                         parts per million) as residual
                                         solvent in finished basic resin
                                         in paragraph (a)(2) of this
                                         section.
------------------------------------------------------------------------

    (c) Polysulfone resins, when extracted at reflux temperatures for 6 
hours with the solvents--distilled water, 50 percent (by volume) ethyl 
alcohol in distilled water, 3 percent acetic acid in distilled water, 
and n-heptane, yield total extractives in each extracting solvent not to 
exceed 0.0078 milligram per square centimeter (0.05 milligram per square 
inch) of resin surface. Note: In testing the finished polysulfone 
resins, use a separate resin test sample for each required extracting 
solvent.
    (d) Polysulfone resins intended for repeated use in contact with 
food may be used under conditions of use A through

[[Page 316]]

H in table 2 of Sec.  176.170(c) of this chapter. The resins intended 
for single-service food-contact use may be used only under condition of 
use H described in table 2 of Sec.  176.170(c) of this chapter.

[51 FR 882, Jan. 9, 1986; 51 FR 4165, Feb. 3, 1986; 61 FR 29475, June 
11, 1996]





Additives that reference this regulation:


Source: U.S. Code of Federal Regulations - CFR Title 21, Part 177, Section 1655


Home | About | Search