[Code of Federal Regulations]
[Title 21, Volume 3]
[Revised as of January 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR177.1655]
[Page 316-317]
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 317]]
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]
Back to Top
© 2007 Betterchem Corp.
|
