[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: |