[Code of Federal Regulations]
[Title 21, Volume 3]
[Revised as of April 1, 2001]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR177.2460]
[Page 326-328]
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. 177.2460 Poly(2,6-dimethyl-1,4-phenylene) oxide resins.
The poly(2,6-dimethyl-1,4-phenylene) oxide resins identified in
paragraph (a) of this section may be used as an article or as a
component of an article intended for use in contact with food subject to
the provisions of this section.
[[Page 327]]
(a) Identity. For the purposes of this section, poly(2,6-dimethyl-
1,4-phenylene) oxide resins consist of basic resins produced by the
oxidative coupling of 2,6-xylenol such that the finished basic resins
meet the specifications and extractives limitations prescribed in
paragraph (c) of this section.
(b) Optional adjuvant substances. The basic poly(2,6-dimethyl-1,4-
phenylene) oxide 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 poly(2,6-dimethyl-1,4-phenylene) oxide resins
may include substances permitted for such use by regulations in parts
170 through 189 of this chapter, substances generally recognized as safe
in food, substances used in accordance with a prior sanction or
approval, and the following:
------------------------------------------------------------------------
Limitations (expressed as
List of substances percent by weight of
finished basic resin)
------------------------------------------------------------------------
Diethylamine.............................. Not to exceed 0.16 percent
as residual catalyst.
Methyl alcohol............................ Not to exceed 0.02 percent
as residual solvent.
Toluene................................... Not to exceed 0.2 percent as
residual solvent.
------------------------------------------------------------------------
(c) Specifications and extractives limitations. The poly(2,6-
dimethyl-1,4-phenylene) oxide basic resins meet the following:
(1) Specifications. Intrinsic viscosity is not less than 0.30
deciliter per gram as determined by ASTM method D1243-79, ``Standard
Test Method for Dilute Solution Viscosity of Vinyl Chloride Polymers,''
which is incorporated by reference, modified as follows. Copies of the
incorporation by reference may be obtained from the American Society for
Testing Materials, 1916 Race St., Philadelphia, PA 19103, or may be
examined at the Office of the Federal Register, 800 North Capitol
Street, NW., suite 700, Washington, DC 20408.
(i) Solvent: Chloroform, reagent grade containing 0.01 percent tert-
butylcatechol.
(ii) Resin sample: Powdered resin obtained from production prior to
molding or extrusion.
(iii) Viscometer: Cannno-Ubbelohde series 25 dilution viscometer (or
equivalent).
(iv) Calculation: The calculation method used is that described in
appendix X.1.3 (ASTM method D1243-79, cited and incorporated by
reference in paragraph (c)(1) of this section) with the reduced
viscosity determined for three concentration levels (0.4, 0.2, and 0.1
gram per deciliter) and extrapolated to zero concentration for
intrinisic viscosity. The following formula is used for determining
reduced viscosity:
[GRAPHIC] [TIFF OMITTED] TR01JA93.406
where:
t=Solution efflux time.
to=Solvent efflux time.
c=Concentration of solution in terms of grams per deciliter.
(2) Extractives limitations. Total resin extracted not to exceed
0.02 weight-percent when extracted with n-heptane at 160 deg.F for 2
hours as determined using 200 milliliters of reagent grade n-heptane
which has been freshly distilled before use and 25 grams of poly (2,-6-
dimethyl-1,4-phenylene) oxide resin. The resin as tested is in pellet
form having a particle size such that 100 percent of the pellets will
pass through a U.S. Standard Sieve No. 6 and 100 percent of the pellets
will be held on a U.S. Standard Sieve No. 10.
(d) Other limitations. The poly(2,6-dimethyl-1,4-phenylene) oxide
resins identified in and complying with this section, when used as
components of the food-contact surface of any article that is the
subject of a regulation in parts 174, 175, 176, 177, 178 and Sec. 179.45
of this chapter, shall comply with any specifications and limitations
prescribed by such regulation for the article in the finished form in
which it is to contact food.
(e) Uses. The poly(2,6-dimethyl-1,4-phenylene) oxide resins
identified in and complying with the limitations in this section may be
used as articles or components of articles intended for repeated food-
contact use or as articles or components of articles intended for
single-service food-contact use only under the conditions described in
[[Page 328]]
Sec. 176.170(c) of this chapter, table 2, conditions of use H.
[42 FR 14572, Mar. 15, 1977, as amended at 49 FR 10111, Mar. 19, 1984;
63 FR 8852, Feb. 23, 1998]