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177.1520 Olefin polymers.

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[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: 21CFR177.1520]

[Page 283-298]
 
                        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.  177.1520  Olefin polymers.

    The olefin polymers listed in paragraph (a) of this section may be 
safely used as articles or components of articles intended for use in 
contact with food, subject to the provisions of this section.
    (a) For the purpose of this section, olefin polymers are basic 
polymers manufactured as described in this paragraph, so as to meet the 
specifications prescribed in paragraph (c) of this section, when tested 
by the methods described in paragraph (d) of this section.
    (1)(i) Polypropylene consists of basic polymers manufactured by the 
catalytic polymerization of propylene.
    (ii) Propylene homopolymer consists of basic polymers manufactured 
by the catalytic polymerization of propylene with a metallocene 
catalyst.
    (2)(i) Polyethylene consists of basic polymers manufactured by the 
catalytic polymerization of ethylene.
    (ii) Fumaric acid-grafted polyethylene (CAS Reg. No. 26877-81-6) 
consists of basic polymers manufactured by the catalytic polymerization 
of ethylene followed by reaction with fumaric acid in the absence of 
free radical initiators. Such polymers shall contain grafted fumaric 
acid at levels not to exceed 2 percent by weight of the finished 
polymer.
    (3) Olefin basic copolymers consist of basic copolymers manufactured 
by the catalytic copolymerization of:
    (i) Two or more of the 1-alkenes having 2 to 8 carbon atoms. Such 
olefin basic copolymers contain not less than 96 weight-percent of 
polymer units derived from ethylene and/or propylene, except that:
    (a)(1) Olefin basic copolymers manufactured by the catalytic 
copolymerization of ethylene and hexene-1 or ethylene and octene-1 shall 
contain not less than 90 weight-percent of polymer units derived from 
ethylene;
    (2) Olefin basic copolymers manufactured by the catalytic 
copolymerization of ethylene and hexene-1 shall contain not less than 80 
but not more than 90 weight percent of polymer units derived from 
ethylene.
    (3) Olefin basic copolymers manufactured by the catalytic 
copolymerization of ethylene and pentene-1 shall contain not less than 
90 weight-percent of polymer units derived from ethylene.
    (4) Olefin basic copolymers manufactured by the catalytic 
polymerization of ethylene and octene-1 shall contain not less than 50 
weight-percent of polymer units derived from ethylene.

[[Page 284]]

    (b) Olefin basic copolymers manufactured by the catalytic 
copolymerization of ethylene and 4-methylpentene-1 shall contain not 
less than 89 weight-percent of polymer units derived from ethylene;
    (c)(1) Olefin basic copolymers manufactured by the catalytic 
copolymerization of two or more of the monomers ethylene, propylene, 
butene-1, 2-methylpropene-1, and 2,4,4-trimethylpentene-1 shall contain 
not less than 85 weight-percent of polymer units derived from ethylene 
and/or propylene;
    (2) Olefin basic copolymers manufactured by the catalytic 
copolymerization of propylene and butene-1 shall contain greater than 15 
but not greater than 35 weight percent of polymer units derived from 
butene-1 with the remainder being propylene.
    (d) Olefin basic terpolymers manufactured by the catalytic 
copolymerization of ethylene, hexene-1, and either propylene or butene-
1, shall contain not less than 85 weight percent polymer units derived 
from ethylene.
    (e) Olefin basic copolymers manufactured by the catalytic 
polymerization of ethylene and octene-1, or ethylene, octene-1, and 
either hexene-1, butene-1, propylene, or 4-methylpentene-1 shall contain 
not less than 80 weight percent of polymer units derived from ethylene.
    (ii) 4-Methylpentene-1 and 1-alkenes having from 6 to 18 carbon 
atoms. Such olefin basic copolymers shall contain not less than 95 molar 
percent of polymer units derived from 4-methylpentene-1, except that 
copolymers manufactured with 1-alkenes having from 12 to 18 carbon atoms 
shall contain not less than 97 molar percent of polymer units derived 
from 4-methylpentene-1; or
    (iii) Ethylene and propylene that may contain as modifiers not more 
than 5 weight-percent of total polymer units derived by copolymerization 
with one or more of the following monomers:

5-Ethylidine-2-norbornene.
5-Methylene-2-norbornene.

    (iv) Ethylene and propylene that may contain as a modifier not more 
than 4.5 weight percent of total polymer units derived by 
copolymerization with 1,4-hexadiene.
    (v) Ethylene and butene-1 copolymers (CAS Reg. No. 25087-34-7) that 
shall contain not less than 80 weight percent of polymer units derived 
from ethylene.
    (vi) Olefin basic copolymers (CAS Reg. No. 61615-63-2) manufactured 
by the catalytic copolymerization of ethylene and propylene with 1,4-
hexadiene, followed by reaction with fumaric acid in the absence of free 
radical initiators. Such polymers shall contain not more than 4.5 
percent of polymer units deriving from 1,4-hexadiene by weight of total 
polymer prior to reaction with fumaric acid and not more than 2.2 
percent of grafted fumaric acid by weight of the finished polymer.
    (vii) Ethylene and 2-norbornene (CAS Reg. No. 26007-43-2) copolymers 
that shall contain not less than 30 and not more than 70 mole percent of 
polymer units derived from 2-norbornene.
    (4) Poly(methylpentene) consists of basic polymers manufactured by 
the catalytic polymerization of 4-methylpentene-1.
    (5) Polyethylene graft copolymers consist of polyethylene complying 
with item 2.2 of paragraph (c) of this section which subsequently has 
3a,4,7,7a-tetrahydromethyl-4,7-methanoisobenzofuran-1,3-dione grafted 
onto it at a level not to exceed 1.7 percent by weight of the finished 
copolymer.
    (6) Ethylene-maleic anhydride copolymers (CAS Reg. No. 9006-26-2) 
containing no more than 2 percent by weight of copolymer units derived 
from maleic anhydride.
    (b) The basic olefin polymers identified in paragraph (a) of this 
section may contain optional adjuvant substances required in the 
production of such basic olefin polymers. The optional adjuvant 
substances required in the production of the basic olefin polymers or 
finished food-contact articles may include substances permitted for such 
use by applicable regulations in parts 170 through 189 of this chapter, 
substances generally recognized as safe in food and food packaging, 
substances used in accordance with a prior sanction or approval, and the 
following:

[[Page 285]]



------------------------------------------------------------------------
               Substance                           Limitations
------------------------------------------------------------------------
Aromatic petroleum hydrocarbon resin,    For use only as an adjuvant at
 hydrogenated (CAS Reg. No. 88526-47-     levels not to exceed 25
 0), produced by the catalytic            percent by weight in blends
 polymerization of aromatic-substituted   with polypropylene complying
 olefins from distillates of cracked      with paragraph (c), item 1.1
 petroleum stocks with a boiling point    of this section. The finished
 no greater than 220 [deg]C (428          polymer may be used in contact
 [deg]F), and the subsequent catalytic    with food Types I, II, IV-B,
 hydrogenation of the resulting           VI-A through VI-C, VII-B, and
 aromatic petroleum hydrocarbon resin,    VIII identified in table 1 of
 having a minimum softening point of      Sec.   176.170(c) of this
 110 [deg]C (230 [deg]F), as determined   chapter and under conditions
 by ASTM Method E 28-67 (Reapproved       of use B through H described
 1982), ``Standard Test Method for        in table 2 of Sec.
 Softening Point by Ring-and-Ball         176.170(c) of this chapter;
 Apparatus,'' and a minimum aniline       and with food Types III, IV-A,
 point of 107 [deg]C (225 [deg]F), as     V, VII-A, and IX identified in
 determined by ASTM Method D 611-82,      table 1 of Sec.   176.170(c)
 ``Standard Test Methods for Aniline      of this chapter and under
 Point and Mixed Aniline Point of         conditions of use D through G
 Petroleum Products and Hydrocarbon       described in table 2 of Sec.
 Solvents,'' both of which are            176.170(c) of this chapter.
 incorporated by reference in
 accordance with 5 U.S.C. 552(a) and 1
 CFR part 51. Copies are available from
 the American Society for Testing and
 Materials, 100 Barr Harbor Dr., West
 Conshohocken, Philadelphia, PA 19428-
 2959, or from the Center for Food
 Safety and Applied Nutrition (HFS-
 200), Food and Drug Administration,
 5100 Paint Branch Pkwy., College Park,
 MD 20740, or may be examined 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..
Colorants used in accordance with Sec.
  178.3297 of this chapter.
2,5-Dimethyl-2,5-di(tert-                For use as an initiator in the
 butylperoxy)hexane (CAS Reg. No. 78-63-  production of propylene
 7).                                      homopolymer complying with
                                          Sec.   177.1520(c), item 1.1
                                          and olefin copolymers
                                          complying with Sec.
                                          177.1520(c), items 3.1 and 3.2
                                          and containing not less than
                                          75 weight percent of polymer
                                          units derived from propylene,
                                          provided that the maximum
                                          concentration of tert-butyl
                                          alcohol in the polymer does
                                          not exceed 100 parts per
                                          million, as determined by a
                                          method titled ``Determination
                                          of tert-Butyl Alcohol in
                                          Polypropylene,'' which is
                                          incorporated by reference.
                                          Copies are available from the
                                          Center for Food Safety and
                                          Applied Nutrition (HFS-200),
                                          Food and Drug Administration,
                                          5100 Paint Branch Pkwy.,
                                          College Park, MD 20740, or
                                          available for inspection 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.
Methyl methacrylate/butyl acrylate-      For use only at levels not to
 grafted polypropylene copolymer          exceed 6 percent by weight of
 containing methyl methacrylate/butyl     olefin polymers complying with
 acrylate-grafted polypropylene (CAS      paragraph (c) of this section,
 Reg. No. 121510-09-6), methyl            items 1.1, 3.1a, 3.2a, and
 methacrylate/butyl acrylate copolymer    3.2b, where the copolymers
 (CAS Reg. No. 25852-37-3), methyl        complying with items 3.1a,
 methacrylate homopolymer (CAS Reg. No.   3.2a, and 3.2b contain not
 9011-14-7), and polypropylene (CAS       less than 85 weight-percent of
 Reg. No. 9003-07-0), resulting from      polymer units derived from
 the reaction of a mixture of methyl      propylene.
 methacrylate and butyl acrylate with
 polypropylene. The finished product
 contains no more than 55 percent by
 weight of polymer units derived from
 methyl methacrylate and butyl acrylate
 as determined by a method entitled,
 ``Determination of the Total Acrylic
 in PP-MMA/BA Polymers,'' which is
 incorporated by reference in
 accordance with 5 U.S.C. 552(a) and 1
 CFR part 51. Copies are available from
 the Office of Premarket Approval,
 Center for Food Safety and Applied
 Nutrition (HFS-200), Food and Drug
 Administration, 5100 Paint Branch
 Pkwy., College Park, MD 20740, or may
 be examined at the Center for Food
 Safety and Applied Nutrition's
 Library, 5100 Paint Branch Pkwy.,
 College Park, MD 20740, 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..

[[Page 286]]


Petroleum hydrocarbon resins             For use only as an adjuvant at
 (cyclopentadiene-type), hydrogenated     levels not to exceed 30
 (CAS Reg. No. 68132-00-3) produced by    percent by weight in blends
 the thermal polymerization of            with: (1) Polypropylene
 dicyclopentadiene and cyclodiene         complying with paragraph (c),
 codimers (consisting of a mixture of     item 1.1 of this section, or
 cyclopentadiene, methyl                  (2) a copolymer of propylene
 cyclopentadiene, and C4-C5 acyclic       and ethylene containing not
 dienes), followed by hydrogenation and   less than 94 weight percent
 having a ring-and-ball softening point   propylene and complying with
 of 119 [deg]C minimum as determined by   paragraph (c), item 3.2 of
 ASTM Method E 28-67 (Reapproved 1982),   this section. The average
 ``Standard Test Method for Softening     thickness of the food-contact
 Point by Ring-and-Ball Apparatus,''      film is not to exceed 0.1
 and a minimum viscosity of 3,000         millimeter (0.004 inch). The
 centipoise, measured at 160 [deg]C, as   finished polymer may be used
 determined by ASTM Method D 3236-88,     in contact with (1) Food types
 ``Standard Test Method for Apparent      I, II, IV-B, VI-A, VI-B, VII-
 Viscosity of Hot Melt Adhesives and      B, and VIII identified in
 Coating Materials,'' both of which are   table 1 of Sec.   176.170(c)
 incorporated by reference in             of this chapter and under
 accordance with 5 U.S.C. 552(a) and 1    conditions of use C through G
 CFR part 51. Copies are available from   described in table 2 of Sec.
 the American Society for Testing and     176.170(c) of this chapter;
 Materials, 100 Barr Harbor Dr., West     and (2) food types III, IV-A,
 Conshohocken, Philadelphia, PA 19428-    V, VI-C, VII-A, and IX
 2959, or from the Center For Food        identified in table 1 of Sec.
 Safety and Applied Nutrition (HFS-        176.170(c) of this chapter
 200), Food and Drug Administration,      and under conditions of use D
 5100 Paint Branch Pkwy., College Park,   through G described in table 2
 MD 20740, or may be examined at the      of Sec.   176.170(c) of this
 National Archives and Records            chapter.
 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..
Polymethylsilsesquioxane (CAS Reg. No.   For use only as a surface
 68554-70-1).                             lubricant or anti-blocking
                                          agent in films.
Poly(vinylidene fluoride) homopolymer    For use only as a processing
 (CAS Reg. No. 24937-79-9), having a      aid in the production of
 melt viscosity of 6 to 37 kilopoise at   olefin polymers complying with
 a shear rate of 100-1 seconds at 232     paragraph (c) of this section
 [deg]C as determined by ASTM Method D    at levels not to exceed 1.0
 3835-79 (Reapproved 1983), ``Standard    percent by weight of the
 Test Method for Rheological Properties   polymer. The finished polymers
 of Thermoplastics with a Capillary       may be used only under the
 Rheometer'' using a capillary of 15:1    conditions described in Sec.
 L/D, which is incorporated by            176.170(c) of this chapter,
 reference in accordance with 5 U.S.C.    table 2, under conditions of
 552(a) and 1 CFR part 51. Copies are     use B though H.
 available from the Center for Food
 Safety and Applied Nutrition (HFS-
 200), Food and Drug Administration,
 5100 Paint Branch Pkwy., College Park,
 MD 20740, or may be examined 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..
Polyoxyethylene-grafted                  For use as an extrusion aid in
 polydimethylsiloxane (CAS Reg. No.       the production of extruded
 68937-54-2).                             olefin polymers that comply
                                          with Sec.   177.1520(c) at
                                          levels not to exceed 0.3
                                          percent by weight of the
                                          polymer. The finished polymer
                                          is used in contact with foods
                                          under conditions of use B
                                          through H described in table 2
                                          of Sec.   176.170 of this
                                          chapter.
Triisopropanolamine (CAS Reg. No. 122-   For use as a Zeigler-Natta-type
 20-3).                                   catalyst deactivator and
                                          antioxidant in the production
                                          of olefin polymers complying
                                          with Sec.   177.1520(c), items
                                          2.1, 2.2, and 2.3, and having
                                          a minimum density of 0.94
                                          grams per cubic centimeter,
                                          and copolymers complying with
                                          Sec.   177.1520(c), items 3.1
                                          and 3.2, for use in contact
                                          with all foods under the
                                          following conditions of use:
                                          (a) films with a maximum
                                          thickness of 0.102 millimeter
                                          (0.004 inch) may be used under
                                          conditions A through H defined
                                          in table 2 of Sec.
                                          176.170(c) of this chapter;
                                          and (b) articles with
                                          thickness greater than 0.102
                                          millimeter (0.004 inch) may be
                                          used under conditions C
                                          through G defined in table 2
                                          of Sec.   176.170(c) of this
                                          chapter.
Trimethylpyridine and dimethylpyridine   For use only as an adjuvant
 mixture having percent by weight         substance in the production of
 composition as follows: 2,4,6-           propylene homopolymers
 trimethylpyridine (CAS Reg. No. 108-75-  complying with items 1.1, 1.2,
 8), not less than 60 percent; 2,3,6-     and 1.3, and propylene
 trimethylpyridine (CAS Reg. No. 1462-    copolymers complying with
 84-6), not more than 27 percent; 3,5-    items 3.1, and 3.2 of
 dimethylpyridine (CAS Reg. No. 591-22-   paragraph (c) of this section
 0), not more than 12 percent; and        provided that the adjuvant is
 other dimethylpyridines, not more than   used at a level not to exceed
 6 percent.                               20 parts per million by weight
                                          of the olefin polymers.

[[Page 287]]


Vinylidene fluoride-hexafluoropropene    For use only as an extrusion
 copolymer (CAS Reg. No. 9011-17-0)       aid in the production of
 having a fluorine content of 65 to 71    extruded olefin polymers at
 percent and a Mooney viscosity of at     levels not to exceed 0.2
 least 28, as determined by a method      percent by weight of the
 entitled ``Mooney Viscosity,'' which     polymer. The finished polymers
 is incorporated by reference in          may be used only under the
 accordance with 5 U.S.C. 552(a).         conditions described in Sec.
 Copies are available from the Center     176.170(c) of this chapter,
 for Food Safety and Applied Nutrition    table 2, under conditions of
 (HFS-200), Food and Drug                 use B through H.
 Administration, 5100 Paint Branch
 Pkwy., College Park, MD 20740, or may
 be examined 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..
Vinylidene fluoride-hexafluoropropene    For use only as a processing
 copolymer (CAS Reg. No. 9011-17-0),      aid in the production of
 having a vinylidene fluoride content     olefin polymers complying with
 of not less than 87 percent but less     paragraph (c) of this section
 than 100 percent by weight and a melt    at levels not to exceed 1.0
 viscosity of 12 to 27 kilopoise at a     percent by weight of the
 shear rate of 100-1 seconds at 232       polymer. The finished polymers
 [deg]C as determined by ASTM Method D    may be used only under the
 3835-79 (Reapproved 1983), ``Standard    conditions described in Sec.
 Test Method for Rheological Properties   176.170(c) of this chapter,
 of Thermoplastics with a Capillary       table 2, under conditions of
 Rheometer'' using a capillary of 15:1    use B though H.
 L/D, which is incorporated by
 reference in accordance with 5 U.S.C.
 552(a) and 1 CFR part 51. Copies are
 available from the Center for Food
 Safety and Applied Nutrition (HFS-
 200), Food and Drug Administration,
 5100 Paint Branch Pkwy., College Park,
 MD 20740, or may be examined 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..
------------------------------------------------------------------------

    (c) Specifications:

----------------------------------------------------------------------------------------------------------------
                                                                                 Maximum
                                                                               extractable      Maximum soluble
                                                                                fraction           fraction
                                                        Melting Point (MP)    (expressed as      (expressed as
                                                        or softening point     percent by      percent by weight
           Olefin polymers                 Density         (SP) (Degrees      weight of the     of polymer) in
                                                           Centigrade)-      polymer) in N-        xylene at
                                                                                hexane at          specified
                                                                                specified        temperatures
                                                                              temperatures
----------------------------------------------------------------------------------------------------------------
  1.1a. Polypropylene described in    0.880-0.913       MP: 160[deg]-180    6.4 pct at        9.8 pct at 25
   paragraph (a)(1)(i) of this                           [deg]C.             reflux            [deg]C
   section                                                                   temperature
  1.1b. Propylene homopolymer         0.880-0.913-      MP: 150[deg]-180    6.4 pct at        9.8 pct at 25
   described in paragraph (a)(1)(ii)                     [deg]C.             reflux            [deg]C
   of this section                                                           temperature
1.2. Polypropylene, noncrystalline;   0.80-0.88
 for use only to plasticize
 polyethylene described under items
 2.1 and 2.2 of this table, provided
 that such plasticized polymers meet
 the maximum extractable fraction
 and maximum soluble fraction
 specifications prescribed for such
 basic polyethylene
1.3. Polypropylene, noncrystalline,   0.80-0.88         SP:115[deg]-138
 for use only: To plasticize                             [deg]C.
 polypropylene described by item 1.1
 of this table, provided that such
 plasticized polymers meet the
 maximum extractable fraction and
 maximum soluble fraction
 specifications prescribed for such
 basic polypropylene, and further
 provided that such plasticized
 polypropylene contacts food only of
 the types identified in Sec.
 176.170(c) of this chapter, table
 1, under Types I, II, IV-B, VI-B,
 VII-B, and VIII; and for use at
 levels not to exceed 50 pct by
 weight of any mixture employed as a
 food-contact coating provided such
 coatings contact food only of the
 types identified in Sec.
 176.170(c) of this chapter, table
 1, under Types I, II, IV-B, VI-B,
 VII-B, and VIII
2.1. Polyethylene for use in          0.85-1.00         ..................  5.5 pct at 50     11.3 pct at 25
 articles that contact food except                                           [deg]C            [deg]C
 for articles used for packing or
 holding food during cooking

[[Page 288]]


2.2. Polyethylene for use in          0.85-1.00         ..................  2.6 pct at 50      Do.
 articles used for packing or                                                [deg]C
 holding food during cooking
2.3. Polyethylene for use only as     0.85-1.00         ..................  53 pct at 50      75 pct at 25
 component of food-contact coatings                                          [deg]C            [deg]C
 at levels up to and including 50
 percent by weight of any mixture
 employed as a food-contact coating
2.4. Olefin polymers described in
 paragraph (a)(2)(ii) of this
 section, having a melt flow index
 not to exceed 17 grams/per 10
 minutes as determined by the method
 described in paragraph (d)(7) of
 this section, for use in blends
 with other polymers at levels not
 to exceed 20 percent by weight of
 total polymer, subject to the
 limitation that when contacting
 food of types III, IV-A, V, VI-C,
 VII-A, and IX identified in Sec.
 176.170(c) of this chapter, Table
 1, the polymers shall be used only
 under conditions of use C, D, E, F,
 and G, described in Sec.
 176.170(c) of this chapter, Table
 2.
3.1a. Olefin copolymers described in  0.85-1.00         ..................  5.5 pct at 50     30 pct at 25
 paragraph (a)(3)(i) of this section                                         [deg]C            [deg]C
 for use in articles that contact
 food except for articles used for
 packing or holding food during
 cooking; except olefin copolymers
 described in paragraph
 (a)(3)(i)(a)(3) of this section and
 listed in item 3.1c of this table
 and olefin copolymers described in
 paragraph (a)(3)(i)(e) of this
 section and listed in item 3.1b of
 this table
3.1b. Olefin copolymers described in  0.9-1.00          ..................   Do                Do.
 paragraph (a)(3)(i)(e) of this
 section for use in contact with
 food only under conditions of use
 D, E, F, G, and H described in Sec.
   176.170(c) of this chapter, table
 2
3.1c. Olefin copolymers described in  Not less than
 paragraph (a)(3)(i)(a)(3) of this     0.92
 section for use in contact with
 food only under conditions of use
 B, C, D, E, F, G, and H described
 in Sec.   176.170(c) of this
 chapter, table 2; except that such
 copolymers when used in contact
 with food of the types identified
 in Sec.   176.170(c), table 1,
 under types III, IVA, V, VIIA, and
 IX, shall be used only under
 conditions of use D, E, F, and G
 described in Sec.   176.170(c) of
 this chapter, table 2

[[Page 289]]


3.2a. Olefin copolymers described in  0.85-1.00         ..................  2.6 pct at 50      Do.
 paragraph (a)(3)(i) of this section                                         [deg]C
 for use in articles used for
 packing or holding food during
 cooking; except olefin copolymers
 described in paragraph
 (a)(3)(i)(c)(2) of this section and
 listed in item 3.2b of this table;
 except that olefin copolymers
 containing 89 to 95 percent
 ethylene with the remainder being 4-
 methyl-pentene-1 contacting food
 Types III, IVA, V, VIIA, and IX
 identified in Sec.   176.170(c) of
 this chapter, table 1, shall not
 exceed 0.051 millimeter (mm) (0.002
 inch (in)) in thickness when used
 under conditions of use A and shall
 not exceed 0.102 mm (0.004 in) in
 thickness when used under
 conditions of use B, C, D, E, and H
 described in Sec.   176.170(c) of
 this chapter, table 2.
 Additionally, olefin copolymers
 described in (a)(3)(i)(a)(2) of
 this section may be used only under
 conditions of use B, C, D, E, F, G,
 and H described in Sec.
 176.170(c) of this chapter, table
 2, in contact with all food types
 identified in Sec.   176.170(c) of
 this chapter, table 1
3.2b. Olefin copolymers described in   Do.
 paragraph (a)(3)(i)(c)(2) of this
 section have a melt flow index no
 greater than 10 grams per 10
 minutes as determined by the method
 described in paragraph (d)(7) of
 this section, and the thickness of
 the finished polymer contacting
 food shall not exceed 0.025 mm
 (0.001 in). Additionally, optional
 adjuvants permitted for use in
 olefin copolymers complying with
 item 3.2a of this table may be used
 in the production of this copolymer
3.2c. Olefin copolymers described in   0.85-0.92
 paragraph (a)(3)(i)(a)(4) of this
 section have a melt flow index no
 greater than 50 grams per 10
 minutes as determined by the method
 described in paragraph (d)(7) of
 this section. Articles manufactured
 using these polymers may be used
 with all types of food under
 conditions of use C through H as
 described in table 2 of Sec.
 176.170(c) of this chapter
 3.3a. Olefin copolymers described
 in paragraph (a)(3)(ii) of this
 section and manufactured with 1-
 alkenes having from 6 to 10 carbon
 atoms
 3.3b. Olefin copolymers described
 in paragraph (a)(3)(ii) of this
 section, provided that such olefin
 polymers have a melt temperature of
 220 [deg]C to 250 [deg]C (428
 [deg]F to 482 [deg]F) as determined
 by the method described in
 paragraph (d)(8) of this section
 and minimum intrinsic viscosity of
 1.0 as determined in paragraph
 (d)(9) of this section.

[[Page 290]]


3.4. Olefin copolymers, primarily     0.85-0.90
 non-crystalline, described in par.
 (a)(3) (iii) of this section
 provided that such olefin polymers
 have a minimum viscosity average
 molecular weight of 120,000 as
 determined by the method described
 in par. (d)(5) of this section and
 a minimum Mooney viscosity of 35 as
 determined by the method described
 in par. (d)(6) of this section, and
 further provided that such olefin
 copolymers contact food only of the
 types identified in Sec.
 176.170(c) of this chapter, table
 1, under Types I, II, III, IV-B,
 VI, VII, VIII, and IX
3.5. Olefin copolymers, primarily     0.85-0.90
 non-crystalline, described in
 paragraph (a)(3)(iv) of this
 section, provided that such olefin
 polymers have a minimum viscosity
 average molecular weight of 95,600
 as determined by the method
 described in paragraph (d)(5) of
 this section, and further provided
 that such olefin polymers are used
 only in blends with olefin polymers
 described under items 1.1, 2.1, and
 2.2 of this table at a maximum
 level of 25 pct by weight, and
 provided that such olefin
 copolymers contact food only of the
 types identified in Sec.   176.170
 (c) of this chapter, table 1, under
 Types I, II, IV-B, VI, VII-B, and
 VIII at temperatures not exceeding
 190 [deg]F
3.6. Olefin copolymers described in   Not less than
 paragraph (a)(3)(v) of this section   0.88
 for use in blends with olefin
 polymer resins have a melt flow
 index no greater than 5 grams/10
 minutes as determined by the method
 described in paragraph (d)(7) of
 this section and the thickness of
 the finished blends shall not
 exceed 0.1 millimeter (0.004 inch).
 The ethylene/butene-1 copolymer may
 be used subject to the following
 conditions: (1) For use at a level
 not to exceed 20 weight percent in
 polypropylene as described under
 item 1.1 of this table. (2) For use
 at a level not to exceed 40 weight
 percent in polyethylene as
 described under items 2.1 and 2.2
 of this table. (3) For use at a
 level not to exceed 40 weight
 percent in olefin copolymers as
 described under items 3.1 and 3.2
 of this table

[[Page 291]]


3.7. Ethylene/propylene copolymers,   Not less than
 meeting the identity described in     0.86
 paragraph (a)(3)(i) of this
 section, containing not less than
 80 mole-percent of polymer units
 derived from ethylene and having a
 minimum viscosity average molecular
 weight of 95,000 as determined by
 the method described in paragraph
 (d)(5) of this section, and a
 minimum Mooney viscosity of 13 as
 determined by the method described
 in paragraph (d)(6) of this
 section. Ethylene/propylene
 copolymers described in this item
 3.7 are to be used only in blends
 with other olefin polymers
 complying with this section, at
 levels not to exceed 30 percent by
 weight of the total polymer blend,
 and in contact with food only of
 types identified in Sec.
 176.170(c) of this chapter, Table
 1, under Types I, II, III, IV-B,
 VI, VII, VIII, and IX.
 Additionally, optional adjuvants
 permitted for use in olefin
 copolymers complying with item 3.4
 of this table may be used in the
 production of this copolymer
3.8. Olefin polymers described in
 paragraph (a)(3)(vi) of this
 section, having a melt flow index
 not to exceed 9.2 grams per 10
 minutes as determined by the method
 described in paragraph (d)(7) of
 this section, for use in blends
 with other polymers at levels not
 to exceed 8 percent by weight of
 total polymer, subject to the
 limitation that when contacting
 food of types III, IV-A, V, VI-C,
 VII-A, and IX, identified in Sec.
 176.170(c) of this chapter, Table
 1, the polymers shall be used only
 under conditions of use C, D, E, F,
 and G, described in Sec.
 176.170(c) of this chapter, Table
 2.
3.9. Olefin copolymers described in   Not less than
 paragraph (a)(3)(vii) of this         1.0
 section may only be used in contact
 with dry foods, Type VIII, as
 identified in Sec.   176.170(c) of
 this chapter, Table 1
4. Poly(methylpentene)                0.82-0.85         MP: 235[deg]-250    6.6 pct at        7.5 pct at 25
                                                         [deg]C.             reflux            [deg]C
                                                                             temperature
5. Polyethylene copolymer described   Not less than     ..................  0.45 pct at 15    1.8 pct at 25
 in paragraph (a)(5) of this section   0.94                                  [deg]C            [deg]C
 and having a melt index not to
 exceed 2, for use, either alone or
 in blends with other olefin
 polymers, subject to the limitation
 that when contacting foods of types
 III, IV-A, V, VI-C, VII-A, VIII,
 and IX identified in Sec.
 176.170(c) of this chapter, table
 1, the thickness of the film (in
 mils) containing the polyethylene
 graft copolymer times the
 concentration of the polyethylene
 graft copolymer shall not exceed a
 value of 2
6. Ethylene-maleic anhydride          0.92 or greater   ..................  1.36 pct at 50    2.28 pct at 25
 copolymers described in paragraph                                           [deg]C            [deg]C
 (a)(6) of this section for use as
 the adhesive component in
 multilaminate structures, or as the
 sealant layer in flexible
 packaging, in contact with food at
 temperatures not exceeding 49
 [deg]C (120 [deg]F)
----------------------------------------------------------------------------------------------------------------

    (d) The analytical methods for determining whether olefin polymers 
conform to the specifications prescribed in this section are as follows, 
and are applicable to the basic polymer in film form not exceeding 4 
mils in thickness.

[[Page 292]]

The film to be tested shall be cut into approximately 1-inch squares by 
any convenient method that avoids contamination by dust, dirt, or grease 
(Note: Do not touch samples with bare fingers--use forceps to hold or 
transfer samples).
    (1) Density. Density shall be determined by ASTM method D1505-68 
(Reapproved 1979), ``Standard Test Method for Density of Plastics by the 
Density-Gradient Technique,'' 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 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.
    (2) Melting point or softening point--(i) Melting point. The melting 
point shall be determined by ASTM method D2117-82, ``Standard Test 
Method for Melting Point of Semicrystalline Polymers by the Hot Stage 
Microscopy Method,'' which is incorporated by reference. The 
availability of this incorporation by reference is given in paragraph 
(d)(1) of this section.
    (ii) Softening point. The softening point shall be determined by 
ASTM method E28-67 (Reapproved 1982), ``Standard Test Method for 
Softening Point by Ring-and-Ball Apparatus,'' which is incorporated by 
reference. The availability of this incorporation by reference is given 
in paragraph (d)(1) of this section.
    (3) Maximum extractable fraction in n-hexane--(i) Olefin copolymers 
described in paragraph (a)(3)(ii) of this section, polypropylene, and 
poly(methylpentene). A sample is refluxed in the solvent for 2 hours and 
filtered at the boiling point. The filtrate is evaporated and the total 
residue weighed as a measure of the solvent extractable fraction.
    (a) Apparatus. (1) Erlenmeyer flasks, 250-milliliter, with ground 
joint.
    (2) Condensers, Allihn, 400-millimeter jacket, with ground joint.
    (3) Funnels, ribbed 75-millimeter diameter, stem cut to 40 
millimeters.
    (4) Funnels, Buchner type, with coarse-porosity fritted disc, 60-
millimeter diameter.
    (5) Bell jar for vacuum filtration into beaker.
    (b) Reagent. n-Hexane, commercial grade, specific gravity 0.663-
0.667 (20 [deg]C/20 [deg]C), boiling range 66 [deg]C-69 [deg]C, or 
equivalent.
    (c) Procedure. Weigh 1 gram of sample accurately and place in a 250-
milliliter Erlenmeyer flask containing two or three boiling stones. Add 
100 milliliters of solvent, attach the flask to the condenser (use no 
grease), and reflux the mixture for 2 hours. Remove the flask from the 
heat, disconnect the condenser, and filter rapidly, while still hot, 
through a small wad of glass wool packed in a short-stem funnel into a 
tared 150-millimeter beaker. Rinse the flask and filter with two 10-
milliliter portions of the hot solvent, and add the rinsings to the 
filtrate. Evaporate the filtrate on a stream bath with the aid of a 
stream of nitrogen. Dry the residue in a vacuum oven at 110 [deg]C for 2 
hours, cool in a desiccator, and weigh to the nearest 0.0001 gram. 
Determine the blank on 120 milliliters of solvent evaporated in a tared 
150-milliliter beaker. Correct the sample residue for this blank if 
significant. Calculation:
[GRAPHIC] [TIFF OMITTED] TR01JA93.398

    (ii) Olefin copolymers described in paragraph (a)(3)(i) of this 
section and polyethylene. A preweighed sample is extracted at 50 [deg]C 
for 2 hours and filtered. The filtrate is evaporated and the total 
residue weighed as a measure of the solvent extractable fraction. 
Alternatively, the sample is reweighed after the extraction period to 
give a measure of the solvent extractable fraction. The

[[Page 293]]

maximum n-hexane-extractable fraction may be determined by the methods 
set forth in paragraphs (d)(3)(ii)(a) through (d)(3)(ii)(i) of this 
section.
    (a) Extraction apparatus. Two-liter, straight-walled, Pyrex (or 
equivalent) resin kettles, fitted with three-hole ground-glass covers 
are most convenient for this purpose. The cover is fitted with a 
thermometer, a gas-tight stirrer driven by an air motor or explosion-
proof electric motor, and a reflux condenser. The kettle is fitted with 
an electric heating mantle of appropriate size and shape, which is 
controlled by a variable-voltage transformer.
    (b) Evaporating apparatus. Rapid evaporation of large volumes of 
solvent requires special precautions to prevent contamination by dust. 
This is facilitated by a special ``gas'' cover consisting of an inverted 
flat Pyrex crystallizing dish of an appropriate size (190 millimeters x 
100 millimeters) to fit a 1-liter beaker. Through the center of the dish 
are sealed an inlet tube for preheated, oxygen-free nitrogen, and an 
outlet tube located 1 inch off center. Nitrogen is fed from the supply 
source through a coil of \1/4\-inch stainless steel tubing immersed in 
the same steam bath used to supply heat for solvent evaporation. All 
connections are made with flexible tetrafluoroethylene tubing.
    (c) Reagents--(1) n-Hexane. Spec tro grade n-hexane.
    (2) Nitrogen. High-purity dry nitrogen containing less than 10 parts 
per million of oxygen.
    (d) Procedure. Transfer 2.5 grams (accurately weighed to nearest 
0.001 gram) of the polymer to the resin kettle. Add 1 liter of solvent 
and clamp top in position. Start water flowing through jacket of the 
reflux condenser and apply air pressure to the stirring motor to produce 
vigorous agitation. Turn on heating jacket with transformer set at a 
predetermined voltage to bring the temperature of the contents to 50 
[deg]C within 20-25 minutes. As the thermometer reading approaches 45 
[deg]C-47 [deg]C, reduce the voltage to the predetermined setting that 
will just maintain the temperature at 50 [deg]C. Do not overshoot the 
prescribed temperature. Should this occur discard the test and start 
afresh. Exactly 2 hours after the solvent temperature has reached 50 
[deg]C, disconnect the heater, remove the resin kettle from the heating 
jacket, and decant the solvent, while still warm, through a coarse 
filter paper placed on top of a fritted-glass funnel, collecting the 
filtrate in a tared, glass-stoppered Erlenmeyer flask of 1-liter 
capacity. Determine the weight of the filtrate recovered to the nearest 
gram. Recovery should be at least 90 percent of the original solvent. 
Losses due to evaporation during heating and filtering have been found 
not to exceed 10 percent. Transfer about half of the solvent filtrate to 
a 1-liter beaker placed on an opening in the steam bath and immediately 
cover with the special ``gas'' cover, the inlet tube of which has been 
attached with flexible tetrafluoroethylene tubing to a source of high-
purity nitrogen in series with a stainless steel heating coil immersed 
directly in the body of the steam bath. Maintain a positive flow of warm 
nitrogen gas throughout the evaporation of the solvent, adding the 
remainder of the filtrate from the Erlenmeyer flask as the evaporation 
proceeds. When the volume of the solvent has been reduced to about 50 
milliliters, transfer the concentrated liquid to a previously tared 
weighing dish of suitable size. Wash the beaker twice with 20-30 
milliliter portions of warm solvent, adding the washings to the weighing 
dish while continuing to evaporate the remainder of the solvent under 
the gas cover with its flow of warm nitrogen directed toward the center 
of the dish. In the event that an insoluble residue that cannot be 
removed with warm solvent remains in the beaker, it may be necessary to 
heat with a small amount of a higher boiling solvent such as benzene or 
toluene, transferring these washings to the weighing dish before final 
evaporation to dryness. Transfer the weighing dish with its residue to a 
vacuum desiccator, and allow it to remain overnight (at least 12 hours), 
after which the net weight of the dry residue is determined to the 
nearest 0.0001 gram. Correct the result for any solvent blank equivalent 
to the nonvolatile matter determined to be contained in the amount of 
solvents used in the test.

[[Page 294]]

    (e) Extraction apparatus for alternate method. Two-liter extraction 
vessel, such as a resin kettle or round bottom flask, fitted with an 
Allihn condenser (size C), a 45/50 male joint with a Teflon sleeve, and 
a Teflon coated stir bar. Water bath maintained at 49.5 [deg]C 0.5 [deg]C containing a submersible magnetic stirrer 
motor with power supply. Other suitable means of maintaining temperature 
control, such as electric heating mantles, may be used provided that the 
temperature range can be strictly maintained.
    (f) Sample basket (Optional). A perforated stainless steel 
cylindrical basket that is approximately 1.5 inches in diameter, 1.6 
inches high, and has perforations of 0.125 inches in diameter for 33 
holes/in\2\, or 40 percent open area. The basket should pass freely 
through the 45/50 female joint of the extraction flask. A No. 6-32 
stainless steel eye-bolt is attached to the lid for positioning the 
basket in the extraction vessel. The positioning rod, approximately 18 
inches long and made from 1/16 inch outside diameter 316 stainless steel 
welding rod or equivalent and hooked at both ends, is used to position 
the basket in the extraction apparatus.
    (g) Vacuum oven. Capable of maintaining 80 [deg]C 5 [deg]C and a minimum of 635 millimeters of mercury 
pressure.
    (h) Reagents. n-Hexane, reagent or spectrograde, aromatic free (less 
than 1 milligram per liter), minimum 85 percent n-hexane. This reagent 
may be reused until it contains a maximum of 1.5 grams polyolefin 
extractables or has been used for 12 determinations.
    (i) Procedure. Assemble the extraction vessel, condenser, and 
magnetic stir bar. Add n-hexane (1 liter) to the extraction vessel and 
clamp the assembly into a water bath set at 49.5 [deg]C 0.5 [deg]C. Start the water flowing through the jacket 
of the reflux condenser. Adjust the air flow through the stirring motor 
to give a smooth and uniform stir rate. Allow the n-hexane to preheat 
for 1 hour to bring the temperature to 49.5 [deg]C0.5 [deg]C. Temperature is a critical factor in this 
analysis and it must not vary more than 1 [deg]C. If the temperature 
exceeds these limits, the test must be discontinued and restarted. 
Blown, compression molded, or extrusion cast films can be tested. 
Ideally, the film should be prepared by the same process as will be used 
with the production resin. Using gloves and metal tweezers to avoid 
sample contamination, cut about 2.7 grams of the prepared film (4 mils 
or less in thickness) into about 1-inch squares using clean sharp 
scissors. Proceed with Option 1 or 2.
    Option 1. Using tweezers and noting the number of film pieces, 
transfer 2.5 grams (accurately weighed to 0.1 milligram) of polymer to 
the extraction vessel. Extract the film sample for 2 hours. Allow the 
vessel to cool and filter the contents through a fritted porcelain 
funnel. Wash the film pieces with fresh n-hexane, aspirate to dryness, 
and transfer, using tweezers, to a beaker. Recount the film pieces to 
verify that none were lost during the transfer. Place the beaker in the 
vacuum oven for 2 hours at 80 [deg]C 5 [deg]C. 
After 2 hours, remove and place in a desiccator to cool to room 
temperature (about 1 hour). After cooling, reweigh the film pieces to 
the nearest 0.1 milligram. Calculate the percent hexane-extractables 
content from the weight loss of the original sample. Multiply the result 
by 0.935 and compare with extraction limits in paragraph (c) of this 
section. Repeat the above procedure for successive samples.
    Option 2. Transfer 2.50.05 grams of the 
prepared 1-inch film sections into a tared sample basket and accurately 
weigh to the nearest 0.1 milligram. Carefully raise the condenser until 
the hook on the positioning rod is above the neck of the 2-liter 
extraction vessel. The basket should be totally below the level of n-
hexane solvent. Extract the sample resin film for 2 hours and then raise 
the basket above the solvent level to drain momentarily. Remove the 
basket and rinse the contents by immersing several times in fresh n-
hexane. Allow the basket to dry between rinsings. Remove the excess 
solvent by briefly blowing the basket with a stream of nitrogen or dry 
air. Place the basket in the vacuum oven for 2 hours at 80 [deg]C 5 [deg]C. After 2 hours, remove and place in a 
desiccator to cool to room temperature (about 1 hour). After cooling, 
reweigh the basket to the nearest 0.1 milligram. Calculate

[[Page 295]]

the percent hexane extractables content from the weight loss of the 
original sample. Multiply the result by 0.935 and compare with 
extraction limits in paragraph (c) of this section. Repeat the above 
procedure for successive samples. The same solvent charge should remain 
clear and can be used for at least 12 determinations. Applications of 
solvent reuse should be confirmed for each resin type before use.
    (4) Maximum soluble fraction in xylene--(i) Olefin copolymers 
described in paragraph (a)(3)(ii) of this section, polypropylene, and 
poly(methylpen-tene). A sample is dissolved completely in xylene by 
heating and stirring in a bottle with little free space. The solution is 
allowed to cool without stirring, whereupon the insoluble portion 
precipitates and is filtered off; the total solids content of the 
filtrate is then determined as a measure of the soluble fraction.
    (a) Apparatus. (1) Pyrex (or equivalent) reagent bottle, 125-
milliliter, glass-stoppered.
    (2) Heating mantle of size for 150-milliliter beaker (or suitable 
aluminum block to fit the 125-milliter bottle described in paragraph 
(d)(4)(i)(a)(1) of this section.
    (3) Magnetic stirrer for use under the heating mantle (combination 
magnetic stirrer and hotplate may be used if aluminum block is used in 
place of heating mantle).
    (4) Variable-voltage transformer, 7.5 amperes.
    (5) Tetrafluoroethylene-resin-coated stirring bar, 1-inch long.
    (6) Constant temperature water bath maintained at 25 [deg]C0.5 [deg]C.
    (7) Aluminum dishes, 18 millimeters x 60 millimeters, disposable.
    (8) Funnel, Buchner type, with coarse-porosity fritted disc, 30-60 
millimeter diameter.
    (b) Reagent. Xylene with antioxidant. Dissolve 0.020 gram of phenyl-
[beta]- naphthylamine in 1 liter of industrial grade xylene having 
specific gravity 0.856-0.867 (20 [deg]C/20 [deg]C) and boiling range 123 
[deg]C-160 [deg]C.
    (c) Procedure. Weigh 1 to 2 grams of sample to the nearest 0.001 
gram and place in a 125-milliliter Pyrex reagent bottle containing a 1-
inch long tetrafluoroethylene-resin-coated stirring bar. Add 100 
milliliters of solvent, set the stopper in lightly, and place the bottle 
in the heating mantle or aluminum block maintained at a temperature of 
120 [deg]C, and stir with a magnetic stirrer until the sample is 
completely dissolved. Remove the bottle from the heat and allow it to 
cool 1 hour in the air, without stirring. Then place the bottle in a 
water bath maintained at 25 [deg]C 0.5 [deg]C, and 
allow to stand 1 hour without stirring. Next, remove the bottle from the 
water bath, shake, and pour part of the contents into the coarse-
porosity fritted-glass funnel. Apply suction, and draw 30-40 milliliters 
of filtrate through, adding more slurry to the funnel, and catching the 
filtrate in a large test tube. (If the slurry is hard to filter, add 10 
grams of diatomaceous earth filter aid to the bottle and shake 
vigorously just prior to the filtration.) Pipet a suitable aliquot 
(preferably 20 milliliters) of the filtrate into a tared aluminum 
disposable dish. Place the dish on a steam bath covered with a fresh 
sheet of aluminum foil and invert a short-stemmed 4-inch funnel over the 
dish. Pass nitrogen (heated if desired) down through the funnel at a 
rate sufficient to just ripple the surface of the solvent. When the 
liquid has evaporated, place the dish in a vacuum oven at 140 [deg]C and 
less than 50 millimeters mercury pressure for 2 hours. Cool in a 
desiccator and weigh. (Note: If the residue value seems high, redry in 
the vacuum oven for one-half hour to ensure complete removal of all 
xylene solvent.) Calculation:
[GRAPHIC] [TIFF OMITTED] TR01JA93.399


[[Page 296]]


    (ii) Olefin copolymers described in paragraph (a)(3)(i) of this 
section and polyethylene. A sample is extracted in xylene at reflux 
temperature for 2 hours and filtered. The filtrate is evaporated and the 
total residue weighed as a measure of soluble fraction.
    (a) Apparatus--(1) Extraction apparatus. Two-liter, straight-walled 
Pyrex (or equivalent) resin kettles, fitted with ground-glass covers, 
are most convenient for this purpose. The cover is equipped with a 
thermometer and an efficient reflux condenser. The kettle is fitted with 
an electric heating mantle of appropriate size and shape which is 
controlled by a variable-voltage transformer.
    (2) Constant temperature water bath. It must be large enough to 
permit immersion of the extraction kettle and set to maintain 25 [deg]C 
0.1 [deg]C.
    (3) Evaporating apparatus. Gas cover consisting of a flat Pyrex 
crystallizing dish (190 millimeters x 100 millimeters) inverted to fit 
over a 1-liter beaker with 8-millimeter gas inlet tube sealed through 
center and an outlet tube 1 inch off center. The beaker with gas cover 
is inserted in an electric heating mantle equipped with a variable-
voltage transformer. The outlet tube is attached to an efficient 
condenser mounted on a receiving flask for solvent recovery and having 
an outlet for connection to an aspirator pump. The heating mantle (with 
the beaker) is mounted on a magnetic stirring device. An infrared heat 
lamp is mounted vertically 3-4 inches above the gas cover to prevent 
condensation of the solvent inside the cover. Make all connections with 
flexible tetrafluoroethylene tubing.
    (b) Reagents--(1) Xylene. American Chemical Society reagent grade 
that has been redistilled through a fractionating column to reduce the 
nonvolatile residue.
    (2) Nitrogen. High-purity dry nitrogen containing less than 10\4\ 
parts per million oxygen.
    (c) Procedure. Transfer 5 grams 0.001 gram of 
sample to the resin kettle, add 1,000 milliliters (840 grams) of xylene, 
and clamp top in position after inserting a piece of glass rod to 
prevent bumping during reflux. Start water flowing through the jacket of 
the reflux condenser and apply full voltage (115 volts) to the heating 
mantle. When the xylene starts to boil, reduce the voltage to a level 
just sufficient to maintain reflux. After refluxing for at least 2 
hours, disconnect the power source to the mantle, remove the kettle, and 
allow to cool in air until the temperature of the contents drops to 50 
[deg]C, after which the kettle may be rapidly cooled to 25 [deg]C-30 
[deg]C by immersing in a cold water bath. Transfer the kettle to a 
constant temperature bath set to maintain 25 [deg]C 0.1 [deg]C, and allow to equilibrate for a least 1 hour 
(may be left overnight if convenient). Break up any precipitated 
polymers that may have formed, and decant the xylene solution 
successively through a fast filter paper and then through a fritted-
glass filter into a tared 1-liter Erlenmeyer flask, collecting only the 
first 450 milliliters--500 milliliters of filtrate (any attempt to 
collect more of the xylene solution usually results in clogging the 
filter and risking losses). Reweigh the Erlenmeyer flask and calculate 
the weight of the filtrate obtained to the nearest 0.1 gram. Transfer 
the filtrate, quantitatively, from the Erlenmeyer flask to the 1-liter 
beaker, insert the beaker in its heating mantle, add a glass-coated 
magnetic stirring bar, and mount the gas cover in place, connecting the 
inlet tube to the nitrogen source and the outlet to the condenser of the 
receiving flask. Start a flow of nitrogen (2 to 3 liters per minute) 
into the gas cover and connect an aspirator to the receiver using a 
free-flow rate equivalent to 6-7 liters of air per minute. With the 
infrared lamp on, adjust the voltage to the heating mantle to give a 
distillation rate of 12-13 milliliters per minute when the magnetic 
stirrer is revolving just fast enough to promote good boiling. When the 
volume of solvent in the beaker has been reduced to 30-50 milliliters, 
transfer the concentrated extractive to a suitable weighing dish that 
has been previously tared (dry). Rinse the beaker twice with 10-20 
milliliter portions of fresh xylene, adding the rinsings to the weighing 
dish. Evaporate the remainder of the xylene on an electric hotplate set 
at low heat under the gas cover with a stream of nitrogen directed 
toward the center of the dish.

[[Page 297]]

Avoid any charring of the residue. Transfer the weighing dish to a 
vacuum desiccator at room temperature and allow to remain under reduced 
pressure for at least 12 hours (overnight), after which determine the 
net weight of the residue to the nearest 0.0001 gram. Correct the result 
for nonvolatile solvent blank obtained by evaporating the equivalent 
amount of xylene under identical conditions. Calculate the weight of 
residue originally present in the total weight of solvent (840 grams), 
using the appropriate factor based on the weight of filtrate evaporated.
    (5) Viscosity average molecular weight olefin copolymers described 
in paragraphs (a)(3) (iii) and (iv) of this section. The viscosity 
average molecular weight shall be determined from the kinematic 
viscosity (using ASTM method D445-74, ``Test for Kinematic Viscosity of 
Transparent and Opaque Liquids'' (Revised 1974), which is incorporated 
by reference; copies are available from American Society for Testing and 
Materials (ASTM), 100 Barr Harbor Dr., West Conshohocken, Philadelphia, 
PA 19428-2959, or available for inspection 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.) of solutions of the copolymers in solvents and at 
temperatures as follows:
    (i) Olefin polymers described in paragraph (a)(3)(iii) of this 
section in decahydronaphthalene at 135 [deg]C.
    (ii) Olefin polymers described in paragraph (a)(3)(iv) of this 
section in tetrachloroethylene at 30 [deg]C.
    (6) Mooney viscosity--olefin copolymers described in paragraph 
(a)(3)(iii) of this section. Mooney viscosity is determined by ASTM 
method D1646-81, ``Standard Test Method for Rubber--Viscosity and 
Vulcanization Characteristics (Mooney Viscometer),'' which is 
incorporated by reference (the availability of this incorporation by 
reference is given in paragraph (d)(1) of this section), using the large 
rotor at a temperature of 100 [deg]C, except that a temperature of 127 
[deg]C shall be used for those copolymers whose Mooney viscosity cannot 
be determined at 100 [deg]C. The apparatus containing the sample is 
warmed for 1 minute, run for 8 minutes, and viscosity measurements are 
then made.
    (7) Melt flow index. The melt flow index of olefin polymers 
described below shall be determined by ASTM method D-1238-82, ``Standard 
Test Method for Flow Rates of Thermoplastics by Extrusion Plastometer,'' 
which is incorporated by reference in accordance with 5 U.S.C. 552(a). 
The availability of this incorporation by reference is given in 
paragraph (d)(1) of this section. The olefin polymers and test 
conditions and procedures are as follows:

------------------------------------------------------------------------
            List of polymers                  Conditions/procedures
------------------------------------------------------------------------
Olefin copolymers described in           Condition L, procedure A.
 paragraph (a)(3)(i)(c)(2) of this
 section.
Olefin copolymers described in           Condition E, procedure A.
 paragraph (a)(3)(v) of this section.
Olefin polymers described in paragraph   Condition E, procedure A.
 (a)(2)(ii) of this section.
Olefin polymers described in paragraph   Condition E, procedure A.
 (a)(3)(vi) of this section.
------------------------------------------------------------------------

    (8) Melting peak temperature. The melt temperature of the olefin 
polymers described in paragraph (a)(3)(ii) of this section shall be 
determined by ASTM method D 3418-82, ``Standard Test Method for 
Transition Temperatures of Polymers by Thermal Analysis,'' which is 
incorporated by reference in accordance with 5 U.S.C. 552(a). The 
availability of this incorporation by reference is given in paragraph 
(d)(1) of this section.
    (9) Intrinsic viscosity. The intrinsic viscosity of the olefin 
polymers described in paragraph (a)(3)(ii) of this section shall be 
determined by ASTM method D 1601-78, ``Standard Test Method for Dilute 
Solution Viscosity of Ethylene Polymers,'' which is incorporated by 
reference in accordance with 5 U.S.C. 552(a). The availability of this 
incorporation by reference is given in paragraph (d)(1) of this section.
    (e) Olefin copolymers described in paragraph (a)(3) (i) of this 
section and polyethylene, alone or in combination, may be subjected to 
irradiation bombardment from a source not to exceed 2.3 million volts 
intensity to cause molecular crosslinking of the polymers to impart 
desired properties, such as increased strength and increased ability to 
shrink when exposed to heat.

[[Page 298]]

    (f) The olefin polymers 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.
    (g) The provisions of this section are not applicable to olefin 
polymers identified in Sec.  175.105(c) (5) of this chapter and used in 
food-packaging adhesives complying with Sec.  175.105 of this chapter.

[42 FR 14572, Mar. 15, 1977]

    Editorial Note: For Federal Register citations affecting Sec.  
177.1520, see the List of CFR Sections Affected, which appears in the 
Finding Aids section of the printed volume and on GPO Access.





Additives that reference this regulation:


Source: U.S. Code of Federal Regulations - CFR Title 21, Part 177, Section 1520


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