Section

[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: 21CFR177.1500]

[Page 263-269]

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. 177.1500 Nylon resins.

The nylon resins listed in paragraph (a) of this section may be
safely used to produce articles intended for use in processing,
handling, and packaging food, subject to the provisions of this section:
(a) The nylon resins are manufactured as described in this paragraph
so as to meet the specifications prescribed in paragraph (b) of this
section when tested by the methods described in paragraph (c) of this
section.
(1) Nylon 66 resins are manufactured by the condensation of
hexamethylene-diamine and adipic acid.
(2) Nylon 610 resins are manufactured by the condensation of
hexamethylene-diamine and sebacic acid.
(3) Nylon 66/610 resins are manufactured by the condensation of
equal-weight mixtures of nylon 66 salts and nylon 610 salts.
(4) Nylon 6/66 resins manufactured by the condensation and
polymerization of Nylon 66 salts and epsilon-caprolactam.
(5) Nylon 11 resins are manufactured by the condensation of 11-
aminoundecanoic acid.
(6) Nylon 6 resins are manufactured by the polymerization of
epsilon-caprolactam.
(7) Nylon 66T resins are manufactured by the condensation of
hexamethyl-enediamine, adipic acid, and terephthalic acid such that
composition in terms of ingredients is 43.1^plus-minus0.2
weight percent hexamethyl-enediamine, 35.3^plus-minus1.2
weight percent adipic acid, and 21.6^plus-minus1.2 weight
percent terephthalic acid.
(8) Nylon 612 resins are manufactured by the condensation of
hexamethylenediamine and dodecanedioic acid.
(9) Nylon 12 resins are manufactured by the condensation of omega-
laurolactam.
(10)(i) Impact modified Nylon MXD-6 resins (CAS Reg. No. 59655-05-9)
manufactured by the condensation of adipic acid, 1,3-
benzenedimethanamine, and T3alpha-(3-aminopropyl)-omega-(3-amino-
propoxy)poly- oxyethylene under such conditions that the alpha-(3-amino-
propyl)-omega-(3-aminopropoxy) polyoxyethylene monomer content does not
exceed 7 percent by weight of the finished resin.
(ii) Nylon MXD-6 resins (CAS Reg. No. 25718-70-1) manufactured by
the condensation of adipic acid and 1,3-benzenedimethanamine.
(11) Nylon 12T resins are manufactured by the condensation of omega-
laurolactam (CAS Reg. No. 0947-04-6), isophthalic acid (CAS Reg. No.
0121-91-5), and bis(4-amino-3-methylcycl-ohexyl)methane (CAS Reg. No.
6864-37-5) such that the composition in terms of ingredients is
34.4^plus-minus1.5 weight percent omega-laurolactam,
26.8^plus-minus0.4 weight percent isophthalic acid, and
38.8^plus-minus0.5 weight percent bis(4-amino-3-
methylcyclohexyl)-methane.
(12) Nylon 6I/6T resins (CAS Reg. No. 25750-23-6) are manufactured
by the condensation of hexamethylenediamine, terephthalic acid, and
isophthalic acid such that 65 to 80 percent of the polymer units are
derived from hexamethylene isophthalamide.
(13)(i) Nylon 6/12 resins (CAS Reg. No. 25191-04-2) are manufactured
by the copolymerization of a 1 to 1 ratio by weight of epsilon-
caprolactam and omega-laurolactam.

[[Page 264]]

(ii) Nylon 6/12 resins (CAS Reg. No. 25191-04-2) are manufactured by
the copolymerization of a ratio of at least 80 weight percent of
epsilon-caprolactam and no more than 20 weight percent of omega-
laurolactam.
(14) Nylon 6/69 resins (CAS Reg. No. 51995-62-1) are manufactured by
the condensation of 49.5+0.5 weight percent epsilon-caprolactam,
19.4+0.2 weight percent hexamethylenediamine and 31.2+0.3 weight percent
azelaic acid.
(15) Nylon 46 resins (CAS Reg. No. 50327-77-0) are manufactured by
the condensation of 1,4-butanediamine and adipic acid.
(16) Nylon resins PA 6-3-T (CAS Registry No. 26246-77-5) are
manufactured by the condensation of 50 mol percent 1,4-
benzenedicarboxylic acid, dimethyl ester and 50 mol percent of an
equimolar mixture of 2,2,4-trimethyl-1,6-hexanediamine and 2,4,4-
trimethyl-1,6-hexanediamine.
(b) Specifications:

[[Page 265]]

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Maximum extractable fraction in selected solvents
Melting (expressed in percent by weight of resin)
point Solubility in Viscosity No. (mL/---------------------------------------------------
Nylon resins Specific gravity (degrees boiling 4.2N HC1 g) 95 percent
Fahrenheit) Water ethyl Ethyl Benzene
alcohol acetate
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Nylon 66 resins............. 1.14^plus-minus.0 475-495 Dissolves in 1 h. ................. 1.5 1.5 0.2 0.2
15
2. Nylon 610 resins............ 1.09^plus-minus.0 405-425 Insoluble after 1 ................. 1.0 2.0 1.0 1.0
15 h.
3.1 Nylon 66/610 resins........ 1.10^plus-minus.0 375-395 Dissolves in 1 h. ................. 1.5 2.0 1.0 1.0
15
4.1 Nylon 6/66 resins, epsilon- 1.13^plus-minus.0 440-460 ......do......... ................. 2.0 2.0 1.5 1.5
caprolactam monomer content 15
not to exceed 0.7 percent by
weight.
4.2 Nylon 6/66 resins with 1.14^plus-minus.0 380-425 ......do......... ................. 0.8 1.0 0.5 0.5
combined caprolactam content 15
greater than 60 percent and
residual epsilon-caprolactam
monomer content not to exceed
0.4 percent by weight. For use
only as specified in Sec.
177.1395 of this chapter (CAS
Reg. No. 24993-04-2).
5.1 Nylon 11 resins for use in 1.04^plus-minus.0 355-375 Insoluble after 1 ................. .30 .35 .25 .3
articles intended for 1-time 15 h.
use or repeated use in contact
with food.
5.2 Nylon 11 resins for use 1.04^plus-minus.0 355-375 ......do......... ................. .35 1.60 .35 .40
only: 15
a. In articles intended for
repeated use in contact with
food.
b. In side-seam cements for
articles intended for 1-time
use in contact with food and
which are in compliance with
Sec. 175.300 of this
chapter.
6.1 Nylon 6 resins............. 1.15^plus-minus.0 392-446 Dissolves in 1 h. ................. 1.0 2.0 1.0 1.0
15
6.2 Nylon 6 resins for use only 1.15^plus-minus.0 392-446 ......do......... ................. 1.5 2.0 1.0 1.0
in food-contact films having 15
an average thickness not to
exceed 0.001 in.
7. Nylon 66T resins for use 1.16^plus-minus.0 482-518 Insoluble after 1 ................. 1.0 1.0 .25 .25
only in food-contact films 15 h.
having an average thickness
not to exceed 0.001 in.
8. Nylon 612 resins for use 1.06^plus-minus.0 406-420 ......do......... ................. .50 1.50 .50 .50
only in articles intended for 15
repeated use in contact with
food at temperatures not to
exceed 212 deg.F.
9. Nylon 12 resins for use 1.01^plus-minus.0 335-355 ......do......... ................. 1.0 2.0 1.50 1.50
only:. 15
a. In food-contact films having ................
an average thickness not to
exceed 0.0016 inch intended
for use in contact with
nonalcoholic food under the
conditions of use A
(sterilization not to exceed
30 minutes at a temperature
not to exceed 250 deg.F), and
B through H of table 2 of Sec.
176.170(c) of this chapter,
except as provided in Sec.
177.1390(d)

[[Page 266]]

b. In coatings intended for
repeated use in contact with
all food types described in
table 1 of Sec. 176.170(c) of
this chapter, except those
containing more than 8 percent
alcohol, under conditions of
use B through H described in
table 2 of Sec. 176.170(c) of
this chapter.
10.1 Nylon MXD-6 and impact 1.21^plus-minus0. 437-491 Dissolves in 1h.. ................. 2.0 2.5 1.0 1.0
modified Nylon MXD-6 film 02
having an average thickness
not to exceed 40 microns
(0.0016 inch) for use in
processing, handling, and
packaging of food of types V
and IX listed in table 1 of
Sec. 176.170(c) of this
chapter under conditions of
use C, D, E, F, G, and H in
table 2 of Sec. 176.170(C) of
this chapter.
10.2 Impact modified Nylon MXD- 1.21^plus-minus0. 437-491 do............... ................. 2.0 2.5 1.0 1.0
6 resins for use as polymer 02
use as polymer modifiers in
Nylon 6 resin films complying
with paragraph (a)(6) of this
section, at levels not to
exceed 13 percent by weight of
films whose average thickness
will not exceed 15 microns
(0.6 mils). The finished film
is used for packaging,
transporting, or holding food,
excluding beverages containing
more than 8 percent alcohol
(by volume) at temperatures
not to exceed 49 deg.C (120
deg.F) (conditions of use E,
F, and G in table 2 of Sec.
176.170(c) of this chapter).
10.3 Nylon MXD-6 resins for use 1.22 455-470 Dissolves in 1 h. 1.0 1.5 0.2 0.2
only as nonfood-contact layers 0.02
of: (1) Multilayer films and
(2) rigid plastic containers
composed of polypropylene food-
contact and exterior layers,
as defined in Sec.
177.1520(c), item 1.1(a) and
1.1(b), of this chapter. The
finished food-contact
laminate, in the form in which
it contacts food, when
extracted with the food
simulating solvent or solvents
characterizing the conditions
of the intended use as
determined from Table 2 of
Sec. 176.170(c) of this
chapter, shall yield not more
than 0.5 micrograms of m-
xylylenediamine-adipic acid
cyclic monomer per square inch
of food-contact surface, when
the food simulating solvent is
analyzed by any appropriate,
properly validated method.
11. Nylon 12T resins for use in 1.06^plus-minus0. 290-310 Insoluble after 1 ................. 0.1 ........... 0.5 0.5
contact with all types of food 015 hour.
except those containing more
than 8 percent alcohol.

[[Page 267]]

12. Nylon 6I/6T resins for use 1.207^plus-minus0 N/A Insoluble after 1 ................. 0.2 1.0 0.1 0.1
in contact with all types of .1 hour.
food except alcoholic
beverages containing more than
8 percent alcohol.
13.1 Nylon 6/12 resins for use 1.06^plus-minus0. 260-285 Dissolves in 1 Greater than 140. 2.0 ........... 1.5 1.5
only in food-contact films 015 hour.
having an average thickness
not to exceed 51 microns
(0.002 inch). The finished
film is intended to contact
all foods except those
containing more than 8 percent
ethanol under conditions of
use B, C, D, E, F, G, and H
listed in table 2 of Sec.
176.170(c) of this chapter.
13.2 Nylon 6/12 resins with 1.10^plus-minus0. 380-400 Dissolves in 1 h. Greater than 160. 0.8 1.0 0.5 0.5
residual epsilon-caprolactam 15
not to exceed 0.5 percent by
weight and residual omega-
laurolactam not to exceed 0.1
percent by weight. For use
only as specified in Sec.
177.1395 of this chapter.
13.3 Nylon 6/12 resins with 1.13 400-420 Dissolves in 1 h. ............... 1.0 1.5 0.5 0.5
residual epsilon-caprolactam 0.15
not to exceed 0.8 percent by
weight and residual omega-
laurolactam not to exceed 0.1
percent by weight. For use
only as specified in Sec.
177.1390 of this chapter.
14. Nylon 6/69 resins for use 1.09^plus-minus0. 270-277 ................. >140 using the 3.0 ........... ........... ...........
only as specified in 21 CFR 02 method described
177.1395 of this chapter. in Sec.
177.1500(c)(5)(i
i) of this
chapter.
15. Nylon 46 resins for use 1.18^plus-minus0. 551-09592 Dissolves in 1 h. ................. 0.3 0.2 0.2 0.3
only in food-contact membrane 015
filters intended for repeated
use. The finished membrane
filter is intended to contact
beverages containing no more
than 13 percent alcohol, under
conditions of use E, F, and G
listed in table 2 of Sec.
176.170(c) of this chapter.
16. Nylon resins PA 6-3-T for 1.12^plus-minus0. NA Insoluble after 1 > 110............ 0.007 0.64 0.003 0
repeated-use (excluding 03 h.
bottles) in contact with food
of type VIA and VIB described
in table 1 of Sec. 176.170(c)
of this chapter under
conditions of use D through H
described in table 2 of Sec.
176.170(c) of this chapter
with a hot-fill temperature
limitation of 40 deg.C.
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[[Page 268]]

(c) Nylon modifier--(1) Identity. Copolyester-graft-acrylate
copolymer is the substance 1,4-benzenedicarboxylic acid, polymer with
1,4-butanediol, (E)-2-butenedioic acid, 1,2-ethanediol, ethyl 2-
propenoate, hexanedioic acid and 2-propenoic acid, graft (CAS Reg. No.
175419-23-5), and is derived from grafting of 25 weight percent of
acrylic polymer with 75 weight percent of copolyester. The copolyester
is polymerized terephthalic acid (55 mol%), adipic acid (40 mol%), and
fumaric acid (5 mol%) with ethylene glycol (40 mol%) and 1,4-butanediol
(60 mol%). The acrylic polymer is made from acrylic acid (70 mol%) and
ethyl acrylate (30 mol%).
(2) Specifications. The finished copolyester-graft-acrylate
copolymer shall meet the following specifications:
(i) Weight average molecular weight 15,000-35,000,
(ii) pH 7.2 to 8.2, and
(iii) Glass transition temperature -15 to -25 1/2C.
(3) Conditions of use. (i) Copolyester-graft acrylate copolymer
described in paragraph (c)(1) of this section is intended to improve the
adhesive qualities of film. It is limited for use as a modifier of Nylon
6 and Nylon 6 modified with Nylon MXD-6 at a level not to exceed 0.17
weight percent of the additive in the finished film.
(ii) The finished film is used for packaging, transporting, or
holding all types of foods under conditions of use B through H,
described in table 2 of Sec. 176.170(c) of this chapter, except that in
the case of Nylon 6 films modified with Nylon MXD-6 (complying with
Sec. 177.1500, item 10.2), the use complies with the conditions of use
specified in table 2.
(iii) Extractives. Food contact films described in paragraphs (c)(1)
of this section, when extracted with solvent or solvents prescribed for
the type of food and under conditions of time and temperature specified
for the intended use, shall yield total extractives not to exceed 0.5
milligram per inch squared of food-contact surface when tested by the
methods described in Sec. 176.170(d) of this chapter.
(iv) Optional adjuvant substances. The substances employed in the
production of Nylon modifiers listed in paragraph (c)(1) of this section
may include:
(A) Substances generally recognized as safe for use in food and food
packaging;
(B) Substances subject to prior sanction or approval for use in
Nylon resins and used in accordance with such sanctions or approval; and
(C) Optional substances required in the production of the additive
identified in this paragraph and other optional substances that may be
required to accomplish the intended physical or technical effect.
(d) Analytical methods--(1) Specific gravity. Specific gravity shall
be determined by weighing a 1-gram to 5-gram sample first in air and
then in freshly boiled distilled water at 23
deg.C^plus-minus2 deg.C.
(2) Melting point. The melting point shall be determined as follows:
Use a hot-stage apparatus. The use of crossed nicol prisms with a
microscope hot stage and reading of the thermometer when the
birefringence disappears increases the accuracy. If the crossed nicol
apparatus is not available, use the lowest temperature at which the
sample becomes transparent or the sharp edges or corners of the sample
become rounded as the melting point. In case of doubt as to the onset of
melting, the sample is prodded with a sharp instrument. If it sticks to
the heating block, it is considered to have melted. If the melting point
is low, dry the sample in an oven at 85 deg.C for 24 hours in a
nitrogen atmosphere then repeat the test.
(3) Solubility in boiling 4.2N HCl. The test shall be run on a
sample approximately the size of a \1/8\-inch cube in at least 25
milliliters of 4.2 normal hydrochloric acid.
(4) Maximum extractable fraction in selected solvents. The procedure
for determining the maximum extractable fraction of the nylon resins in
selected solvents is as follows:
(i) Film should be cut with ordinary scissors into pieces of a
convenient size such as \1/4\-inch squares, for the extraction tests
described in this section. The granules of nylon molding powders are in
the proper form for the extraction tests. Samples of fabricated articles
such as pipe, fittings, and other similar articles must be cut to
approximately

[[Page 269]]

the size of the molding powder. This can be done conveniently by using a
small-scale commercial plastics granulator and cutting the sample
through a screen having \1/4\-inch mesh. Fine particles should be
separated from the cut resin by screening through a 20-mesh screen. The
material retained on the screen is suitable for the extraction tests.
(ii) The organic solvents must be of American Chemical Society
analytical reagent grade; distilled water is used. Approximately 30
grams of the prepared sample is weighed to the nearest milligram. The
weighed resin is transferred to a 500-milliliter round-bottom flask
equipped with a reflux condenser. Approximately 300-milliliters of
solvent is added to the flask and the contents refluxed gently for 8
hours with a heating mantle. The solvent is then filtered off
immediately while still hot, using a Buchner funnel approximately 5
inches in diameter, a suction flask, and a hardened filter paper
(Whatman No. 50 or equivalent). The paper is wet with the solvent and a
slight suction applied just before starting the filtration. The resin is
washed twice with approximately 100-milliliter portions of solvent and
the combined filtrate and washings are reduced to approximately 25
milliliters by evaporation at reduced pressure (50 millimeters to 100
millimeters of mercury, absolute), heating as necessary. The contents of
the flask are transferred to an evaporation dish (which has been held in
a vacuum desiccator over anhydrous calcium sulfate until constant weight
has been attained) and carefully evaporated to dryness. The weight of
the solid residue is determined by difference after holding in a vacuum
desiccator over anhydrous calcium sulfate until constant weight has been
attained. The percent of solids extracted is calculated by dividing the
weight of the solid residue by the weight of the sample and multiplying
by 100.
(5) Viscosity number (VN). (i) The viscosity number (VN) for Nylon
6/12 resin in a 96 percent sulfuric acid solution (5 milligrams resin
per milliliter) shall be determined at 25 deg.C (77 deg.F) by method
ISO 307-1984(E), ``Plastics-Polyamides-Determination of Viscosity
Number,'' which is incorporated by reference. Copies are available from
the Center for Food Safety and Applied Nutrition (HFS-200), Food and
Drug Administration, 200 C St. SW., Washington, DC 20204, or available
for inspection at the Office of the Federal Register, 800 North Capitol
Street, NW., suite 700, Washington, DC 20408.
(ii) The viscosity number (VN) for Nylon 6/69 and Nylon PA-6-3-T
resins in a 99 percent cresol solution (5 milligrams resin per
milliliter) shall be determined at 25 deg.C (77 deg.F) by method ISO
307-1984(E), ``Plastics-Polyamides-Determination of Viscosity Number,''
which is incorporated by reference. The availability of this
incorporation by reference is given in paragraph (d)(5)(i) of this
section.

[42 FR 14572, Mar. 15, 1977]

Editorial Note: ForFederal Register citations affecting
Sec. 177.1500, see the List of CFR Sections Affected, which appears in
the Finding Aids section of the printed volume and on GPO Access.