Closures with sealing gaskets may be safely used on containers intended for use in producing, manufacturing, packing, processing, preparing, treating, packaging, transporting, or holding food in accordance with the following prescribed conditions:
(a) Closures for food containers are manufactured from substances generally recognized as safe for contact with food; substances that are subject to the provisions of prior sanctions; substances authorized by regulations in parts 174, 175, 176, 177, 178 and Sec. 179.45 of this chapter; and closure-sealing gaskets, as further prescribed in this section.
(b) Closure-sealing gaskets and overall discs are formulated from substances identified in Sec. 175.300(b) of this chapter, with the exception of paragraph (b)(3) (v), (xxxi), and (xxxii) of that section, and from other optional substances, including the following:
(1) Substances generally recognized as safe in food.
(2) Substances used in accordance with the provisions of a prior sanction or approval within the meaning of section 201(s) of the act.
(3) Substances that are the subject of regulations in parts 174, 175, 176, 177, 178 and Sec. 179.45 of this chapter and used in accordance with the conditions prescribed.
(4) Substances identified in paragraph (b)(5) of this section, used in amounts not to exceed those required to accomplish the intended physical or technical effect and in conformance with any limitation provided; and further provided that any substance employed in the production of closure-sealing gasket compositions that is the subject of a regulation in parts 174, 175, 176, 177, 178 and Sec. 179.45 of this chapter conforms with the identity or specifications prescribed.
(5) Substances that may be employed in the manufacture of closure-sealing gaskets include:
Table 1------------------------------------------------------------------------
Limitations (expressed as
List of substances percent by weight of closure-
sealing gasket composition)------------------------------------------------------------------------Arachidy-l-behenyl amide (C20-C22fatty 5 percent.
acid amides).Azodicarbonamide....................... 1. 2 percent.
2. 5 percent; for use only in
the manufacture of
polyethylene complying with
item 2.1 in Sec. 177.1520(c)
of this chapter.Balata rubber..........................Benzyl alcohol......................... 1 percent.Brominated isobutylene-isoprene
copolymers, produced when isobutylene-
isoprene copolymers complying with
Sec. 177.1420(a)(2) are modified by
bromination with not more than 2.3
weight-percent of bromine and having a
Mooney Viscosity (ML 1+8 (125 C)) of
27 or higher. The viscosity is
determined by the American Society for
Testing and Materials (ASTM) method D
1646-81, ``Standard Test Method for
Rubber--Viscosity and Vulcanization
Characteristics (Mooney Viscometer),''
which is incorporated by reference in
accordance with 5 U.S.C. 522(a) and 1
CFR part 51. Copies are available from
the AOAC INTERNATIONAL, 481 North
Frederick Ave., Suite 500,
Gaithersburg, MD 20877-2504 and 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..1,3-Butanediol.........................Calcium tin stearate................... 2 percent.Calcium zinc stearate.................. Do.Carbon, activated...................... 1 percent.Castor oil, hydrogenated............... 2 percent.Chlorinated isobutylene-isoprene
copolymers complying with Sec.
177.1420.Coco amide (coconut oil fatty acids 2 percent.
amides).Cork (cleaned, granulated).............Diebenzamide phenyl disulfide.......... 1 percent; for use only in
vulcanized natural or
synthetic rubber gasket
compositions.Di(C7, C9-alkyl) adipate............... Complying with Sec. 178.3740
of this chapter; except that,
there is no limitation on
polymer thickness.Di-2-ethylhexyl adipate................Di-2-ethylhexyl sebacate............... 2 percent.Di-2-ethylhexyl terephthalate (CAS Reg. For use as a plasticizer at
No. 006422-86-2).. levels not exceeding 75 parts
per hundred by weight of
permitted vinyl chloride homo-
and/or copolymer resins used
in contact with food of Types
I, II, IV-B, VI-A, VI-B, VI-C
(up to 15 percent alcohol by
volume), VII-B, and VIII
described in Sec. 176.170(c)
of this chapter, table 1, and
under conditions of use A
through H described in Sec.
176.170 (c) of this chapter,
table 2.Dihexyl ester of sodium sulfosuccinate. 1 percent.Diisodecyl phthalate................... No limitation on amount used
but for use only in closure-
sealing gasket compositions
used in contact with non-fatty
foods containing no more than
8 percent of alcohol.Di-[beta]-naphthyl-p-phenylenediamine.. 1 percent.Dipentamethylenethiurametetrasulfide... 0.4 percent; for use only in
vulcanized natural or
synthetic rubber gasket
compositions.Eicosane (technical grade) (water-white
mixture of predominantly straight-
chain paraffin hydrocarbons averaging
20 carbon atoms per molecule).Epoxidized linseed oil.................Epoxidized linseed oil modified with
trimellitic anhydride.Epoxidized safflower oil...............Epoxidized safflower oil modified with
trimellitic anhydride.Epoxidized soybean oil modified with
trimellitic anhydride.
Erucylamide............................ 5 percent.Ethylene-propylene copolymer...........Ethylene-propylene modified copolymer
elastomers produced when ethylene and
propylene are copolymerized with 5-
methylene-2-norbornene and/or 5-
ethylidine-2-norbornene. The finished
copolymer elastomers so produced shall
contain not more than 5 weight-percent
of total polymer units derived from 5-
methylene-2-norbornene and/or 5-
ethylidine-2-norbornene, and shall
have a minimum viscosity average
molecular weight of 120,000 as
determined by the method described in
Sec. 177.1520(d)(5), and a minimum
Mooney viscosity of 35 as determined
by the method described in Sec.
177.1520(d)(6).Ethylene-vinyl acetate copolymer.......Glyceryl mono-12-hydroxystearate 2 percent.
(hydrogenated glyceryl ricinoleate).Gutta-percha...........................Hexamethylenetetramine................. 1 percent.Hexylene glycol........................ 0.5 percent.Isobutylene-isoprene copolymers
complying with Sec. 177.1420.Maleic anhydride-polyethylene copolymer 5 percent.Maleic anhydride-styrene copolymer..... Do.2,2'-Methylenebis[6-(1- 1 percent.
methylcylcohexyl)-p-cresol].Mixed octylated diphenylamine (CAS Reg. 0.1 percent in isobutylene-
No. 68411-46-1). isoprene and chlorinated
isobutylene-isoprene
copolymers complying with Sec.
177.1420, and brominated
isobutylene-isoprene
copolymers complying with this
section.Naphthalene sulfonic acid-formaldehyde 0.2 percent.
condensate, sodium salt.Natural rubber (crepe, latex,
mechanical dispersions).[alpha]-cis-9-Octadecenyl-omega- 0.5 percent.
hydroxypoly (oxyethylene); the
octadecenyl group is derived from
oleyl alcohol and the poly
(oxyethylene) content averages 20
moles.Oleyl alcohol.......................... 1 percent.4,4'-Oxybis (benzene sulfonyl 0.5 percent.
hydrazide).Paraformaldehyde....................... 1 percent.Polybutadiene..........................Poly-p-dinitroso benzene (activator for 1 percent; for use only in
butyl rubber). vulcanized natural or
synthetic rubber gasket
compositions.Polyethylene glycol 400 esters of fatty 1 percent.
acids derived from animal and
vegetable fats and oils.Polyisobutylene complying with Sec.
177.1420.Polyoxypropylene-polyoxyethylene 0.05 percent.
condensate, average mol. wt. 2750-3000.Polyurethane resins manufactured from For use only:
diphenylmethane diisocyanate, 1,4- No limitation on amount used,
butanediol, and adipic acid (CAS Reg. but for use only in closure
No. 26375-23-5).. gasket compositions used in
contact with food types VI-A
and VI-C (up to 15 percent
alcohol) under conditions of
use D, E, F, and G, as
described in Sec. 176.170(c)
of this chapter, tables 1 and
2, respectively.Potassium benzoate..................... 1 percent.Potassium perchlorate.................. Do.Potassium propionate................... 2 percent.Potassium and sodium persulfate........ 1 percent.Resorcinol............................. 0.24 percent; for use only as a
reactive adjuvant substance
employed in the production of
gelatin-bonded cord
compositions for use in lining
crown closures. The gelatin so
used shall be technical grade
or better.Rosins and rosin derivatives as defined
in Sec. 175.300(b)(3)(v) of this
chapter for use only in resinous and
polymeric coatings on metal
substrates; for all other uses as
defined in Sec. 178.3870 of this
chapter.Sodium cetyl sulfate................... 1 percent.Sodium decylbenzenesulfonate........... Do.Sodium decyl sulfate................... Do.Sodium formaldehyde sulfoxylate........ 0.05 percent.Sodium lauryl sulfate.................. 1 percent.Sodium lignin sulfonate................ 0.2 percent.Sodium myristyl sulfate (sodium 0.6 percent.
tetradecyl sulfate).
Sodium nitrite......................... 0.2 percent; for use only in
annular ring gaskets applied
in aqueous dispersions to
closures for containers having
a capacity of not less than 5
gallons.Sodium o-phenylphenate................. 0.05 percent.Sodium polyacrylate.................... 5 percent.Sodium and potassium pentachlorophenate 0.05 percent.Sodium salt of trisopropyl 0.2 percent.
naphthalenesulfonic acid.Sodium tridecylsulfate................. 0.6 percent.Stearic acid amide..................... 5 percent.Sulfur................................. For use only as a vulcanizing
agent in vulcanized natural or
synthetic rubber gasket
compositions at a level not to
exceed 4 percent by weight of
the elastomer content of the
rubber gasket composition.Tallow, sulfated....................... 1 percent.Tin-zinc stearate...................... 2 percent.Tri(mixed mono- and dinonylphenyl) 1 percent.
phosphite.Vinyl chloride-vinyl stearate copolymerZinc dibutyldithiocarbamate............ 0.8 percent; for use only in
vulcanized natural or
synthetic rubber gasket
compositions.------------------------------------------------------------------------
Table 2--Maximum Extractives Tolerances
[In parts per million]------------------------------------------------------------------------
Chloroform Chloroform Chloroform
Type of closure-sealing gasket fraction of fraction of fraction of
composition water heptane alcohol
extractives extractives extractives------------------------------------------------------------------------1. Plasticized polymers, 50 500 50
including unvulcanized or
vulcanized or otherwise cured
natural and synthetic rubber
formed in place as overall discs
or annular rings from a hot
melt, solution, plastisol,
organisol, mechanical
dispersion, or latex............2. Preformed overall discs or 50 250 50
annular rings of plasticized
polymers, including unvulcanized
natural or synthetic rubber.....3. Preformed overall discs or 50 50 50
annular rings of vulcanized
plasticized polymers, including
natural or synthetic rubber.....4. Preformed overall discs or 50 250 50
annular rings of polymeric or
resinous-coated paper,
paperboard, plastic, or metal
foil substrates.................5. Closures with sealing gaskets (\1\) (\1\) (\1\)
or sealing compositions as
described in 1, 2, 3, and 4, and
including paper, paperboard, and
glassine used for dry foods only------------------------------------------------------------------------\1\ Extractability tests not applicable.
(c) The closure assembly to include the sealing gasket or sealing compound, together with any polymeric or resinous coating, film, foil, natural cork, or glass that forms a part of the food-contact surface of the assembly, when extracted on a suitable glass container with a solvent or solvents characterizing the type of foods, and under conditions of time and temperature characterizing the conditions of its use as determined from tables 3 and 4 shall yield net chloroform-soluble extractives (corrected for zinc as zinc oleate) not to exceed the tolerances specified in table 2, calculated on the basis of the water capacity of the container on which the closure is to be used. Employ the analytical method described in Sec. 175.300 of this chapter, adapting the procedural details to make the method applicable to closures; such as, for example, placing the closed glass container on its side to assure contact of the closure's food-contacting surface with the solvent.
Table 3--Types of Food I. Nonacid (pH above 5.0), aqueous products; may contain salt or sugar or both, and including oil-in-water emulsions of low- or high-fat content.II. Acidic (pH 5.0 or below), aqueous products; may contain salt or sugar or both, and including oil-in-water emulsions of low- or high-fat content.III. Aqueous, acid or nonacid products containing free oil or fat; may contain salt, and including water-in-oil emulsions of low- or high-fat content.IV. Dairy products and modifications:
A. Water-in-oil emulsions, high- or low-fat.
B. Oil-in-water emulsions, high- or low-fat.V. Low-moisture fats and oils.VI. Beverages:
A. Containing alcohol.
B. Nonalcoholic.VII. Bakery products.VIII. Dry solids (no end-test required).
Table 4--Test Procedures With Time-Temperature Conditions for Determining Amount of Extractives From Closure-
Sealing Gaskets, Using Solvents Simulating Types of Foods and Beverages----------------------------------------------------------------------------------------------------------------
Extractant
Types of food (see -----------------------------------------------------------
Conditions of use Table 3) Water (time and Heptane\1\ (time 8% alcohol (time
temperature) and temperature) and temperature)----------------------------------------------------------------------------------------------------------------A. High temperature heat- I, IV-B........... 250 F, 2 hr....... ..................
sterilized (e.g., over 212 F).
III, IV-A, VII.... do................ 150 F, 2 hr.......B. Boiling water-sterilized..... II................ 212 F, 30 min..... ..................
III, VII.......... do................ 120 F, 30 min.....C. Hot filled or pasteurized II, IV-B.......... Fill boiling, cool ..................
above 150 F. to 100 F.
III, IV-A......... do................ 120 F, 15 min.....
V................. .................. do................D. Hot filled or pasteurized II, IV-B, VI-B.... 150 F, 2 hr....... ..................
below 150 F.
III, IV-A......... do................ 100 F, 30 min.....
V................. .................. do................
VI-A.............. .................. .................. 150 F, 2 hr.E. Room temperature filled and II, IV-B, VI-B.... 120 F, 24 hr...... ..................
stored (no thermal treatment in
the container).
III, IV-A......... do................ 70 F, 30 min......
V................. .................. do................
VI-A.............. .................. .................. 120 F, 24 hr.F. Refrigerated storage (no I, II, III, IV-A, 70 F, 48 hr....... 70 F, 30 min......
thermal treatment). IV-B, VI-B,VII.
VI-A.............. .................. .................. 70 F, 48 hr.G. Frozen storage (no thermal I, II, III, IV-B, 70 F, 24 hr....... ..................
treatment in the container). VII.----------------------------------------------------------------------------------------------------------------\1\Heptane extractant not applicable to closure-sealing gaskets overcoated with wax. [42 FR 14572, Mar. 15, 1977; 42 FR 56728, Oct. 28, 1977, as amended at 47 FR 22090, May 21, 1982; 49 FR 5748, Feb. 15, 1984; 55 FR 34555, Aug. 23, 1990; 61 FR 14480, Apr. 2, 1996; 65 FR 26745, May 9, 2000; 65 FR 52908, Aug. 31, 2000; 70 FR 67651, Nov. 8, 2005; 76 FR 59249, Sept. 26, 2011; 78 FR 14665, Mar. 7, 2013]