Cellophane may be safely used for packaging food in accordance with the following prescribed conditions:
(c)List of substances: List of substances Limitations (residue and limits of addition expressed as percent by weight of finished packaging cellophane) Acrylonitrile-butadiene copolymer resins As the basic polymer. Acrylonitrile-butadiene-styrene copolymer resins Do. Acrylonitrile-styrene copolymer resins Do. Acrylonitrile-vinyl chloride copolymer resins Do. N-Acyl sarcosines where the acyl group is lauroyl or stearoyl For use only as release agents in coatings at levels not to exceed a total of 0.3 percent by weight of the finished packaging cellophane. Alkyl ketene dimers identified in § 176.120 of this chapter Aluminum hydroxide Aluminum silicate Ammonium persulfate Ammonium sulfate Behenamide Butadiene-styrene copolymer As the basic polymer. 1,3-Butanediol n-Butyl acetate 0.1 percent. n-Butyl alcohol Do. Calcium ethyl acetoacetate Calcium stearoyl-2-lactylate identified in § 172.844 of this chapter Not to exceed 0.5 percent weight of cellophane. Carboxymethyl hydroxyethylcellulose polymer Castor oil, hydrogenated Castor oil, sulfonated, sodium salt Cellulose acetate butyrate Cellulose acetate propionate Cetyl alcohol Clay, natural Coconut oil fatty acid (C12-C18) diethanolamide, coconut oil fatty acid (C12-C18) diethanolamine soap, and diethanolamine mixture having total alkali (calculated as potassium hydroxide) of 16-18% and having an acid number of 25-35 For use only as an adjuvant employed during the processing of cellulose pulp used in the manufacture of cellophane base sheet. Copal resin, heat processed As basic resin. Damar resin Defoaming agents identified in § 176.200 of this chapter Dialkyl ketones where the alkyl groups are lauryl or stearyl Not to exceed a total of 0.35 percent. Dicyclohexyl phthalate Do. Diethylene glycol ester of the adduct of terpene and maleic anhydride Di(2-ethylhexyl) adipate Di(2-ethylhexyl) phthalate Alone or in combination with other phthalates where total phthalates do not exceed 5 percent. Dimethyldialkyl (C8-C18) ammonium chloride 0.005 percent for use only as a flocculant for slip agents. Di-n-ocyltin bis (2-ethylhexyl maleate) For use only as a stabilizer at a level not to exceed 0.55 percent by weight of the coating solids in vinylidene chloride copolymer waterproof coatings prepared from vinylidene chloride copolymers identified in this paragraph, provided that such vinylidene chloride copolymers contain not less than 90 percent by weight of polymer units derived from vinylidene chloride. N,N′-Dioleoyethylenediamine, N,N′-dilinoleoylethylene-diamine and N-oleoyl-N′linoleoylethylene-diamine mixture produced when tall oil fatty acids are made to react with ethylenediamine such that the finished mixture has a melting point of 212°-228 °F., as determined by ASTM method D127-60 (“Standard Method of Test for Melting Point of Petrolatum and Microcrystalline Wax” (Revised 1960), which is incorporated by reference; copies are available from University Microfilms International, 300 N. Zeeb Rd., Ann Arbor, MI 48106, 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.), and an acid value of 10 maximum 0.5 percent. N,N′-Dioleoylethylenediamine (N,N′-ethylenebisoleamide) Disodium EDTA Distearic acid ester of di(hydroxyethyl) diethylenetriamine monoacetate 0.06 percent. N,N′-Distearoylethylenediamine (N,N′-ethylenebis stearamide) Epoxidized polybutadiene For use only as a primer subcoat to anchor surface coatings to the base sheet. Erucamide Ethyl acetate Ethylene-vinyl acetate copolymers complying with § 177.1350 2-Ethylhexyl alcohol 0.1 percent for use only as lubricant. Fatty acids derived from animal and vegetable fats and oils, and the following salts of such acids, single or mixed: Aluminum, ammonium, calcium, magnesium, potassium, sodium Ferrous ammonium sulfate Fumaric acid Glycerin-maleic anhydride As the basic polymer. Glycerol diacetate Glycerol monoacetate Hydroxyethyl cellulose, water-insoluble Hydroxypropyl cellulose identified in § 172.870 of this chapter Isopropyl acetate Residue limit 0.1 percent Isopropyl alcohol Do. Itaconic acid Lanolin Lauryl alcohol Lauryl sulfate salts: ammonium, magnesium, potassium, sodium Maleic acid 1 percent. Maleic acid adduct of butadienestyrene copolymer Melamine formaldehyde As the basic polymer. Melamine-formaldehyde modified with one or more of the following: Butyl alcohol, diaminopropane, diethylenetriamine, ethyl alcohol, guanidine, imino-bis-butylamine, imino-bis-ethylamine, imino-bis-propylamine, methyl alcohol, polyamines made by reacting ethylenediamine or trimethylenediamine with dichloroethane or dichloropropane, sulfanilic acid, tetraethylenepentamine, triethanolamine, triethylenetetra-mine As the basic polymer, and used as a resin to anchor coatings to substrate. Methyl ethyl ketone Residue limit 0.1 percent Methyl hydrogen siloxane 0.1 percent as the basic polymer. α-Methylstyrene-vinyltoluene copolymer resins (molar ratio 1α-methylstyrene to 3 vinyltoluene) Mineral oil, white Mono- and bis-(octadecyldiethylene oxide) phosphates (CAS Reg. No. 62362-49-6) For use only as a release agent at a level not to exceed 0.6 percent by weight of coatings for cellophane. Naphthalenesulfonic acid-formaldehyde condensate, sodium salt 0.1 percent, for use only as an emulsifier. Nitrocellulose, 10.9 percent-12.2 percent nitrogen Nylon resins complying with § 177.1500 n-Octyl alcohol For use only as a defoaming agent in the manufacture of cellophane base sheet. Olefin copolymers complying with § 177.1520 Oleic acid reacted with N-alkyl trimethylenediamine (alkyl C16 to C18) Oleic acid, sulfonated, sodium salt Oleyl palmitamide N,N′-Oleoyl-stearylethylenediamine (N-(2-stearoyl-aminoethyl)oleamide) Paraffin, synthetic, complying with § 175.250 of this chapter Pentaerythritol tetrastearate 0.1 percent. Polyamide resins derived from dimerized vegetable oil acids (containing not more than 20 percent of monomer acids) and ethylenediamine as the basic resin For use only in cellophane coatings that contact food at temperatures not to exceed room temperature. Polyamide resins having a maximum acid value of 5 and a maximum amine value of 8.5 derived from dimerized vegetable oil acids (containing not more than 10 percent monomer acids), ethylenediamine, and 4,4-bis(4-hydroxyphenyl)pentanoic acid (in an amount not to exceed 10 percent by weight of said polyamide resins) As the basic resin, for use only in coatings that contact food at temperatures not to exceed room temperature provided that the concentration of the polyamido resins in the finished food-contact coating does not exceed 5 milligrams per square inch of food-contact surface. Polybutadiene resin (molecular weight range 2,000-10,200; bromine number range 210-320) For use only as an adjuvant in vinylidene chloride copolymer coatings. Polycarbonate resins complying with § 177.1580 Polyester resin formed by the reaction of the methyl ester of rosin, phthalic anhydride, maleic anhydride, and ethylene glycol, such that the polyester resin has an acid number of 4 to 11, a drop-softening point of 70 °C-92 °C, and a color of K or paler Polyethylene Polyethyleneaminostearamide ethyl sulfate produced when stearic acid is made to react with equal parts of diethylenetriamine and triethylenetetramine and the reaction product is quaternized with diethyl sulfate 0.1 percent. Polyethylene glycol (400) monolaurate Polyethylene glycol (600) monolaurate Polyethylene glycol (400) monooleate Polyethylene glycol (600) monooleate Polyethylene glycol (400) monostearate Polyethylene glycol (600) monostearate Polyethylene, oxidized: complying with the identity prescribed in § 177.1620(a) Polyethylenimine As the basic polymer, for use as a resin to anchor coatings to the substrate and for use as an impregnant in the food-contact surface of regenerated cellulose sheet in an amount not to exceed that required to improve heat-sealable bonding between coated and uncoated sides of cellophane. Polyisobutylene complying with § 177.1420 Polyoxypropylene-polyoxyethylene block polymers (molecular weight 1,900-9,000) For use as an adjuvant employed during the processing of cellulose pulp used in the manufacture of cellophane base sheet. Polypropylene complying with § 177.1520 Polystyrene As the basic polymer. Polyvinyl acetate Do. Polyvinyl alcohol (minimum viscosity of 4 percent aqueous solution at 20 °C of 4 centipoises) Polyvinyl chloride As the basic polymer. Polyvinyl stearate Do. n-Propyl acetate Residue limit 0.1 percent. n-Propyl alcohol Do. Rapeseed oil, blown Rosins and rosin derivatives as provided in § 178.3870 of this chapter Rubber, natural (natural latex solids) Silica Silicic acid Sodium m-bisulfite Sodium dioctyl sulfosuccinate Sodium dodecylbenzenesulfonate Sodium lauroyl sarcosinate 0.35 percent; for use only in vinylidene chloride copolymer coatings. Sodium oleyl sulfate-sodium cetyl sulfate mixture For use only as an emulsifier for coatings; limit 0.005 percent where coating is applied to one side only and 0.01 percent where coating is applied to both sides. Sodium silicate Sodium stearoyl-2-lactylate identified in § 172.846 of this chapter Not to exceed 0.5 percent weight of cellophane. Sodium sulfate Sodium sulfite Spermaceti wax Stannous oleate 2-Stearamido-ethyl stearate Stearyl alcohol Styrene-maleic anhydride resins As the basic polymer. Terpene resins identified in § 172.615 of this chapter Tetrahydrofuran Residue limit of 0.1 percent. Titanium dioxide Toluene Residue limit of 0.1 percent. Toluene sulfonamide formaldehyde 0.6 percent as the basic polymer. Triethylene glycol Triethylene glycol diacetate, prepared from triethylene glycol containing not more than 0.1 percent of diethylene glycol 2,2,4-Trimethyl-1,3 pentanediol diisobutyrate For use only in cellophane coatings and limited to use at a level not to exceed 10 percent by weight of the coating solids except when used as provided in § 178.3740 of this chapter Urea (carbamide) Urea formaldehyde As the basic polymer. Urea formaldehyde modified with methanol, ethanol, butanol diethylenetriamine, triethylenetetramine, tetraethylenepenta-mine, guanidine, sodium sulfite, sulfanilic acid, imino-bis-ethylamine, imino-bis-propylamine, imino-bis-butylamine, diaminopropane, diaminobutane, aminomethylsulfonic acid, polyamines made by reacting ethylenediamine or trimethylenediamine with dichlorethane or dichloropropane As the basic polymer, and used as a resin to anchor coatings to the substrate. Vinyl acetate-vinyl chloride copolymer resins As the basic polymer. Vinyl acetate-vinyl chloride-maleic acid copolymer resins Do. Vinylidene chloride copolymerized with one or more of the following: Acrylic acid, acrylonitrile, butyl acrylate, butyl methacrylate, ethyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, ethyl methacrylate, itaconic acid, methacrylic acid, methyl acrylate, methyl methacrylate, propyl acrylate, propyl methacrylate, vinyl chloride Do. Vinylidene chloride-methacrylate decyloctyl copolymer Do. Wax, petroleum, complying with § 178.3710 of this chapter
177.1210Closures with sealing gaskets for food containers.#
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:
(b)Closure-sealing gaskets and overall discs are formulated from substances identified in § 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:
(5)Substances that may be employed in the manufacture of closure-sealing gaskets include: Table 1 List of substances Limitations (expressed as percent by weight of closure-sealing gasket composition) Arachidy-l-behenyl amide (C20-C22 fatty acid amides) 5 percent. Azodicarbonamide 1. 2 percent. 2. 5 percent; for use only in the manufacture of polyethylene complying with item 2.1 in § 177.1520(c) of this chapter. Balata rubber Benzyl alcohol 1 percent. Brominated isobutylene-isoprene copolymers, produced when isobutylene-isoprene copolymers complying with § 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, 5001 Campus Dr., 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 § 177.1420 Coco amide (coconut oil fatty acids amides) 2 percent. 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 § 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. No. 006422-86-2). For use as a plasticizer at 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 § 176.170(c) of this chapter, table 1, and under conditions of use A through H described in § 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-β-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 § 177.1520(d)(5), and a minimum Mooney viscosity of 35 as determined by the method described in § 177.1520(d)(6) Ethylene-vinyl acetate copolymer Glyceryl mono-12-hydroxystearate (hydrogenated glyceryl ricinoleate) 2 percent. Gutta-percha Hexamethylenetetramine 1 percent. Hexylene glycol 0.5 percent. Isobutylene-isoprene copolymers complying with § 177.1420 Maleic anhydride-polyethylene copolymer 5 percent. Maleic anhydride-styrene copolymer Do. 2,2′-Methylenebis[6-(1-methylcylcohexyl)-p-cresol] 1 percent. Mixed octylated diphenylamine (CAS Reg. No. 68411-46-1) 0.1 percent in isobutylene-isoprene and chlorinated isobutylene-isoprene copolymers complying with § 177.1420, and brominated isobutylene-isoprene copolymers complying with this section. Naphthalene sulfonic acid-formaldehyde condensate, sodium salt 0.2 percent. Natural rubber (crepe, latex, mechanical dispersions) α-cis-9-Octadecenyl-omega-hydroxypoly (oxyethylene); the octadecenyl group is derived from oleyl alcohol and the poly (oxyethylene) content averages 20 moles 0.5 percent. Oleyl alcohol 1 percent. 4,4′-Oxybis (benzene sulfonyl hydrazide) 0.5 percent. Paraformaldehyde 1 percent. Polybutadiene Poly-p-dinitroso benzene (activator for butyl rubber) 1 percent; for use only in vulcanized natural or synthetic rubber gasket compositions. Polyethylene glycol 400 esters of fatty acids derived from animal and vegetable fats and oils 1 percent. Polyisobutylene complying with § 177.1420 Polyoxypropylene-polyoxyethylene condensate, average mol. wt. 2750-3000 0.05 percent. Polyurethane resins manufactured from diphenylmethane diisocyanate, 1,4-butanediol, and adipic acid (CAS Reg. No. 26375-23-5). For use only: No limitation on amount used, but for use only in closure 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 § 176.170(c) of this chapter, tables 1 and 2, respectively. Potassium benzoate 1 percent. 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 § 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 § 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 tetradecyl sulfate) 0.6 percent. 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 naphthalenesulfonic acid 0.2 percent. 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) phosphite 1 percent. Vinyl chloride-vinyl stearate copolymer Zinc dibutyldithiocarbamate 0.8 percent; for use only in vulcanized natural or synthetic rubber gasket compositions. Table 2—Maximum Extractives Tolerances[In parts per million] Type of closure-sealing gasket composition Chloroform fraction of water extractives Chloroform fraction of heptane extractives Chloroform fraction of alcohol extractives 1. Plasticized polymers, 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 50 500 50 2. Preformed overall discs or annular rings of plasticized polymers, including unvulcanized natural or synthetic rubber 50 250 50 3. Preformed overall discs or annular rings of vulcanized plasticized polymers, including natural or synthetic rubber 50 50 50 4. Preformed overall discs or annular rings of polymeric or resinous-coated paper, paperboard, plastic, or metal foil substrates 50 250 50 5. Closures with sealing gaskets or sealing compositions as described in 1, 2, 3, and 4, and including paper, paperboard, and glassine used for dry foods only (1) (1) (1) 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 § 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 Conditions of use Types of food(see Table 3) Extractant Water (time and temperature) Heptane1 (time and temperature) 8% alcohol(time and temperature) A. High temperature heat-sterilized (e.g., over 212 °F) I, IV-B 250 °F, 2 hr 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 above 150 °F II, IV-B Fill boiling, cool to 100 °F III, IV-A do 120 °F, 15 min V do D. Hot filled or pasteurized below 150 °F II, IV-B, VI-B 150 °F, 2 hr III, IV-A do 100 °F, 30 min V do VI-A 150 °F, 2 hr. E. Room temperature filled and stored (no thermal treatment in the container) II, IV-B, VI-B 120 °F, 24 hr III, IV-A do 70 °F, 30 min V do VI-A 120 °F, 24 hr. F. Refrigerated storage (no thermal treatment) I, II, III, IV-A, IV-B, VI-B,VII 70 °F, 48 hr 70 °F, 30 min VI-A 70 °F, 48 hr. G. Frozen storage (no thermal treatment in the container) I, II, III, IV-B, VII 70 °F, 24 hr 1 Heptane extractant not applicable to closure-sealing gaskets overcoated with wax.
Ionomeric resins manufactured from either ethylene-methacrylic acid copolymers (and/or their ammonium, calcium, magnesium, potassium, sodium, and/or zinc partial salts), ethylene-methacrylic acid-vinyl acetate copolymers (and/or their ammonium, calcium, magnesium, potassium, sodium, and/or zinc partial salts,), or methacrylic acid polymers with ethylene and isobutyl acrylate (and/or their potassium, sodium and/or zinc partial salts) may be safely used as articles or components of articles intended for use in contact with food, in accordance with the following prescribed conditions:
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.
(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 °C, after which the kettle may be rapidly cooled to 25 °C-30 °C by immersing in a cold water bath. Transfer the kettle to a constant temperature bath set to maintain 25 °C ±0.1 °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. 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.
177.2600Rubber articles intended for repeated use.#
Rubber articles intended for repeated use may be safely used in producing, manufacturing, packing, processing, preparing, treating, packaging, transporting, or holding food, subject to the provisions of this section.
(d)Activators (total not to exceed 5 percent by weight of rubber product except magnesium oxide may be used at higher levels). Diethylamine. Fatty acid amines, mixed. Fatty acids. Magnesium carbonate. Magnesium oxide, light and heavy. Oleic acid, dibutylamine salt (dibutylammonium oleate). Stannous chloride. Tall oil fatty acids. Tetrachloro-p-benzoquinone. Triethanolamine. Zinc salts of fatty acids.