[Code of Federal Regulations] [Title 21, Volume 3] [Revised as of April 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 21CFR177.1480] [Page 270-271] 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. 177.1480 Nitrile rubber modified acrylonitrile-methyl acrylate copolymers. Nitrile rubber modified acrylonitrile-methyl acrylate copolymers identified in this section may be safely used as components of articles intended for food-contact use under conditions of use D, E, F, or G described in table 2 of Sec. 176.170(c) of this chapter, subject to the provisions of this section. (a) For the purpose of this section, nitrile rubber modified acrylonitrile-methyl acrylate copolymers consist of basic copolymers produced by the graft copolymerization of 73-77 parts by weight of acrylonitrile and 23-27 parts by weight of methyl acrylate in the presence of 8-10 parts by weight of butadiene-acrylonitrile copolymers containing approximately 70 percent by weight of polymer units derived from butadiene. (b) The nitrile rubber modified acrylonitrile-methyl acrylate basic copolymers meet the following specifications and extractives limitations: (1) Specifications. (i) Nitrogen content is in the range 16.5-19 percent as determined by Kjeldahl analysis. (ii) Intrinsic viscosity in acetonitrile at 25 [deg]C is not less than 0.29 deciliter per gram as determined by ASTM method D1243-79, ``Standard Test Method for Dilute Solution Viscosity of Vinyl Chloride Polymers,'' which is incorporated by reference. Copies may be obtained from the American Society for Testing Materials, 1916 Race St., Philadelphia, PA 19103, or may be examined at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC 20408. (iii) Residual acrylonitrile monomer content is not more than 11 parts per million as determined by gas chromatography. (iv) Acetonitrile-soluble fraction after refluxing the base polymer in acetonitrile for 1 hour is not greater than 95 percent by weight of the basic copolymers. (2) Extractives limitations. The following extractive limitations are determined by an infrared spectrophotometric method titled, ``Infrared Spectrophotometric Determination of Polymer Extracted from Borex[reg] 210 Resin Pellets,'' 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 Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC 20408, and are applicable to the basic copolymers in the form of particles of a size that will pass through a U.S. standard sieve No. 6 and that will be held on a U.S. standard sieve No. 10: [[Page 271]] (i) Extracted copolymer not to exceed 2.0 parts per million in aqueous extract obtained when a 100-gram sample of the basic copolymers is extracted with 250 milliliters of demineralized (deionized) water at reflux temperature for 2 hours. (ii) Extracted copolymer not to exceed 0.5 part per million in n- heptane extract obtained when a 100-gram sample of the basic copolymers is extracted with 250 milliliters of reagent grade n-heptane at reflux temperature for 2 hours. (c) Acrylonitrile copolymers identified in this section shall comply with the provisions of Sec. 180.22 of this chapter. (d) Acrylonitrile copolymers identified in this section are not authorized to be used to fabricate beverage containers. [42 FR 14572, Mar. 15, 1977, as amended at 42 FR 48544, Sept. 23, 1977; 47 FR 11843, Mar. 19, 1982; 47 FR 16775, Apr. 20, 1982; 49 FR 10109, Mar. 19, 1984; 54 FR 24898, June 12, 1989; 61 FR 14481, Apr. 2, 1996]