§177.1020 Acrylonitrile/butadiene/sty-rene co-polymer.
Acrylonitrile/butadiene/styrene copolymer identified in this section may be safely used as an article or component of articles intended for use with all foods, except those containing alcohol, under conditions of use E, F, and G described in table 2 of § 176.170（c） of this chapter.
（a） Identity. For the purpose of this section, the acrylonitrile/butadiene/styrene copolymer consists of:
（1） Eighty-four to eighty-nine parts by weight of a matrix polymer containing 73 to 78 parts by weight of acrylonitrile and 22 to 27 parts by weight of styrene; and
（2） Eleven to sixteen parts by weight of a grafted rubber consisting of （i） 8 to 13 parts of butadiene/styrene elastomer containing 72 to 77 parts by weight of butadiene and 23 to 28 parts by weight of styrene and （ii） 3 to 8 parts by weight of a graft polymer having the same composition range as the matrix polymer.
（b） Adjuvants. The copolymer identified in paragraph （a） of this section may contain adjuvant substances required in its production. Such adjuvants may include substances generally recognized as safe in food, substances used in accordance with prior sanction, substances permitted in this part, and the following:
| Substance | Limitations |
| 2-Mercapto- ethanol | The finished copolymer shall contain not more than 100 ppm 2-mercaptoethanol acrylonitrile adduct as determined by a method titled “Analysis of Cycopac Resin for Residual β-(2-Hydroxyethylmercapto) propionitrile,” which is incorporated by reference. Copies are available from the Bureau of Foods (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. |
（c） Specifications. （1） Nitrogen content of the copolymer is in the range of 16 to 18.5 percent as determined by Micro-Kjeldahl analysis.
（2） Residual acrylonitrile monomer content of the finished copolymer articles is not more than 11 parts per million as determined by a gas chromatographic method titled “Determination of Residual Acrylonitrile and Styrene Monomers-Gas Chromatographic Internal Standard Method,” 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.
（d） Extractive limitations. （1） Total nonvolatile extractives not to exceed 0.0005 milligram per square inch surface area when the finished food contact article is exposed to distilled water, 3 percent acetic acid, or n- heptane for 8 days at 120 °F.
（2） The finished food-contact article shall yield not more than 0.0015 milligram per square inch of acrylonitrile monomer when exposed to distilled water and 3 percent acetic acid at 150 °F for 15 days when analyzed by a polarographic method titled “Extracted Acrylonitrile by Differential Pulse Polarography,” 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.
（e） Acrylonitrile copolymers identified in this section shall comply with the provisions of § 180.22 of this chapter.
（f） 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 48543, Sept. 23, 1977; 47 FR 11841, Mar. 19, 1982; 54 FR 24897, June 12, 1989]
