Acrylonitrile/styrene copolymers identified in this section may be safely used as a component of packaging materials subject to the provisions of this section.
(a) Identity. For the purposes of this section acrylonitrile/styrene copoly-mers are basic copolymers meeting the specifications prescribed in paragraph (c) of this section.
(b) Adjuvants. (1) The copolymers identified in paragraph (c) of this section may contain adjuvant substances required in their production, with the exception that they shall not contain mercaptans or other substances which form reversible complexes with acryl-onitrile monomer. Permissible adjuvants may include substances generally recognized as safe in food, substances used in accordance with prior sanction, substances permitted under applicable regulations in this part, and those authorized in paragraph (b)(2) of this section.
(2) The optional adjuvants for the acrylonitrile/styrene copolymer identified in paragraphs (c)(1) and (3) of this section are as follows:
Substances
| Limitation
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Condensation polymer of toluene sulfonamide and formaldehyde | 0.15 pct maximum. |
(c) Specifications.
Acrylonitrile/styrene copolymers
| Maximum residual acrylonitrile monomer content of finished article
| Nitrogen content of copolymer
| Maximum extractable fractions at specified temperatures and times
| Conformance with certain specifications
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1. Acrylonitrile/styrene copolymer consisting of the copolymer produced by polymerization of 66-72 parts by weight of acrylonitrile and 28-34 parts by weight of styrene; for use with food of Type VI-B identified in table 1 of § 176.170(c) of this chapter under conditions of use C, D, E, F, G described in table 2 of § 176.170(c) of this chapter | 80 ppm
1 | 17.4 to 19 pct | Total nonvolatile extractives not to exceed 0.01 mg/in
2 surface area of the food contact article when exposed to distilled water and 3 pct acetic acid for 10 d at 66 deg.C (150 deg.F)
The extracted copolymer shall not exceed 0.001 mg/in
2 surface area of the food contact article when exposed to distilled water and 3 pct acetic acid for 10 d at 66 deg.C (150 deg.F)
1 | Minimum number average molecular weight is 30,000.
1
| 2. Acrylonitrile/styrene copolymer consisting of the copolymer produced by polymerization of 45-65 parts by weight of acrylonitrile and 35-55 parts by weight of styrene; for use with food of Types, I, II, III, IV, V, VI (except bottles), VII, VIII, and IX identified in table 1 of § 176.170(c) of this chapter under conditions B (not to exceed 93 deg.C (200 deg.F)), C, D, E, F, G described in table 2 of § 176.170(c) of this chapter | 50 ppm
1 | 12.2 to 17.2 pct | Extracted copolymer not to exceed 2.0 ppm in aqueous extract or n-heptane extract obtained when 100 g sample of the basic copolymer 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 is extracted with 250 mil of deionized water or reagent grade n-heptane at reflux temperature for 2 h.
1 | Minimum 10 pct solution viscosity at 25 deg.C (77 deg.F) is 10cP.
1
| 3. Acrylonitrile/styrene copolymer consisting of the copolymer produced by polymerization of 66-72 parts by weight of acrylonitrile and 28-34 parts by weight of styrene; for use with food of Types VI-A and VI-B identified in table 1 of § 176.170(c) of this chapter under conditions of use C, D, E, F, G described in table 2 of § 176.170(c) of this chapter | 0.10 ppm (calculated on the basis of the weight of the acrylonitrile copolymer resin in the finished articles).
2 | 17.4 to 19 pct | Total nonvolatile extractives not to exceed 0.01 mg/in
2 surface area of the food contact article when exposed to distilled water and 3 pct acetic acid for 10 d at 66 deg.C (150 deg.F)
The extracted copolymer shall not exceed 0.001 mg/in
2 surface area of the food contact article when exposed to distilled water and 3 pct acetic acid for 10 d at 66 deg.C (150 deg.F).
1 | Maximum carbon dioxide permeability at 23 deg.C (73 deg.F) for the finished article is 0.04 barrer.
3
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(d) Interim listing. Acrylonitrile copolymers identified in this section shall comply with the provisions of § 180.22 of this chapter.
(e) Acrylonitrile copolymer identified in this section may be used to fabricate beverage containers only if they comply with the specifications of item 3 in paragraph (c) of this section.
[42 FR 14572, Mar. 15, 1977, as amended at 42 FR 48543, Sept. 23, 1977; 47 FR 11841, Mar. 19, 1982; 49 FR 36643, Sept. 19, 1984; 52 FR 33803, Sept. 8, 1987]
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