Styrene-maleic anhydride copolymers identified 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 provisions of this section.
(a) For the purpose of this section, styrene-maleic anhydride copolymers are those produced by the polymerization of styrene and maleic anhydride so that the finished polymers meet the specifications prescribed in paragraph (b) of this section, when tested by the methods described in paragraph (c) of this section.
(b) Specifications: ----------------------------------------------------------------------------------------------------------------
Maximum Maximum
extractable extractable
Molecular Residual fraction in fraction in n-
weight Residual maleic distilled water heptane at
Styrene-maleic copolymers (minimum styrene anhydride at specified specified
number monomer monomer temperatures, temperatures,
average) times, and times, and
particle size particle size----------------------------------------------------------------------------------------------------------------1. Styrene-maleic anhydride 70,000 0.3 weight 0.1 weight 0.006 weight 0.02 weight
copolymers containing not more percent. percent. percent at percent at 73 F
than 15 pct maleic anhydride reflux for 2 hr
units by weight; for use as temperature for utilizing
articles or as components of 1 hr utilizing particles of a
articles that contact food of particles of a size that will
Types I, II, III, IV-A, IV-B, size that will pass through a
V, VI-B (except carbonated pass through a U.S. standard
beverages), VII-A, VII-B, U.S. standard sieve No. 10 and
VIII, and IX identified in sieve No. 10 and will be held on
table 1 in Sec. 176.170(c) of will be held on a U.S. standard
this chapter under conditions a U.S. standard sieve No. 20.
of use B, C, D, E, F, G, and H sieve No. 20.
described in table 2 in Sec.
176.170(c) of this chapter.2. Styrene-maleic anhydride .......... 0.3........... 0.1.......... 0.015 weight 1.0 weight
copolymer modified with percent at percent at 23 C
butadiene, (CAS Reg. No. 27288- reflux (73 F) for 2
99-9) containing not more than temperature for hours utilizing
15 percent maleic anhydride 1 hour utilizing particles of a
units by weight and not more particles of a size that will
than 20 percent styrene- size that will pass through a
butadiene and/or butadiene pass through a U.S. standard
rubber units by weight; for U.S. standard sieve No. 10 and
use (except carbonated sieve No. 10 and will be held on
beverage bottles) as articles will be held on a U.S. standard
or as components of articles a U.S. standard sieve No. 20.
that contact food of Types I, sieve No. 20.
II, III, IV-A, IV-B, V, VI,
VII-A, VII-B, VIII, and IX
identified in table I in Sec.
176.170(c) of this chapter
under conditions of use B, C,
D, E, F, G, and H described in
table 2 in Sec. 176.170(c) of
this chapter.----------------------------------------------------------------------------------------------------------------
(c) The analytical methods for determining conformance with specifications for styrene-maleic anhydride copolymers prescribed in this section are as follows:
(1) Molecular weight. Molecular weight shall be determined by membrane osmometry.
(2) Residual styrene monomer content. Residual styrene monomer content shall be determined by the method described in Sec. 177.1640(d).
(3) Residual maleic anhydride monomer content. Residual maleic anhydride monomer content shall be determined by a gas chromatographic method titled ``Determination of Residual Maleic Anhydride in Polymers by Gas Chromatography,'' 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) The provisions of this section are not applicable to styrene-maleic anhydride copolymers listed in other sections of this subpart. [42 FR 14572, Mar. 15, 1977, as amended at 47 FR 11844, Mar. 19, 1982; 47 FR 14698, Apr. 6, 1982; 54 FR 24898, June 12, 1989]