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.

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.

Specifications:

The analytical methods for determining conformance with specifications for styrene-maleic anhydride copolymers prescribed in this section are as follows:

Molecular weight. Molecular weight shall be determined by membrane osmometry.

Residual styrene monomer content. Residual styrene monomer content shall be determined by the method described in § 177.1640(d).

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, 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.

The provisions of this section are not applicable to styrene-maleic anhydride copolymers listed in other sections of this subpart.