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.
(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------------------------------------------------------------------------Condensation polymer of toluene 0.15 pct maximum.
sulfonamide and formaldehyde.------------------------------------------------------------------------
(c) Specifications. ----------------------------------------------------------------------------------------------------------------
Maximum
Maximum residual extractable
acrylonitrile Nitrogen fractions at Conformance withAcrylonitrile/styrene copolymers monomer content content of specified certain specifications
of finished copolymer temperatures and
article times----------------------------------------------------------------------------------------------------------------1. Acrylonitrile/styrene 80 ppm\1\....... 17.4 to 19 pct. Total nonvolatile Minimum number average
copolymer consisting of the extractives not molecular weight is
copolymer produced by to exceed 0.01 mg/ 30,000. \1\
polymerization of 66-72 parts in \2\ surface
by weight of acrylonitrile and area of the food
28-34 parts by weight of contact article
styrene; for use with food of when exposed to
Type VI-B identified in table 1 distilled water
of Sec. 176.170(c) of this and 3 pct acetic
chapter under conditions of use acid for 10 d at
C, D, E, F, G described in 66 C (150 F).
table 2 of Sec. 176.170(c) of The extracted
this chapter. 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 C (150 F) \1\.2. Acrylonitrile/styrene 50 ppm\1\....... 12.2 to 17.2 Extracted Minimum 10 pct solution
copolymer consisting of the pct. copolymer not to viscosity at 25 C (77
copolymer produced by exceed 2.0 ppm in F) is 10cP. \1\
polymerization of 45-65 parts aqueous extract
by weight of acrylonitrile and or n-heptane
35-55 parts by weigth of extract obtained
styrene; for use with food of when 100 g sample
Types, I, II, III, IV, V, VI of the basic
(except bottles), VII, VIII, copolymer in the
and IX identified in table 1 of form of particles
Sec. 176.170(c) of this of a size that
chapter under conditions B (not will pass through
to exceed 93 C (200 F)), C, D, a U.S. Standard
E, F, G described in table 2 of Sieve No. 6 and
Sec. 176.170(c) of this that will be held
chapter. 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\
3. Acrylonitrile/styrene 0.10 ppm 17.4 to 19 pct. Total nonvolatile Maximum carbon dioxide
copolymer consisting of the (calculated on extractives not permeability at 23 C
copolymer produced by the basis of to exceed 0.01 mg/ (73 F) for the
polymerization of 66-72 parts the weight of in \2\ surface finished article is
by weight of acrylonitrile and the area of the food 0.04 barrer. \3\
28-34 parts by weight of acrylonitrile contact article
styrene; for use with food of copolymer resin when exposed to
Types VI-A and VI-B identified in the finished distilled water
in table 1 of Sec. 176.170(c) articles). \2\ and 3 pct acetic
of this chapter under acid for 10 d at
conditions of use C, D, E, F, G 66 C (150 F).
described in table 2 of Sec. The extracted
176.170(c) of this chapter. 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 C (150 F). \1\.----------------------------------------------------------------------------------------------------------------\1\ Use methods for determination of residual acrylonitrile monomer content, maximum extractable fraction,
number average molecular weight, and solution viscosity, titled: ``Determination of Residual Acrylonitrile and
Styrene Monomers-Gas Chromatographic Internal Standard Method''; ``Infrared Spectrophotometric Determination
of Polymer Extracted from Barex 210 Resin Pellets''; ``Procedure for the Determination of Molecular Weights of
Acrylonitrile/Styrene Copolymers,'' and ``Analytical Method for 10% Solution Viscosity of Tyril,'' which are
incorproated by reference. Copies are available from the Center for Food Safety and Applied Nutrition (HFS-
200), 5100 Paint Branch Pkwy., College Park, MD 20740, or may be examined 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.\2\ As determined by the method titled ``Headspace Sampling and Gas-Solid Chromatographic Determination of
Residual Acrylonitrile in Acrylonitrile Copolyemr Solutions,'' which is incorporated by reference. Copies are
available from the Center for Food Safety and Applied Nutrition (HFS-200), 5100 Paint Branch Pkwy., College
Park, MD 20740, or may be examined 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.\3\ As determined on appropriately shaped test samples of the article or acrylonitrile copolymer layer in a
multilayer construction by ASTM method D-1434-82, ``Standard Method for Determining Gas Permeability
Characteristics of Plastic Film and Sheeting,'' which is incorporated by reference. Copies are available from
the Center for Food Safety and Applied Nutrition (HFS-200), 5100 Paint Branch Pkwy., College Park, MD 20740,
and the American Society for Testing Materials, 100 Barr Harbor Dr., West Conshohocken, Philadelphia, PA 19428-
2959, or may be examined 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) Interim listing. Acrylonitrile copolymers identified in this section shall comply with the provisions of Sec. 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]