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177.1330 Ionomeric resins.

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[Code of Federal Regulations]
[Title 21, Volume 3]
[Revised as of April 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR177.1330]

[Page 260-264]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                          SERVICES (CONTINUED)
 
PART 177_INDIRECT FOOD ADDITIVES: POLYMERS--Table of Contents
 
Subpart B_Substances for Use as Basic Components of Single and Repeated 
                        Use Food Contact Surfaces
 
Sec.  177.1330  Ionomeric resins.

    Ionomeric resins manufactured from either ethylene-methacrylic acid 
copolymers (and/or their ammonium, calcium, magnesium, potassium, 
sodium, and/or zinc partial salts), ethylene-methacrylic acid-vinyl 
acetate copolymers (and/or their ammonium, calcium, magnesium, 
potassium, sodium, and/or zinc partial salts,), or methacrylic acid 
polymers with ethylene and isobutyl acrylate (and/or their potassium, 
sodium and/or zinc partial salts) may be safely used as articles or 
components of articles intended for use in contact with food, in 
accordance with the following prescribed conditions:
    (a) For the purpose of this section, the ethylene-methacrylic acid 
copolymers consist of basic copolymers produced by the copolymerization 
of ethylene and methacrylic acid such that the copolymers contain no 
more than 20 weight percent of polymer units derived from methacrylic 
acid, and the ethylene-methacrylic acid-vinyl acetate copolymers consist 
of basic copolymers produced by the copolymerization of ethylene, 
methacrylic acid, and vinyl acetate such that the copolymers contain no 
more than 15 weight percent of polymer units derived from methacrylic 
acid.
    (b) For the purpose of this section, the methacrylic acid copolymers 
with ethylene and isobutyl acrylate consist of basic copolymers produced 
by the copolymerization of methacrylic acid,

[[Page 261]]

ethylene, and isobutyl acrylate such that the copolymers contain no less 
than 70 weight percent of polymer units derived from ethylene, no more 
than 15 weight percent of polymer units derived from methacrylic acid, 
and no more than 20 weight percent of polymer units derived from 
isobutyl acrylate. From 20 percent to 70 percent of the carboxylic acid 
groups may optionally be neutralized to form sodium or zinc salts.
    (c) The finished food-contact article described in paragraph (a) of 
this section, when extracted with the solvent or solvents characterizing 
the type of food and under the conditions of time and temperature 
characterizing the conditions of its intended use as determined from 
tables 1 and 2 of Sec.  176.170(c) of this chapter, yields net acidified 
chloroform-soluble extractives in each extracting solvent not to exceed 
0.5 milligram per square inch of food-contact surface when tested by the 
methods described in paragraph (e)(1) of this section, and if the 
finished food-contact article is itself the subject of a regulation in 
parts 174, 175, 176, 177, 178 and Sec.  179.45 of this chapter, it shall 
also comply with any specifications and limitations prescribed for it by 
that regulation.
    Note: In testing the finished food-contact article, use a separate 
test sample for each required extracting solvent.
    (d) The finished food-contact article described in paragraph (b) of 
this section, when extracted according to the methods listed in 
paragraph (e)(2) of this section and referenced in this paragraph (d), 
using the solvent or solvents characterizing the type of food as 
determined from table I of paragraph (f) of this section, shall yield 
net acidified chloroform-soluble extractives as follows:
    (1) For fatty food use. (i) For films of 2 mil (0.002 inches) 
thickness or less, extractives shall not exceed 0.70 milligram/square 
inch \1\ (0.109 milligram/square centimeter) of food-contact surface (n-
heptane extractions) when extracted by the abbreviated method cited in 
paragraph (e)(2)(i) of this section.
---------------------------------------------------------------------------

    \1\ Average of four separate values, no single value of which 
differs from the average of those values by more then 10 percent.
---------------------------------------------------------------------------

    (ii) For films of greater than 2 mils (0.002 inch) thickness, 
extractives shall not exceed 0.40 milligram/square inch \1\ (0.062 
milligram/square centimeter) of food-contact surface (n-heptane 
extractions) when extracted by the abbreviated method cited in paragraph 
(e)(2)(i) of this section, or
    (iii) Alternatively, for films of greater than 2 mils thickness, 
extractives shall not exceed 0.70 milligram/square inch \1\ (0.109 
milligram/square centimeter) of food-contact surface (n-heptane 
extractions) when extracted by the equilibrium method cited in paragraph 
(e)(2)(ii) of this section.
    (2) For aqueous foods. (i) The net acidified chloroform-soluble 
extractives shall not exceed 0.02 milligram/square inch \2\(0.003 
milligram/square centimeter) of food-contact surface (water, acetic 
acid, or ethanol/water extractions) when extracted by the abbreviated 
method cited in paragraph (e)(2)(i) of this section.
---------------------------------------------------------------------------

    \2\ Average of four separate values, no single value of which 
differs from the average of those values by more than 50 percent.
---------------------------------------------------------------------------

    (ii) Alternatively, the net acidified chloroform-soluble extractives 
shall not exceed 0.05 milligram/square inch \3\ (0.078 mg/square 
centimeter) of food-contact surface (water, acetic acid, or ethanol/
water extractions) when extracted by the equilibrium method cited in 
paragraph (e)(2)(ii) of this section. If when exposed to n-heptane, a 
particular film splits along die lines, thus permitting exposure of both 
sides of the film to the extracting solvent, the results for that film 
sample are invalid and the test must be repeated for that sample until 
no splitting by the solvent occurs. If the finished food-contact article 
is itself the subject of a regulation in parts 174, 175, 176, 177, 178 
and Sec.  179.45 of this chapter, it shall also comply with any 
specifications and limitations prescribed for it by that regulation.
---------------------------------------------------------------------------

    \3\See footnote 2 to paragraph (d)(2)(i) of this section.
---------------------------------------------------------------------------

    Note: In testing the finished food-contact article, use a separate 
test sample for each required extracting solvent.

[[Page 262]]

    (e) Analytical methods--(1) Selection of extractability conditions 
for ionomeric resins. First ascertain the type of food (table 1 of Sec.  
176.170(c) of this chapter) that is being packed or used in contact with 
the finished food-contact article described in paragraph (a) of this 
section, and also ascertain the normal conditions of thermal treatment 
used in packaging or contacting the type of food involved. Using table 2 
of Sec.  176.170 (c) of this chapter, select the food-simulating solvent 
or solvents and the time-temperature test conditions that correspond to 
the intended use of the finished food-contact article. Having selected 
the appropriate food-simulating solvent or solvents and time-temperature 
exaggeration over normal use, follow the applicable extraction 
procedure.
    (2) Selection of extractability conditions for ionomeric resins. 
Using table I of paragraph (f) of this section ascertain the type of 
food that is being packed or used in contact with the finished food-
contact article described in paragraph (b) of this section, and also 
ascertain the food-simulating solvent or solvents that correspond to the 
intended use of the finished food-contact article.
    (i) Abbreviated test. For intended use involving food contact at or 
below 120 [deg]F (49 [deg]C), the appropriate food-simulating solvent is 
to contact the food-contact film for the time and temperatures as 
follows:

------------------------------------------------------------------------
               Solvent                   Time          Temperature
------------------------------------------------------------------------
n-Heptane............................    \1\ 2  120 [deg]F (49 [deg]C).
Water, 3% acetic acid, or 8%/50%        \1\ 48  120 [deg]F (49 [deg]C).
 ethanol.
------------------------------------------------------------------------
\1\ Hours

    (ii) Equilibrium test. For intended use involving food contact at or 
below 120 [deg]F (49 [deg]C), the appropriate food-simulating solvent is 
to contact the food-contact film at a temperature of 120 [deg]F until 
equilibrium is demonstrated.

------------------------------------------------------------------------
                                                                Minimum
                                                              extraction
                           Solvent                               times
                                                                (hours)
------------------------------------------------------------------------
n-Heptane...................................................   8, 10, 12
Water, 3% acetic acid, or 8%/50% ethanol....................     72, 96,
                                                                     120
------------------------------------------------------------------------


The results from a series of extraction times demonstrate equilibrium 
when the net chloroform-soluble extractives are unchanging within 
experimental error appropriate to the method as described in paragraphs 
(d) (1)(i) and (2)(i) of this section. Should equilibrium not be 
demonstrated over the above time series, extraction times must be 
extended until three successive unchanging values for extractives are 
obtained. In the case where intended uses involve temporary food contact 
above 120 [deg]F, the food-simulating solvent is to be contacted with 
the food-contact article under conditions of time and temperature that 
duplicate the actual conditions in the intended use. Subsequently the 
extraction is to be continued for the time period and under the 
conditions specified in the above table.
    (3) Reagents--(i) Water. All water used in extraction procedures 
should be freshly demineralized (deionized) distilled water.
    (ii) n-Heptane. Reagent grade, freshly redistilled before use, using 
only material boiling at 208 [deg]F (97.8 [deg]C).
    (iii) Alcohol. 8 or 50 percent (by volume), prepared from 
undenatured 95 percent ethyl alcohol diluted with demineralized 
(deionized), distilled water.
    (iv) Chloroform. Reagent grade, freshly redistilled before use, or a 
grade having an established, consistently low blank.
    (v) Acetic acid. 3 percent (by weight), prepared from glacial acetic 
acid diluted with demineralized (deionized), distilled water.
    (4) Selection of test method. The finished food-contact articles 
shall be tested either by the extraction cell described in the Journal 
of the Association of Official Agricultural Chemists, Vol. 47, No. 1, p. 
177-179 (February 1964), also described in ASTM method F34-76 
(Reapproved 1980), ``Standard Test Method for Liquid Extraction of 
Flexible Barrier Materials,'' which are incorporated by reference, or by 
adapting the in-container methods described in Sec.  175.300(e) of this 
chapter. Copies of the material incorporated by reference 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, and the American Society for Testing Materials, 100 Barr Harbor 
Dr., West

[[Page 263]]

Conshohocken, Philadelphia, PA 19428-2959, respectively, 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.
    (5) Selection of samples. Quadruplicate samples should be tested, 
using for each replicate sample the number of finished articles with a 
food-contact surface nearest to 100 square inches.
    (6) Determination of amount of extractives--(i) Total residues. At 
the end of the exposure period, remove the test container or test cell 
from the oven, if any, and combine the solvent for each replicate in a 
clean Pyrex (or equivalent) flask or beaker, being sure to rinse the 
test container or cell with a small quantity of clean solvent. Evaporate 
the food-simulating solvents to about 100 milliliters in the flask, and 
transfer to a clean, tared evaporating dish (platinum or Pyrex), washing 
the flask three times with small portions of solvent used in the 
extraction procedure, and evaporate to a few milliliters on a 
nonsparking, low-temperature hotplate. The last few milliliters should 
be evaporated in an oven maintained at a temperature of 221 [deg]F (105 
[deg]C). Cool the evaporating dish in a desiccator for 30 minutes and 
weigh the residues to the nearest 0.1 milligram, e. Calculate the 
extractives in milligrams per square inch of the container or material 
surface.
    (a) Water, 3 percent acetic acid, and 8 percent and 50 percent 
alcohol. Milligrams extractives per square inch=e/s.
    (b) Heptane. Milligrams extractives per square inch=(e)/(s)(F)

where:

e=Milligrams extractives per sample tested.
s=Surface area tested, in square inches.
F=Five, the ratio of the amount of extractives removed by heptane under 
exaggerated time-temperature test conditions compared to the amount 
extracted by a fat or oil under exaggerated conditions of thermal 
sterilization and use.
e'=Acidified chloroform-soluble extractives residue. e' is substituted 
for e in the above equations when necessary (See paragraph (e)(6)(ii) of 
this section for method to obtain e').


If when calculated by the equations in paragraphs (e)(6)(i) (a) and (b) 
of this section, the extractives in milligrams per square inch exceed 
the limitations prescribed in paragraphs (c) or (d) of this section, 
proceed to paragraph (e)(6)(ii) of this section (method for determining 
the amount of acidified chloroform-soluble extractives residue).
    (ii) Acidified chloroform-soluble extractives residue. Add 3 
milliliters of 37 percent ACS reagent grade hydrochloric acid and 3 
milliliters of distilled water to the evaporating dish containing the 
dried and weighed residue, e, obtained in paragraph (e)(6)(i) of this 
section. Mix well so every portion of the residue is wetted with the 
hydrochloric acid solution. Then add 50 milliliters of chloroform. Warm 
carefully, and filter through Whatman No. 41 filter paper (or 
equivalent) in a Pyrex (or equivalent) funnel, collecting the filtrate 
in a clean separatory funnel. Shake for 1 minute, then draw off the 
chloroform layer into a clean tared evaporating dish (platinum or 
Pyrex). Repeat the chloroform extraction, washing the dish, the filter 
paper, and the separatory funnel with this second portion of chloroform. 
Add this filtrate to the original filtrate and evaporate the total down 
to a few milliliters on a low-temperature hotplate. The last few 
milliliters should be evaporated in an oven maintained at 221 [deg]F. 
Cool the evaporating dish in a desiccator for 30 minutes and weigh to 
the nearest 0.1 milligram to get the acidified chloroform-soluble 
extractives residue, e'. This e' is substituted for e in the equations 
in paragraphs (e)(6)(i) (a) and (b) of this section.
    (f) The types of food and appropriate solvents are as follows:

                                 Table 1
------------------------------------------------------------------------
             Types of food                     Appropriate solvent
------------------------------------------------------------------------
1. Nonacid (pH above 5.0), aqueous      Water, n-heptane.
 products; may contain salt or sugar
 or both, and including oil-in-water
 emulsions of low- or high-fat content.
2. Acidic (pH 5.0 or below), aqueous    n-heptane, water, 3% acetic
 products; may contain salt or sugar     acid.
 or both, and including oil-in-water
 emulsions of low- or high-fat content.

[[Page 264]]


3. Aqueous, acid or nonacid products    Water, n-heptane, 3% acetic
 containing free oil or fat; may         acid.
 contain salt, and including water-in-
 oil emulsions of low- or high-fat
 content.
4. Dairy products and modifications:
  Water, n-heptane....................
  i. Water-in-oil emulsions, high or
   low fat.
  ii. Oil-in-water emulsions, high or
   low fat.
5. Low moisture fats and oils.........  n-heptane.
6. Beverages:
  i. Containing up to 8% alcohol......  8% ethanol/water.
  ii. Nonalcoholic....................  3% acetic acid.
  iii. Containing more than 8% alcohol  50% ethanol/water.
7. Bakery products....................  Water, n-heptane.
8. Dry solids (without free fat or      No extraction test required.
 oil).
9. Dry solids (with free fat or oil)..  n-heptane.
------------------------------------------------------------------------

    (g) The provisions of paragraphs (c) and (d) of this section are not 
applicable to the ionomeric resins that are used in food-packaging 
adhesives complying with Sec.  175.105 of this chapter.

[45 FR 22916, Apr. 4, 1980, as amended at 49 FR 10108, Mar. 19, 1984; 49 
FR 37747, Sept. 26, 1984; 53 FR 44009, Nov. 1, 1988; 54 FR 24898, June 
12, 1989]





Additives that reference this regulation:


Source: U.S. Code of Federal Regulations - CFR Title 21, Part 177, Section 1330


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