[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,
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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.
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\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.
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\3\See footnote 2 to paragraph (d)(2)(i) of this section.
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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
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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: |
