[Code of Federal Regulations]
[Title 21, Volume 3]
[Revised as of April 1, 2001]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR177.1010]
[Page 222-228]
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. 177.1010 Acrylic and modified acrylic plastics, semirigid and rigid.
Semirigid and rigid acrylic and modified acrylic plastics may be
safely used as articles intended for use in contact
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with food, in accordance with the following prescribed conditions. The
acrylic and modified acrylic polymers or plastics described in this
section also may be safely used as components of articles intended for
use in contact with food.
(a) The optional substances that may be used in the formulation of
the semirigid and rigid acrylic and modified acrylic plastics, or in the
formulation of acrylic and modified acrylic components of articles,
include substances generally recognized as safe in food, substances used
in accordance with a prior sanction or approval, substances permitted
for use in such plastics by regulations in parts 170 through 189 of this
chapter, and substances identified in this paragraph. At least 50
weight-percent of the polymer content of the acrylic and modified
acrylic materials used as finished articles or as components of articles
shall consist of polymer units derived from one or more of the acrylic
or methacrylic monomers listed in paragraph (a)(1) of this section.
(1) Homopolymers and copolymers of the following monomers:
n-Butyl acrylate.
n-Butyl methacrylate.
Ethyl acrylate.
2-Ethylhexyl acrylate.
Ethyl methacrylate.
Methyl acrylate.
Methyl methacrylate.
(2) Copolymers produced by copolymerizing one or more of the
monomers listed in paragraph (a)(1) of this section with one or more of
the following monomers:
Acrylonitrile.
Methacrylonitrile.
-Methylstyrene.
Styrene.
Vinyl chloride.
Vinylidene chloride.
(3) Polymers identified in paragraphs (a)(1) and (2) of this section
containing no more than 5 weight-percent of total polymer units derived
by copolymerization with one or more of the monomers listed in paragraph
(a)(3)(i) and (ii) of this section. Monomers listed in paragraph
(a)(3)(ii) of this section are limited to use only in plastic articles
intended for repeated use in contact with food.
(i) List of minor monomers:
Acrylamide.
Acrylic acid
1,3-Butylene glycol dimethacrylate.
1,4-Butylene glycol dimethacrylate.
Diethylene glycol dimethacrylate.
Diproplylene glycol dimethacrylate.
Divinylbenzene.
Ethylene glycol dimethacrylate.
Itaconic acid.
Methacrylic acid.
N-Methylolacrylamide.
N-Methylolmethacrylamide.
4-Methyl-1,4-pentanediol dimethacrylate.
Propylene glycol dimethacrylate.
Trivinylbenzene.
(ii) List of minor monomers limited to use only in plastic articles
intended for repeated use in contact with food:
Allyl methacrylate [Chemical Abstracts Service Registry No. 96-05-9]
tert-Butyl acrylate.
tert-Butylaminoethyl methacrylate.
sec-Butyl methacrylate.
tert-Butyl methacrylate.
Cyclohexyl methacrylate.
Dimethylaminoethyl methacrylate.
2-Ethylhexyl methacrylate.
Hydroxyethyl methacrylate.
Hydroxyethyl vinyl sulfide.
Hydroxypropyl methacrylate.
Isobornyl methacrylate.
Isobutyl methacrylate.
Isopropyl acrylate.
Isopropyl methacrylate.
Methacrylamide.
Methacrylamidoethylene urea.
Methacryloxyacetamidoethylethylene urea.
Methacryloxyacetic acid.
n-Propyl methacrylate.
3,5,5-Trimethylcyclohexyl methacrylate.
(4) Polymers identified in paragraphs (a)(1), (2), and (3) of this
section are mixed together and/or with the following polymers, provided
that no chemical reactions, other than addition reactions, occur when
they are mixed:
Butadiene-acrylonitrile copolymers.
Butadiene-acrylonitrile-styrene copolymers.
Butadiene-acrylonitrile-styrene-methyl methacrylic copolymers.
Butadiene-styrene copolymers.
Butyl rubber.
Natural rubber.
Polybutadiene.
Poly (3-chloro-1,3-butadiene).
Polyester identified in Sec. 175.300(b)(3)(vii) of this chapter.
Polyvinyl chloride.
Vinyl chloride copolymers complying with Sec. 177.1980.
Vinyl chloride-vinyl acetate copolymers.
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(5) Antioxidants and stabilizers identified in
Sec. 175.300(b)(3)(xxx) of this chapter and the following:
Di-tert-butyl-p-cresol.
2-Hydroxy-4-methoxybenzophenone.
2-Hydroxy-4-methoxy-2-carboxybenzophenone.
3-Hydroxyphenyl benzoate.
p-Methoxyphenol.
Methyl salicylate.
Octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate (CAS Reg. No. 2082-
79-3): For use only: (1) At levels not exceeding 0.2 percent by weight
in semirigid and rigid acrylic and modified acrylic plastics, where the
finished articles contact foods containing not more than 15 percent
alcohol; and (2) at levels not exceeding 0.01 percent by weight in
semirigid and rigid acrylic and modified acrylic plastics intended for
repeated food-contact use where the finished article may be used for
foods containing more than 15 percent alcohol.
Phenyl salicylate.
(6) Release agents: Fatty acids derived from animal and vegetable
fats and oils, and fatty alcohols derived from such acids.
(7) Surface active agent: Sodium dodecylbenzenesulfonate.
(8) Miscellaneous materials:
Di(2-ethylhexyl) phthalate, for use only as a flow promoter at a level
not to exceed 3 weight-percent based on the monomers.
Dimethyl phthalate.
Oxalic acid, for use only as a polymerization catalyst aid.
Tetraethylenepentamine, for use only as a catalyst activator at a level
not to exceed 0.5 weight-percent based on the monomers.
Toluene.
Xylene.
(b) The semirigid and rigid acrylic and modified acrylic plastics,
in the finished form in which they are to contact food, when extracted
with the solvent or solvents characterizing the type of food and under
the conditions of time and temperature as determined from tables 1 and 2
of Sec. 176.170(c) of this chapter, shall yield extractives not to
exceed the following, when tested by the methods prescribed in paragraph
(c) of this section. The acrylic and modified acrylic polymers or
plastics intended to be used as components of articles also shall yield
extractives not to exceed the following limitations when prepared as
strips as described in paragraph (c)(2) of this section:
(1) Total nonvolatile extractives not to exceed 0.3 milligram per
square inch of surface tested.
(2) Potassium permanganate oxidizable distilled water and 8 and 50
percent alcohol extractives not to exceed an absorbance of 0.15.
(3) Ultraviolet-absorbing distilled water and 8 and 50 percent
alcohol extractives not to exceed an absorbance of 0.30.
(4) Ultraviolet-absorbing n-heptane extractives not to exceed an
absorbance of 0.10.
(c) Analytical methods--(1) Selection of extractability conditions.
These are to be chosen as provided in Sec. 176.170(c) of this chapter.
(2) Preparation of samples. Sufficient samples to allow duplicates
of all applicable tests shall be cut from the articles or formed from
the plastic composition under tests, as strips about 2.5 inches by about
0.85-inch wide by about 0.125-inch thick. The total exposed surface
should be 5 square inches plus-minus0.5-square inch. The
samples, after preparation, shall be washed with a clean brush under hot
tapwater, rinsed under running hot tapwater (140 deg.F minimum), rinsed
with distilled water, and air-dried in a dust-free area or in a
desiccator.
(3) Preparation of solvents. The water used shall be double-
distilled water, prepared in a still using a block tin condenser. The 8
and 50 percent (by volume) alcohol solvents shall be prepared from ethyl
alcohol meeting the specifications of the United States Pharmacopeia XX
and diluted with double-distilled water that has been prepared in a
still using a tin block condenser. The n-heptane shall be
spectrophotometric grade. Adequate precautions must be taken to keep all
solvents dust-free.
(4) Blank values on solvents. (i) Duplicate determinations of
residual solids shall be run on samples of each solvent that have been
exposed to the temperature-time conditions of the extraction test
without the plastic sample. Sixty milliliters of exposed solvent is
pipetted into a clean, weighed platinum dish, evaporated to 2-5
milliliters on a nonsparking, low-temperature hot plate and dried in 212
deg.F oven for 30 minutes. The residue for each solvent shall be
determined by weight and the
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average residue weight used as the blank value in the total solids
determination set out in paragraph (c)(6) of this section. The residue
for an acceptable solvent sample shall not exceed 0.5 milligram per 60
milliliters.
(ii) For acceptability in the ultraviolet absorbers test, a sample
of each solvent shall be scanned in an ultraviolet spectrophotometer in
5-centimeter silica spectrophotometric absorption cells. The absorbance
of the distilled water when measured versus air in the reference cell
shall not exceed 0.03 at any point in the wavelength region of 245 to
310 m. The absorbance of the 8 percent alcohol when measured
versus distilled water in the reference cell shall not exceed 0.01 at
any point in the wavelength region of 245 to 310 m. The
absorbance of the 50 percent alcohol when measured versus distilled
water in the reference cell shall not exceed 0.05 at any point in the
wavelength region of 245 to 310 m. The absorbance of the
heptane when measured versus distilled water in the reference cell shall
not exceed 0.15 at 245, 0.09 at 260, 0.04 at 270, and 0.02 at any point
in the wavelength region of 280 to 310 m.
(iii) Duplicate ultraviolet blank determinations shall be run on
samples of each solvent that has been exposed to the temperature-time
conditions of the extraction test without the plastic sample. An aliquot
of the exposed solvent shall be measured versus the unexposed solvent in
the reference cell. The average difference in the absorbances at any
wavelength in the region of 245 to 310 m shall be used as a
blank correction for the ultraviolet absorbers measured at the same
wavelength according to paragraph (c)(8)(ii) of this section.
(iv) The acceptability of the solvents for use in the permanganate
test shall be determined by preparing duplicate permanganate test blanks
according to paragraph (c)(7)(iv) of this section. For this test, the
directions referring to the sample extract shall be disregarded. The
blanks shall be scanned in 5-centimeter silica spectrophotometric cells
in the spectrophotometer versus the appropriate solvent as reference.
The absorbance in distilled water in the wavelength region of 544 to 552
m should be 1.16 but must not be less than 1.05 nor more than
1.25. The absorbance in the 8 and 50 percent alcohol must not be less
than 0.85 nor more than 1.15.
(v) Duplicate permanganate test determinations shall be run on
samples of distilled water and 8 and 50 percent alcohol solvents that
have been exposed to the temperature-time conditions of the extraction
test without the plastic sample. The procedure shall be as described in
paragraph (c)(7)(iv) of this section, except that the appropriate
exposed solvent shall be substituted where the directions call for
sample extract. The average difference in the absorbances in the region
of 544 to 552 m shall be used as a blank correction for the
determination of permanganate oxidizable extractives according to
paragraph (c)(7)(iv) of this section.
(5) Extraction procedure. For each extraction, place a plastic
sample in a clean 25 millimeters x 200 millimeters hard-glass test
tube and add solvent equal to 10 milliliters of solvent per square inch
of plastic surface. This amount will be between 45 milliliters and 55
milliliters. The solvent must be preequilibrated to the temperature of
the extraction test. Close the test tube with a ground-glass stopper and
expose to the specified temperature for the specified time. Cool the
tube and contents to room temperature if necessary.
(6) Determination of total nonvolatile extractives. Remove the
plastic strip from the solvent with a pair of clean forceps and wash the
strip with 5 milliliters of the appropriate solvent, adding the washings
to the contents of the test tube. Pour the contents of the test tube
into a clean, weighed platinum dish. Wash the tube with 5 milliliters of
the appropriate solvent and add the solvent to the platinum dish.
Evaporate the solvent to 2-5 milliliters on a nonsparking, low-
temperature hotplate. Complete the evaporation in a 212 deg.F oven for
30 minutes. Cool the dish in a desiccator for 30 minutes and weigh to
the nearest 0.1 milligram. Calculate the total nonvolatile extractives
as follows:
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[GRAPHIC] [TIFF OMITTED] TR01JA93.392
[GRAPHIC] [TIFF OMITTED] TR01JA93.393
where:
e=Total increase in weight of the dish, in milligrams.
b=Blank value of the solvent in milligrams, as determined in paragraph
(c)(4)(i) of this section.
s=Total surface of the plastic sample in square inches.
(7) Determination of potassium permanganate oxidizable extractives.
(i) Pipette 25 milliliters of distilled water into a clean 125-
milliliter Erlenmeyer flask that has been rinsed several times with
aliquots of distilled water. This is the blank. Prepare a distilled
water solution containing 1.0 part per million of p-methoxyphenol
(melting point 54-56 deg.C, Eastman grade or equivalent). Pipette 25
milliliters of this p-methoxyphenol solution into a rinsed Erlenmeyer
flask. Pipette exactly 3.0 milliliters of 154 parts per million aqueous
potassium permanganate solution into the p-methoxyphenol and exactly 3.0
milliliters into the blank, in that order. Swirl both flasks to mix the
contents and then transfer aliquots from each flask into matched 5-
centimeter spectrophotometric absorption cells. The cells are placed in
the spectrophotometer cell compartment with the p-methoxyphenol solution
in the reference beam. Spectrophotometric measurement is conducted as in
paragraph (c)(7)(iv) of this section. The absorbance reading in the
region 544-552 m should be 0.24 but must be not less than 0.12
nor more than 0.36. This test shall be run in duplicate. For the purpose
of ascertaining compliance with the limitations in paragraph (b)(2) of
this section, the absorbance measurements obtained on the distilled
water extracts according to paragraph (c)(7)(iv) of this section shall
be multiplied by a correction factor, calculated as follows:
[GRAPHIC] [TIFF OMITTED] TR01JA93.394
(ii) The procedure in paragraph (c)(7)(i) of this section is
repeated except that, in this instance, the solvent shall be 8 percent
alcohol. The absorbance in the region 544-552 m should be 0.26
but must be not less than 0.13 nor more than 0.39. This test shall be
run in duplicate. For the purpose of ascertaining compliance with the
limitations prescribed in paragraph (b)(2) of this section, the
absorbance measurements obtained on the 8 percent alcohol extracts
according to paragraph (c)(7)(iv) of this section shall be multiplied by
a correction factor, calculated as follows:
[GRAPHIC] [TIFF OMITTED] TR01JA93.395
(iii) The procedure in paragraph (c)(7)(i) of this section is
repeated except that, in this instance, the solvent shall be 50 percent
alcohol. The absorbance in the region 544-552 m should be 0.25
but must be not less than 0.12 nor more than 0.38. This test shall be
run in duplicate. For the purpose of
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ascertaining compliance with the limitations prescribed in paragraph
(b)(2) of this section, the absorbance measurements obtained on the 50
percent alcohol extracts according to paragraph (c)(7)(iv) of this
section shall be multiplied by a correction factor, calculated as
follows:
[GRAPHIC] [TIFF OMITTED] TR01JA93.396
(iv) Water and 8 and 50 percent alcohol extracts. Pipette 25
milliliters of the appropriate solvent into a clean, 125-milliliter
Erlenmeyer flask that has been rinsed several times with aliquots of the
same solvent. This is the blank. Into another similarly rinsed flask,
pipette 25 milliliters of the sample extract that has been exposed under
the conditions specified in paragraph (c)(5) of this section. Pipette
exactly 3.0 milliliters of 154 parts per million aqueous potassium
permanganate solution into the sample and exactly 3.0 milliliters into
the blank, in that order. Before use, the potassium permanganate
solution shall be checked as in paragraph (c)(7)(i) of this section.
Both flasks are swirled to mix the contents, and then aliquots from each
flask are transferred to matched 5-centimeter spectrophotometric
absorption cells. Both cells are placed in the spectrophotometer cell
compartment with the sample solution in the reference beam. The
spectrophotometer is adjusted for 0 and 100 percent transmittance at 700
m. The spectrum is scanned on the absorbance scale from 700
m to 500 m in such a way that the region 544
m to 552 m is scanned within 5 minutes to 10 minutes
of the time that permanganate was added to the solutions. The height of
the absorbance peak shall be measured, corrected for the blank as
determined in paragraph (c)(4)(v) of this section, and multiplied by the
appropriate correction factor determined according to paragraph (c)(7)
(i), (ii), and (iii) of this section. This test shall be run in
duplicate and the two results averaged.
(8) Determination of ultraviolet-absorbing extractives. (i) A
distilled water solution containing 1.0 part per million of p-
methoxyphenol (melting point 54 deg.C-56 deg.C. Eastman grade or
equivalent) shall be scanned in the region 360 to 220 m in 5-
centimeter silica spectrophotometric absorption cells versus a distilled
water reference. The absorbance at the wavelength of maximum absorbance
(should be about 285 m) is about 0.11 but must be not less than
0.08 nor more than 0.14. This test shall be run in duplicate. For the
purpose of ascertaining compliance with the limitations prescribed in
paragraph (b) (3) and (4) of this section, the absorbance obtained on
the extracts according to paragraph (c)(8)(ii) of this section shall be
multiplied by a correction factor, calculated as follows:
[GRAPHIC] [TIFF OMITTED] TR01JA93.397
(ii) An aliquot of the extract that has been exposed under the
conditions specified in paragraph (c)(5) of this section is scanned in
the wavelength region 360 to 220 m versus the appropriate
solvent reference in matched 5-
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centimeter silica spectrophotometric absorption cells. The height of any
absorption peak shall be measured, corrected for the blank as determined
in paragraph (c)(4)(iii) of this section, and multiplied by the
correction factor determined according to paragraph (c)(8)(i) of this
section.
(d) In accordance with current good manufacturing practice, finished
semirigid and rigid acrylic and modified acrylic plastics, and articles
containing these polymers, intended for repeated use in contact with
food shall be thoroughly cleansed prior to their first use in contact
with food.
(e) Acrylonitrile copolymers identified in this section shall comply
with the provisions of Sec. 180.22 of this chapter.
(f) The acrylic and modified acrylic polymers identified in and
complying with this section, when used as components of the food-contact
surface of an article that is the subject of a regulation in this part
and in parts 174, 175, 176, and 178 of this chapter, shall comply with
any specifications and limitations prescribed by such regulation for the
article in the finished form in which it is to contact food.
[42 FR 14572, Mar. 15, 1977; 42 FR 56728, Oct. 28, 1977, as amended at
43 FR 54927, Nov. 24, 1978; 45 FR 67320, Oct. 10, 1980; 46 FR 46796,
Sept. 22, 1981; 49 FR 10108, Mar. 19, 1984; 49 FR 13139, Apr. 3, 1984;
50 FR 31045, July 24, 1985]