[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: 21CFR172.864]
[Page 101-105]
TITLE 21--FOOD AND DRUGS
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
SERVICES (CONTINUED)
PART 172_FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN
CONSUMPTION--Table of Contents
Subpart I_Multipurpose Additives
Sec. 172.864 Synthetic fatty alcohols.
Synthetic fatty alcohols may be safely used in food and in the
synthesis of food components in accordance with the following prescribed
conditions:
[[Page 102]]
(a) The food additive consists of any one of the following fatty
alcohols:
(1) Hexyl, octyl, decyl, lauryl, myristyl, cetyl, and stearyl;
manufactured by fractional distillation of alcohols obtained by a
sequence of oxidation and hydrolysis of organo-aluminums generated by
the controlled reaction of low molecular weight trialkylaluminum with
purified ethylene (minimum 99 percent by volume
C2H4), and utilizing the hydrocarbon solvent as
defined in paragraph (b) of this section, such that:
(i) Hexyl, octyl, decyl, lauryl, and myristyl alcohols contain not
less than 99 percent of total alcohols and not less than 96 percent of
straight chain alcohols. Any nonalcoholic impurities are primarily
paraffins.
(ii) Cetyl and stearyl alcohols contain not less than 98 percent of
total alcohols and not less than 94 percent of straight chain alcohols.
Any nonalcoholic impurities are primarily paraffins.
(iii) The synthetic fatty alcohols contain no more than 0.1 weight
percent of total diols as determined by a method available upon request
from the Commissioner of Food and Drugs.
(2) Hexyl, octyl, and decyl; manufactured by fractional distillation
of alcohols obtained by a sequence of oxidation, hydrolysis, and
catalytic hydrogenation (catalyst consists of copper, chromium, and
nickel) of organo-aluminums generated by the controlled reaction of low
molecular weight trialkylaluminum with purified ethylene (minimum 99
percent by volume C2H4), and utilizing an external
coolant such that these alcohols meet the specifications prescribed in
paragraph (a)(1) (i) and (iii) of this section.
(3) n-Octyl; manufactured by the hydrodimerization of 1,3-butadiene,
followed by catalytic hydrogenation of the resulting dienol, and
distillation to produce n-octyl alcohol with a minimum purity of 99
percent. The analytical method for n-octyl alcohol entitled ``Test
Method [Normal-octanol]'' dated October 2003, and printed by Kuraray
Co., Ltd., is incorporated by reference. The Director of the Office of
the Federal Register approves this incorporation by reference in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain a copy
from the Office of Food Additive Safety, 5100 Paint Branch Pkwy.,
College Park, MD 20740, or you may examine a copy at the Center for Food
Safety and Applied Nutrition's Library, Food and Drug Administration,
5100 Paint Branch Pkwy., College Park, MD 20740, or 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.
(b) The hydrocarbon solvent used in the process described in
paragraph (a)(1) of this section is a mixture of liquid hydrocarbons
essentially paraffinic in nature, derived from petroleum and refined to
meet the specifications described in paragraph (b)(1) of this section
when subjected to the procedures described in paragraph (b) (2) and (3)
of this section.
(1) The hydrocarbon solvent meets the following specifications:
(i) Boiling-point range: 175 [deg]C-275 [deg]C.
(ii) Ultraviolet absorbance limits as follows:
------------------------------------------------------------------------
Maximum
absorbance
per
Wavelength (millicrons) centimeter
optical
path
length
------------------------------------------------------------------------
280-289..................................................... 0.15
290-299..................................................... .12
300-359..................................................... .05
360-400..................................................... .02
------------------------------------------------------------------------
(2) Use ASTM method D86-82, ``Standard Method for Distillation of
Petroleum Products,'' which is incorporated by reference, to determine
boiling point range. Copies of the material incorporated by reference
may be obtained from 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.
(3) The analytical method for determining ultraviolet absorbance
limits is as follows:
[[Page 103]]
General Instructions
All glassware should be scrupulously cleaned to remove all organic
matter such as oil, grease, detergent residues, etc. Examine all
glassware, including stoppers and stopcocks, under ultraviolet light to
detect any residual fluorescent contamination. As a precautionary
measure, it is recommended practice to rinse all glassware with purified
isooctane immediately before use. No grease is to be used on stopcocks
or joints. Great care to avoid contamination of hydrocarbon solvent
samples in handling and to assure absence of any extraneous material
arising from inadequate packaging is essential. Because some of the
polynuclear hydrocarbons sought in this test are very susceptible to
photo-oxidation, the entire procedure is to be carried out under subdued
light.
Apparatus
Chromatographic tube. 450 millimeters in length (packing section),
inside diameter 19 millimeters 1 millimeter,
equipped with a wad of clean Pyrex brand filtering wool (Corning Glass
Works Catalog No. 3950 or equivalent). The tube shall contain a 250-
milliliter reservoir and a 2-millimeter tetrafluoroethylene polymer
stopcock at the opposite end. Overall length of the tube is 670
millimeters.
Stainless steel rod. 2 feet in length, 2 to 4 millimeters in
diameter.
Vacuum oven. Similar to Labline No. 3610 but modified as follows: A
copper tube one-fourth inch in diameter and 13 inches in length is bent
to a right angle at the 4-inch point and plugged at the opposite end;
eight copper tubes one-eighth inch in diameter and 5 inches in length
are silver soldered in drilled holes (one-eighth inch in diameter) to
the one-fourth-inch tube, one on each side at the 5-, 7.5-, 10- and
12.5-inch points; the one-eighth-inch copper tubes are bent to conform
with the inner periphery of the oven.
Beakers. 250-milliliter and 500-milliliter capacity.
Graduated cylinders. 25-milliliter, 50-milliliter, and 150-
milliliter capacity.
Tuberculin syringe. 1-milliliter capacity, with 3-inch, 22-gauge
needle.
Volumetric flask. 5-milliliter capacity.
Spectrophotometric cells. Fused quartz ground glass stoppered cells,
optical path length in the range of 1.000 centimeter 0.005 centimeter. With distilled water in the cells,
determine any absorbance difference.
Spectrophotometer. Spectral range 250 millimicrons--400 millimicrons
with spectral slit width of 2 millimicrons or less: under instrument
operating conditions for these absorbance measurements, the
spectrophotometer shall also meet the following performance
requirements:
Absorbance repeatability, 0.01 at 0.4
absorbance.
Absorbance accuracy,\1\ 0.05 at 0.4
absorbance.
---------------------------------------------------------------------------
\1\ As determined by using potassium chromate for reference standard
and described in National Bureau of Standards Circular 484,
Spectrophotometry, U.S. Department of Commerce, (1949). The accuracy is
to be determined by comparison with the standard values at 290, 345, and
400 millimicrons. Circular 484 is incorporated by reference. Copies 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, 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.
---------------------------------------------------------------------------
Wavelength repeatability, 0.2 millimicron.
Wavelength accuracy, 1.0 millimicron.
Nitrogen cylinder. Water-pumped or equivalent purity nitrogen in
cylinder equipped with regulator and valve to control flow at 5 p.s.i.g.
Reagents and Materials
Organic solvents. All solvents used throughout the procedure shall
meet the specifications and tests described in this specification. The
isooctane, benzene, hexane, and 1,2-dichloroethane designated in the
list following this paragraph shall pass the following test:
To the specified quantity of solvent in a 250-milliliter beaker, add
1 milliliter of purified n-hexadecane and evaporate in the vacuum oven
under a stream of nitrogen. Discontinue evaporation when not over 1
milliliter of residue remains. (To the residue from benzene add a 5-
milliliter portion of purified isooctane, reevaporate, and repeat once
to insure complete removal of benzene.)
Dissolve the 1 milliliter of hexadecane residue in isooctane and
make to 5 milliliters volume. Determine the absorbance in the 1-
centimeter path length cells compared to isooctane as reference. The
absorbance of the solution of the solvent residue shall not exceed 0.02
per centimeter path length between 280 and 300 m[micro] and shall not
exceed 0.01 per centimeter path length between 300 and 400 m[micro].
Isooctane (2,2,4-trimethylpentane). Use 10 milliliters for the test
described in the preceding paragraph. If necessary, isooctane may be
purified by passage through a column of activated silica gel (Grade 12,
Davison Chemical Co., Baltimore, Md., or equivalent).
[[Page 104]]
Benzene, spectro grade (Burdick and Jackson Laboratories, Inc.,
Muskegon, Mich., or equivalent). Use 80 milliliters for the test. If
necessary, benzene may be purified by distillation or otherwise.
Hexane, spectro grade (Burdick and Jackson Laboratories, Inc.,
Muskegon, Mich., or equivalent). Use 650 milliliters for the test. If
necessary, hexane may be purified by distillation or otherwise.
1,2-Dichloroethane, spectro grade (Matheson, Coleman, and Bell, East
Rutherford, N.J., or equivalent). Use 20 milliliters for test. If
necessary, 1,2-dichloroethane may be purified by distillation.
Eluting mixtures:
1. 10 percent 1,2-dichloroethane in hexane. Pipet 100 milliliters of
1,2-dichloroethane into a 1-liter glass-stoppered volumetric flask and
adjust to volume with hexane, with mixing.
2. 40 percent benzene in hexane. Pipet 400 milliliters of benzene
into a 1-liter glass-stoppered volumetric flask and adjust to volume
with hexane, with mixing.
n-Hexadecane, 99 percent olefin-free. Dilute 1.0 milliliter of n-
hexadecane to 5 milliliters with isooctane and determine the absorbance
in a 1-centimeter cell compared to isooctane as reference between 280
m[micro]-400m[micro]. The absorbance per centimeter path length shall
not exceed 0.00 in this range. If necessary, n-hexadecane may be
purified by percolation through activated silica gel or by distillation.
Silica gel, 28-200 mesh (Grade 12, Davison Chemical Co., Baltimore,
Md., or equivalent). Activate as follows: Weigh about 900 grams into a
1-gallon bottle, add 100 milliliters of de-ionized water, seal the
bottle and shake and roll at intervals for 1 hour. Allow to equilibrate
overnight in the sealed bottle. Activate the gel at 150 [deg]C for 16
hours, in a 2-inch x 7-inch x 12-inch porcelain pan loosely covered with
aluminum foil, cool in a dessicator, transfer to a bottle and seal.
Procedure
Determination of ultraviolet absorbance. Before proceeding with the
analysis of a sample determine the absorbance in a 1-centimeter path
cell for the reagent blank by carrying out the procedure without a
sample. Record the absorbance in the wavelength range of 280 to 400
millimicrons. Typical reagent blank absorbance in this range should not
exceed 0.04 in the 280 to 299 millimicron range, 0.02 in the 300 to 359
millimicron range, and 0.01 in the 360 to 400 millimicron range. If the
characteristic benzene peaks in the 250 to 260 millimicron region are
present, remove the benzene by the procedure described above under
``Reagents and Materials,'' ``Organic Solvents,'' and record absorbance
again.
Transfer 50 grams of silica gel to the chromatographic tube for
sample analysis. Raise and drop the column on a semisoft, clean surface
for about 1 minute to settle the gel. Pour 100 milliliters of hexane
into the column with the stopcock open and allow to drain to about one-
half inch above the gel. Turn off the stopcock and allow the column to
cool for 30 minutes. After cooling, vibrate the column to eliminate air
and stir the top 1 to 2 inches with a small diameter stainless steel
rod. Take care not to get the gel above the liquid and onto the sides of
the column.
Weigh out 40 grams 0.1 gram of the hydrocarbon
solvent sample into a 250-milliliter beaker, add 50 milliliters of
hexane, and pour the solution into the column. Rinse the beaker with 50
milliliters of hexane and add this to the column. Allow the hexane
sample solution to elute into a 500-milliliter beaker until the solution
is about one-half inch above the gel. Rinse the column three times with
50-milliliter portions of hexane. Allow each hexane rinse to separately
elute to about one-half inch above the gel. Replace the eluate beaker
(discard the hexane eluate) with a 250-milliliter beaker. Add two
separate 25-milliliter portions of 10 percent 1,2-dichloroethane and
allow each to separately elute as before. Finally, add 150 milliliters
of 10 percent 1,2-dichloroethane for a total of 200 milliliters. When
the final 10 percent 1,2-dichloroethane fraction is about one-half inch
above the top of the gel bed, replace the receiving beaker (discard the
1,2-dichloroethane eluate) with a 250-milliliter beaker containing 1
milliliter of hexadecane. Adjust the elution rate to 2 to 3 milliliters
per minute, add two 25-milliliter portions of 40 percent benzene and
allow each to separately elute as before to within about one-half inch
of the gel bed. Finally, add 150 milliliters of 40 percent benzene for a
total of 200 milliliters. Evaporate the benzene in the oven with vacuum
and sufficient nitrogen flow to just ripple the top of the benzene
solution. When the benzene is removed (as determined by a constant
volume of hexadecane) add 5 milliliters of isooctane and evaporate.
Repeat once to insure complete removal of benzene. Remove the beaker and
cover with aluminum foil (previously rinsed with hexane) until cool.
Quantitatively transfer the hexadecane residue to a 5-milliliter
volumetric flask and dilute to volume with isooctane. Determine the
absorbance of the solution in 1-centimeter path length cells between 280
and 400 millimicrons using isooctane as a reference. Correct the
absorbance values for any absorbance derived from reagents as determined
by carrying out the procedure without a sample. If the corrected
absorbance does not exceed the limits prescribed in paragraph (b)(1)(ii)
of this section, the sample meets the ultraviolet absorbance
specifications for hydrocarbon solvent.
[[Page 105]]
(c) Synthetic fatty alcohols may be used as follows:
(1) As substitutes for the corresponding naturally derived fatty
alcohols permitted in food by existing regulations in this part or part
173 of this chapter provided that the use is in compliance with any
prescribed limitations.
(2) As substitutes for the corresponding naturally derived fatty
alcohols used as intermediates in the synthesis of food additives and
other substances permitted in food.
[42 FR 14491, Mar. 15, 1977, as amended at 47 FR 11837, Mar. 19, 1982;
49 FR 10105, Mar. 19, 1984; 54 FR 24897, June 12, 1989; 70 FR 72908,
Dec. 8, 2005]