[Code of Federal Regulations]
[Title 16, Volume 2]
[Revised as of January 1, 2008]
From the U.S. Government Printing Office via GPO Access
[CITE: 16CFR1500.43]
[Page 443-446]
TITLE 16--COMMERCIAL PRACTICES
CHAPTER II--CONSUMER PRODUCT SAFETY COMMISSION
PART 1500_HAZARDOUS SUBSTANCES AND ARTICLES; ADMINISTRATION AND ENFORCEMENT REGULATIONS--Table of Contents
Sec. 1500.43 Method of test for flashpoint of volatile flammable materials by Tagliabue open-cup apparatus.
Scope
1. (a) This method describes a test procedure for the determination
of open-cup flashpoints of volatile flammable materials having
flashpoints below 175 [deg]F.
(b) This method, when applied to paints and resin solutions which
tend to skin over
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or which are very viscous, gives less reproducible results than when
applied to solvents.
Outline of Method
2. The sample is placed in the cup of a Tag Open Tester, and heated
at a slow but constant rate. A small test flame is passed at a uniform
rate across the cup at specified intervals. The flashpoint is taken as
the lowest temperature at which application of the test flame causes the
vapor at the surface of the liquid to flash, that is, ignite but not
continue to burn.
Apparatus
3. The Tag open-cup tester is illustrated in Fig. 1. It consists of
the following parts, which must conform to the dimensions shown, and
have the additional characteristics as noted:
[GRAPHIC] [TIFF OMITTED] TC03OC91.051
(a) Copper bath, preferably equipped with a constant level overflow
so placed as to maintain the bath liquid level \1/8\-inch below the rim
of the glass cup.
(b) Thermometer holder. Support firmly with ringstand and clamp.
(c) Thermometer. For flashpoints above 40 [deg]F., use the ASTM Tag
Closed Tester Thermometer, range of +20 to +230 [deg]F., in 1 [deg]F.
divisions, and conforming to thermometer 9F. of ASTM Standard E 1. For
flashpoints from 20 [deg]F. to 40 [deg]F., use ASTM Tag Closed Tester,
Low Range, Thermometer 57F. For flashpoints below 20 [deg]F., use ASTM
Thermometer 33F. The original Tag Open-Cup (Paper Scale) Thermometer
will be a permissible alternate until January 1, 1962. It is calibrated
to -20 [deg]F.
(d) Glass test cup. Glass test cup (Fig. 2), of molded clear glass,
annealed, heat-resistant, and free from surface defects.
[GRAPHIC] [TIFF OMITTED] TC03OC91.052
(e) Leveling device. Leveling device or guide, for proper adjustment
of the liquid level in the cup (Fig. 3). This shall be made of No. 18-
gage polished aluminum, with a projection for adjusting the liquid level
when the sample is added to exactly \1/8\-inch below the level of the
edge or rim of the cup.
[GRAPHIC] [TIFF OMITTED] TC03OC91.053
(f) ``Micro,'' or small gas burner of suitable dimensions for
heating the bath. A screw clamp may be used to help regulate the gas. A
small electric heater may be used.
(g) Ignition taper, which is a small straight, blow-pipe type gas
burner. The test flame torch prescribed in the method of test for flash
and fire points by Cleveland Open Cup (ASTM designation: D 92) is
satisfactory.
(h) Alternative methods for maintaining the ignition taper in a
fixed horizontal plane above the liquid may be used, as follows:
(1) Guide wire, \3/32\-inch in diameter and 3\1/2\ inches in length,
with a right-angle bend \1/2\-inch from each end. This wire is placed
snugly in holes drilled in the rim of the bath, so
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that the guide wire is \5/8\-inch from the center of the cup and resting
on the rim of the cup.
(2) Swivel-type taper holder, such as is used in ASTM METHOD D 92.
The height and position of the taper are fixed by adjusting the holder
on a suitable ringstand support adjacent to the flash cup.
(i) Draft shield, consisting of two rectangular sheets of
noncombustible material, 24 inches x 28 inches, are fastened together
along the 28-inch side, preferably by hinges. A triangular sheet, 24
inches x 24 inches x 34 inches is fastened by hinges to one of the
lateral sheets (to form a top when shield is open). The interior of the
draft shield shall be painted a flat black.
Procedure
4. (a) Place the tester on a solid table free of vibration, in a
location free of perceptible draft, and in a dim light.
(b) Run water, brine, or water-glycol solution into the bath to a
predetermined level, which will fill the bath to \1/8\-inch below the
top when the cup is in place. An overflow is permissible for water-level
control.
(c) Firmly support the thermometer vertically halfway between the
center and edge of the cup on a diameter at right angles to the guide
wire, or on a diameter passing through the center of the cup and the
pivot of the taper. Place so that the bottom of the bulb is \1/4\-inch
from the inner bottom surface of the cup. If the old Tagliabue
thermometer is used, immerse to well cover the mercury bulb, but not the
wide body of the thermometer.
(d) Fill the glass cup with the sample liquid to a depth just \1/8\-
inch below the edge, as determined by the leveling device.
(e) Place the guide wire or swivel device in position, and set the
draft shield around the tester so that the sides from right angles with
each other and the tester is well toward the back of the shield.
(f) If a guide wire is used, the taper, when passed, should rest
lightly on the wire, with the end of the jet burner just clear of the
edge of the guide wire. If the swivel-type holder is used, the
horizontal and vertical positions to the jet are so adjusted that the
jet passes on the circumference of a circle, having a radius of at least
6 inches, across the center of the cup at right angles to the diameter
passing through the thermometer, and in a plane \1/8\-inch above the
upper edge of the cup. The taper should be kept in the ``off'' position,
at one end or the other of the swing, except when the flame is applied.
(g) Light the ignition flame and adjust it to form a flame of
spherical form matching in size the \5/52\-inch sphere on the apparatus.
(h) Adjust heater source under bath so that the temperature of the
sample increases at a rate of 20.5 [deg]F. per
minute. With viscous materials this rate of heating cannot always be
obtained.
Initial Test
5. Determine an approximate flashpoint by passing the taper flame
across the sample at intervals of 2 [deg]F. Each pass must be in one
direction only. The time required to pass the ignition flame across the
surface of the sample should be 1 second. Remove bubbles from the
surface of the sample liquid before starting a determination. Meticulous
attention to all details relating to the taper, size of taper flame, and
rate of passing the taper is necessary for good results. When
determining the flashpoint of viscous liquids and those liquids that
tend to form a film of polymer, etc., on the surface, the surface film
should be disturbed mechanically each time before the taper flame is
passed.
Recorded Tests
6. Repeat the procedure by cooling a fresh portion of the sample,
the glass cup, the bath solution, and the thermometer at least 20
[deg]F. below the approximate flashpoint. Resume heating, and pass the
taper flame across the sample at two intervals of 2 [deg]F. until the
flashpoint occurs.
Reporting Data
7. The average of not less than three recorded tests, other than the
initial test, shall be used in determining the flashpoint and
flammability of the substance.
Standardization
8. (a) Make determinations in triplicate on the flashpoint of
standard paraxylene and of standard isopropyl alcohol which meet the
following specifications:
(i) Specifications for p-xylene, flashpoint check grade. p-xylene
shall conform to the following requirements;
Specific gravity: 15.56 [deg]C./15.56 [deg]C., 0.860 minimum, 0.866
maximum
Boiling range: 2 [deg]C. maximum from start to dry point when tested in
accordance with the method of test for distillation of industrial
aromatic hydrocarbons (ASTM designation: D 850), or the method of test
for distillation range of lacquer solvents and diluents (ASTM)
designation D 1078). The range shall include the boilng point of pure P-
xylene, which is 138.35 [deg]C. (281.03 [deg]F.).
Purity: 95 percent minimum, calculated in accordance with the method of
test for determination of purity from freezing points of high-purity
compounds (ASTM designation: D 1016), from the experimentally determined
freezing point, measured by the method of test for measurement of
freezing points of high-purity compounds for evaluation of purity (ASTM
designation: D 1015).
(ii) Specifications for ispropanol, flash point check grade.
Isopropanol shall conform to the following requirements:
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Specific gravity: 0.8175 to 0.8185 at 20 [deg]C./20 [deg]C. as
determined by means of a calibrated pycnometer.
Distillation range: Shall entirely distill within a 1.0 [deg]C. range
which shall include the temperature 80.4 [deg]C. as determined by ASTM
method D 1078.
Average these values for each compound. If the difference between the
values for these two compounds is less than 15 [deg]F. (8.5 [deg]C.) or
more than 27 [deg]F. (16 [deg]C.), repeat the determinations or obtain
fresh standards.
(b) Calculate a correction factor as follows:
X = 92 - A
Y = 71 - B
Correction = (X + Y) / 2.
Where:
A=Observed flash of p- xylene, and
B=Observed flash of isopropyl alcohol.
Apply this correction of all determinations.
Half units in correction shall be discarded.
Precision
9. (a) For hydrocarbon solvents having flashpoints between 60
[deg]F. and 110 [deg]F., repeatability is 2
[deg]F. and the reproducibility is 5 [deg]F.
(b) If results from two tests differ by more than 10 [deg]F., they
shall be considered uncertain and should be checked. This calibration
procedure provided in this method will cancel out the effect of
barometric pressure if calibration and tests are run at the same
pressure. Data supporting the precision are given appendix III of the
1956 Report of Committee D-1 on Paint, Varnish, Lacquers and Related
Products, Proceedings, Am. Soc. Testing Mats., Vol. 56 (1956).
Note: The test apparatus and procedure described in Sec. 1500.43
may be used by manufacturers and labelers of products subject to the
Federal Hazardous Substances Act to determine flashpoint temperatures of
those products under the conditions set forth in Sec. 1500.3(c)(6)(iv),
as amended.
[51 FR 28537, Aug. 8, 1986]