Scope
(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 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 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
(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
(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 maximumBoiling 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 boiling 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: 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 - AY = 71 - B Correction = (X + Y) / 2. Where: A=Observed flash of p- xylene, andB=Observed flash of isopropyl alcohol. Apply this correction of all determinations.Half units in correction shall be discarded.
Precision
(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] Sec. 1500.43a Method of test for flashpoint of volatile flammablematerials.
(a) Scope. (1) This method describes the test procedure which the Commission will use for the determination of the flashpoint of volatile flammable materials, using a Setaflash \1\ low-range closed tester, or an apparatus producing equivalent results. The method described in this section is essentially a Setaflash equilibrium procedure which closely parallels the test method designated ASTM D 3828-81, ``Standard Test Methods for Flash Point by Setaflash Closed Tester,'' published by the American Society for Testing and Materials (ASTM), 1916 Race Street, Philadelphia, Pennsylvania 19103. Manufacturers and labelers of products subject to labeling and other requirements under the Federal Hazardous Substances Act may use other apparatus and/or test methods which produce equivalent results.---------------------------------------------------------------------------
\1\ Setaflash is a registered trademark of Stanhope-Seta Limited, Surrey, England.---------------------------------------------------------------------------
(2) At the option of the user, the procedures described in this section may be used to determine the actual flashpoint temperature of a sample or to determine whether a product will or will not flash at a specified temperature (flash/no flash).
(3) If the substance to be tested has a viscosity greater than 150 Stokes at 77 [deg]F (25 [deg]C), see paragraph (n) of this section for modifications to the testing procedure.
(4) If the Commission has reason to believe on the basis of reliable experience or other relevant information or data that the flammability hazard of a substance is greater or less than its flammability classification based on flashpoint temperature determined in accordance with this Sec. 1500.43a and that the substance should be reclassified, the Commission will initiate a rulemaking proceeding for reclassification of the substance. Product manufacturers and labelers may use reliable experience or other relevant information or data in addition to the flashpoint temperature of a substance as a basis for compliance with any applicable requirements of the Federal Hazardous Substances Act in the absence of a rule issued by the Commission to reclassify the substance.
(b) Summary of test methods. (1) Method A--Flash/No Flash Test. A specified volume of sample is introduced by a syringe into the cup of the apparatus that is set and maintained at the specified temperature. After a specific time a test flame is applied and an observation made as to whether or not a flash occurred. Test procedures are set forth in detail in Sec. 1500.43a(i).
(1) Method A--Flash/No Flash Test. A specified volume of sample is introduced by a syringe into the cup of the apparatus that is set and maintained at the specified temperature. After a specific time a test flame is applied and an observation made as to whether or not a flash occurred. Test procedures are set forth in detail in Sec. 1500.43a(i).
(2) Method B--Finite (or Actual) Flashpoint. (i) A specified voume of sample is introduced into the cup of the apparatus that is maintained at the expected flashpoint. After a specified time a test flame is applied and the observation made whether or not a flash occurred.
(i) A specified voume of sample is introduced into the cup of the apparatus that is maintained at the expected flashpoint. After a specified time a test flame is applied and the observation made whether or not a flash occurred.
(ii) The specimen is removed from the cup, the cup cleaned, and the cup temperature adjusted 5 [deg]C (9 [deg]F), lower or higher depending on whether or not a flash occurred previously. A fresh specimen is introduced and tested. This procedure is repeated until the flashpoint is established within 5 [deg]C (9 [deg]F).
(iii) The procedure is then repeated at 1 [deg]C (2 [deg]F) intervals until the flashpoint is determined to the nearest 1 [deg]C (2 [deg]F).
(iv) If improved accuracy is desired the procedure is repeated at 0.5 [deg]C (1 [deg]F). Test procedures are set forth in detail at Sec. 1500.43a(j).
(3) The test procedures will be modified, where necessary, to ensure that the results obtained reflect the hazard of the substance under reasonably foreseeable conditions of use. Thus, for example, the material, if a mixture, will normally be tested as it comes from the container, and/or after a period of evaporation. The period of evaporation for a material which is a mixture will normally be the time required for the mixture to evaporate in an open beaker under ambient conditions to 90 percent of its original volume, or a period of four hours, whichever occurs first. However, this period of evaporation will be changed if the results obtained do not represent the hazard of the substance under reasonably foreseeable conditions of use.
(c) Definition of flashpoint. The lowest temperature of the sample, corrected to a barometric pressure of 101.3 kPa (760 mm Hg), at which application of a test flame causes the vapor of the sample to ignite under specified conditions of test. The sample is deemed to have flashed when a large flame appears and instantaneously propagates itself over the surface of the sample. Occasionally, particularly near actual flashpoint, the application of the test flame will cause a halo or an enlarged flame; this is not a flash and should be ignored.
(d) Test apparatus. The test apparatus is an equilibrium closed-cup tester with a range up to 100 [deg]C (212 [deg]F). The essential dimensions and requirements are shown in figure 1 and table 3, and are described in Sec. 1500.43a(m). Closed-cup flashpoint testers and accessories meeting these requirements are available from commercial suppliers and distributors of laboratory equipment.
(e) Safety precautions. The operator must exercise and take appropriate safety precautions during the initial application of the test flame to the sample. Samples containing low-flash material may give an abnormally strong flash when the test flame is first applied.
(f) Preparation of samples. (1) Erroneously high flashpoints may be obtained if precautions are not taken to avoid the loss of volatile material. In preliminary tests of materials taken directly from the container, do not open containers unnecessarily and make a transfer unless the sample temperature is at least 10 [deg]C (18 [deg]F) below the expected flashpoint. Do not use samples in leaky containers for this test.
(1) Erroneously high flashpoints may be obtained if precautions are not taken to avoid the loss of volatile material. In preliminary tests of materials taken directly from the container, do not open containers unnecessarily and make a transfer unless the sample temperature is at least 10 [deg]C (18 [deg]F) below the expected flashpoint. Do not use samples in leaky containers for this test.
(2) Do not store samples in plastic (polyethylene, polypropylene, etc.) bottles since volatile material may diffuse through the walls of the bottle.
(3) A 2-ml specimen is required for each test. If possible, obtain at least a 50-ml sample from the bulk test site and store in a clean, tightly closed container.
(g) Preparation of apparatus. (1) Place the tester on a level, stable surface. Unless tests are made in a draft-free area, surround the tester on three sides with a shield for protection. Do not rely on tests made in a laboratory draft hood or near ventilators.
(1) Place the tester on a level, stable surface. Unless tests are made in a draft-free area, surround the tester on three sides with a shield for protection. Do not rely on tests made in a laboratory draft hood or near ventilators.
(2) Read the manufacturer's instructions on the care and servicing of the instrument and for correct operation of its controls.
(h) Calibration and standardization. (1) Before initial use determine and plot the relationship between the temperature control dial and the thermometer readings at each major (numbered) dial division as follows:
Turn the temperature control knob \2\ fully counterclockwise (``O'' reading). Advance the temperature control knob clockwise until the indicator light is illuminated. \3\ Advance the knob clockwise to the next numbered line. After the thermometer mercury column ceases to advance, record the dial reading and the temperature. Advance the knob clockwise to the next numbered line. After the thermometer mercury column ceases to advance, read the dial reading and the temperature. Repeat this procedure through the full range of the instrument. Plot the dial readings versus the respective temperatures.---------------------------------------------------------------------------
\2\ If the instrument has two temperature control knobs, set the fine control (center, small knob) at its mid-position and allow it to remain there throughout the calibration. The calibration is determined by adjusting the coarse control (large, outer knob) only.
\3\ When using the tester, it will be found that the indicator light may not illuminate and the temperature may not rise until a temperature control dial setting between one and two is reached.---------------------------------------------------------------------------
(2) Standardize the instrument using a sample of material meeting the specifications in table 1. If the average of two determinations falls within the acceptable limits the instrument is assumed to be operating properly. If the average of the two determinations does not fall within this range, check the manufacturer's operating and maintenance instructions and determine that they are being followed. In particular, be sure that the cup lid assembly makes a vapor-tight seal with the cup, the shutter provides a light-tight seal, and that adequate heat transfer paste surrounds the thermometer bulb and the immersed portion of the barrel.
(i) Test Method A--for determining Flash/No Flash. (1) Determine the target flashpoint as follows:
(1) Determine the target flashpoint as follows:
(i) Target flashpoint, [deg]C=Sc--0.25 (101.3--A)
(ii) Target flashpoint, [deg]C=Sc--0.03 (760-B)
(iii) Target flashpoint, [deg]F=Sf--0.06 (760-B) where: Sc=specification, or uncorrected target, flashpoint, [deg]C,Sf=specification, or uncorrected target, flashpoint, [deg]F,B=ambient barometric pressure, mm Hg, \4\ and---------------------------------------------------------------------------
\4\ The barometric pressure used in this calculation must be the ambient pressure for the laboratory at the time of test. Many aneroid barometers, such as those used at weather stations and airports, are precorrected to give sea-level readings; these must not be used. --------------------------------------------------------------------------- ---------------------------------------------------------------------------A=ambient barometer pressure, kPa. \4\
(2) Inspect the inside of the sample cup, lid, and shutter mechanism for cleaniness and freedom from contamination. Use an absorbent paper tissue to wipe clean, if necessary. Put cover in place and lock securely. The filing orifice may be convenienty cleaned with a pipe cleaner.
(3) Set the instrument at the target temperature.
(i) For target temperature below ambient. The instrument power switch is to be in the off position. Fill the refigerant-charged cooling block with a suitable material. \5\ Raise the lid and shutter assembly, and position the base of the block in the sample cup, being careful not to injure or mar the cup. When the thermometer reads approximately 6 to 10 [deg]C (10 to 20 [deg]F) below the target temperature, remove the cooling block and quickly dry the cup with a paper tissue to remove any moisture. Immediately close the lid and shutter assembly and secure. Prepare to introduce the sample using the syringe, both of which have been precooled to a temperature 5 to 10 [deg]C (10 to 20 [deg]F) below the target temperature.---------------------------------------------------------------------------
\5\ If the target or specification temperature is not less than 5 [deg]C (40 [deg]F) crushed ice and water may be used as charging (cooling) fluid. If below 5 [deg]C (40 [deg]F), a suitable charging (cooling) fluid is solid carbon dioxide (dry ice) and acetone. If the refrigerant charged cooling module is unavailable, refer to the manufacturer's instruction manual for alternative methods of cooling.---------------------------------------------------------------------------
(A) Caution: Do not cool the sample block below -38 [deg]C, the freezing point of mercury.
(B) Caution: Acetone is extremely flammable. Keep away from heat, sparks, and flames and keep container closed when not actually pouring acetone. Use only in a well-ventilated area. Avoid inhalation and contact with the eyes or skin. Use cloth or leather gloves, goggles or safety shield, and keep dry ice in a canvas bag, especially when cracking.
(ii) For target temperature above ambient. Switch the instrument on and turn the coarse temperature control knob fully clockwise (full on) causing the indicator light to illuminate. \6\ When the thermometer indicates a temperature about 3 [deg]C (5 [deg]F) below the target (or specification) temperature, reduce the heat input to the sample cup by turning the coarse temperature control knob counter-clockwise to the desired control point (see Sec. 1500.43a(i)(1)). When the indicator light slowly cycles on and off read the temperature on the thermometer. If necessary, adjust the fine (center) temperature control knob to obtain the desired test (target) temperature. When the test temperature is reached and the indicator lamp slowly cycles on and off, prepare to introduce the sample.---------------------------------------------------------------------------
\6\ The target temperature may be attained by originally turning the coarse temperature control knob to the proper setting (see Sec. 1500.43a(h)(1) for the temperature desired rather than the maximum setting (full on). The elapsed time to reach the temperature will be greater, except for maximum temperature. However, less attention will be required during the intervening period.---------------------------------------------------------------------------
(4) Charge the syringe with a 2-ml specimen of the sample \7\ to be tested; transfer the syringe to the filling orifice, taking care not to lose any sample; discharge the test specimen into the cup by fully depressing the syringe plunger, remove the syringe.---------------------------------------------------------------------------
\7\ For target or expected temperatures below ambient, both syringe and sample must be precooled to cup temperature (see Sec. 1500.43a(i)(3)(i)) before the specimen is taken.---------------------------------------------------------------------------
(5)(i) Set the timer \8\ by rotating its knob clockwise to its stop. Open the gas control valve and light the pilot and test flames. Adjust the test flame with the pinch valve to conform to the size of the 4-mm (5/32-in.) gage.---------------------------------------------------------------------------
(i) Set the timer \8\ by rotating its knob clockwise to its stop. Open the gas control valve and light the pilot and test flames. Adjust the test flame with the pinch valve to conform to the size of the 4-mm (5/32-in.) gage.---------------------------------------------------------------------------
\8\ For target temperatures below ambient, do not set the timer. Adjust the test flame and allow the temperature to rise under ambient conditions until the target temperature is reached. Immediately apply the test flame as detailed.---------------------------------------------------------------------------
(ii) After the time signal indicates the specimen is at test temperature \8\, apply the test flame by slowly and uniformly opening the shutter and closing it completely over a period of approximately 2\1/2\ s. \9\ Watch closely for a flash at the cup openings.---------------------------------------------------------------------------
\9\ Never apply the test flame to the specimen more than once. Fresh portions of the sample must be used for each test.---------------------------------------------------------------------------
(iii) The sample is deemed to have flashed when a large flame appears and instantaneously propagates itself over the surface of the sample (see Sec. 1500.43a(c)).
(6) Record the test results as ``flash'' or ``no flash'' and the test temperature.
(7) Turn off the pilot and test flames using the gas control valve. Remove the sample and clean the instrument. It may be necessary to allow the cup temperature to decline to a safe level before cleaning.
(j) Test Method B--for determining Finite or Actual Flashpoint. (1) Inspect the inside of the sample cup, lid, and shutter mechanism for cleanliness and freedom from contamination. Use an absorbent paper tissue to wipe clean, if necessary. Put cover in place and lock securely. The filling orifice may be conveniently cleaned with a pipe cleaner.
(1) Inspect the inside of the sample cup, lid, and shutter mechanism for cleanliness and freedom from contamination. Use an absorbent paper tissue to wipe clean, if necessary. Put cover in place and lock securely. The filling orifice may be conveniently cleaned with a pipe cleaner.
(2) For expected flashpoints below ambient. (i) The instrument power switch is to be in off position. Fill the refrigerant-charged cooling block with a suitable material. \5\ Raise the lid and shutter assembly, and position the base of the block in the sample cup, being careful not to injure or mar the cup. When the thermometer reaches a temperature 5 to 10 [deg]C (10 to 20 [deg]F) below the expected flashpoint, remove the cooling block and quickly dry the cup with a paper tissue to remove any moisture. Immediately close the lid and shutter assembly and secure. Prepare to introduce the sample using the syringe, both of which have been precooled to a temperature 5 to 10 [deg]C (10 to 20 [deg]F) below the expected temperature (See Sec. 1500.43a(j)(5)).
(i) The instrument power switch is to be in off position. Fill the refrigerant-charged cooling block with a suitable material. \5\ Raise the lid and shutter assembly, and position the base of the block in the sample cup, being careful not to injure or mar the cup. When the thermometer reaches a temperature 5 to 10 [deg]C (10 to 20 [deg]F) below the expected flashpoint, remove the cooling block and quickly dry the cup with a paper tissue to remove any moisture. Immediately close the lid and shutter assembly and secure. Prepare to introduce the sample using the syringe, both of which have been precooled to a temperature 5 to 10 [deg]C (10 to 20 [deg]F) below the expected temperature (See Sec. 1500.43a(j)(5)).
(ii) Caution: Do not cool the sample block below -38 [deg]C, the freezing point of mercury.
(3) For tests where the expected flashpoint is above ambient. Turn the coarse temperature control knob fully clockwise (full on) causing the indicator light to illuminate. When the thermometer reaches a temperature 3 [deg]C (5 [deg]F) below the estimated flashpoint, turn the coarse temperature knob counter-clockwise to the dial reading representing the estimated flashpoint temperature as shown on the calibration curve (See Sec. 1500.43a(h)(1)). When the indicator light slowly cycles on and off, read the temperature on the thermometer. If necessary, adjust the fine temperature control knob to obtain the exact desired temperature.
(4)(i) Charge the syringe \7\ with a 2 ml specimen of the sample \7\ to be tested; transfer the syringe to the filling orifice, taking care not to lose any sample; discharge the test specimen into the cup by fully depressing the syringe plunger; remove the syringe.
(i) Charge the syringe \7\ with a 2 ml specimen of the sample \7\ to be tested; transfer the syringe to the filling orifice, taking care not to lose any sample; discharge the test specimen into the cup by fully depressing the syringe plunger; remove the syringe.
(ii) Set the timer \10\ by rotating its knob clockwise to its stop. Open the gas control valve and ignite the pilot and test flames. Adjust the test flame with the pinch valve to conform to the size of the 4-mm (\5/32\-in.) gage.
(iii) After the audible time signal indicates the specimen is at test temperature, \10\ apply the test flame by slowly and uniformly opening the shutter and then closing it completely over a period of approximately 2\1/2\ s. Watch closely for a flash at the cup opening.---------------------------------------------------------------------------
\10\ For expected flashpoint below ambient, do not set the timing device. Adjust the test flame. Allow the temperature to rise under ambient conditions until the temperature reaches 5 [deg]C (9 [deg]F) below the expected flashpoint. Immediately apply the test flame.---------------------------------------------------------------------------
(iv) The sample is deemed to have flashed only if a large flame appears and instantaneously propagates itself over the surface of the sample. (See Sec. 1500.43a(c).)
(v) Turn off the pilot and test flames using the gas control valve. When the cup temperature declines to a safe level, remove the sample and clean the instrument.
(5)(i) If a flash was observed in Sec. 1500.43a(j)(4)(iii) repeat the procedure given in Sec. 1500.43a(j)(2) or (3), and in Sec. 1500.43a(j)(4), testing a new specimen at a temperature 5 [deg]C (9 [deg]F) below that at which the flash was observed.
(i) If a flash was observed in Sec. 1500.43a(j)(4)(iii) repeat the procedure given in Sec. 1500.43a(j)(2) or (3), and in Sec. 1500.43a(j)(4), testing a new specimen at a temperature 5 [deg]C (9 [deg]F) below that at which the flash was observed.
(ii) If necessary, repeat the procedure in Sec. 1500.43a(j)(5)(i), lowering the temperature 5 [deg]C (9 [deg]F) each time, until no flash is observed. \9\
(iii) Proceed to Sec. 1500.43a(j)(7).
(6)(i) If no flash was observed in Sec. 1500.43a(j)(4)(iii) repeat the procedure given in Sec. 1500.43a(j)(2) or (3), and in Sec. 1500.43a(j)(4), testing a fresh specimen at a temperature 5 [deg]C (9 [deg]F) above that at which the specimen was tested in Sec. 1500.43a(j)(4)(iii).
(i) If no flash was observed in Sec. 1500.43a(j)(4)(iii) repeat the procedure given in Sec. 1500.43a(j)(2) or (3), and in Sec. 1500.43a(j)(4), testing a fresh specimen at a temperature 5 [deg]C (9 [deg]F) above that at which the specimen was tested in Sec. 1500.43a(j)(4)(iii).
(ii) If necessary repeat the procedure in Sec. 1500.43a(j)(6)(i), above, raising the temperature 5 [deg]C (9 [deg]F) each time until a flash is observed. \9\
(7) Having established a flash within two temperatures 5 [deg]C (9 [deg]F) apart, repeat the procedure at 1 [deg]C (2 [deg]F) intervals from the lower of the two temperatures until a flash is observed. \9\ Record the temperature of the test when this flash occurs as the flashpoint, allowing for any known thermometer correction. Record the barometric pressure. \4\
(8) The flashpoint determined in Sec. 1500.43a(j)(7) will be to the nearest 1 [deg]C (2 [deg]F). If improved accuracy is desired (that is, to the nearest 0.5 [deg]C (1 [deg]F)), test a fresh specimen at a temperature 0.5 [deg]C (1 [deg]F) below that at which the flash was observed in Sec. 1500.43a(j)(7). If no flash is observed, the temperature recorded in Sec. 1500.43a(j)(7), is the flashpoint to the nearest 0.5 [deg]C (1 [deg]F). If a flash is observed at the lower temperature, record this latter temperature as the flashpoint.
(9) Turn off the pilot and test flames using the gas control valve. When the cup temperature declines to a safe level, remove the sample and clean the instrument.
(k) Calculations. If it is desired to correct the observed finite flashpoint for the effect of barometric pressure, proceed as follows: Observe and record the ambient barometric pressure \4\ at the time of the test. If the pressure differs from 101.3 kPa (760 mm Hg), correct the flashpoint as follows:
(1) Corrected flashpoint ([deg]C)=C+0.25 (101.3-A)
(2) Corrected flashpoint ([deg]F)=F+0.06 (760-B)
(3) Corrected flashpoint ([deg]C)=C+0.03 (760-B) Where: F=Observed flashpoint, [deg]F,C=observed flashpoint, [deg]C,B=ambient barometric pressure, mm Hg; andA=ambient barometric pressure, kPa.
(l) Precision. The precision of the method as determined by statistical examination of interlaboratory results is as follows:
(1) Repeatability. The difference between two test results obtained by the same operator with the same apparatus under constant operating conditions on identical test material, would, in the long run, in the normal and correct operation of the test method, exceed the values shown in table 2 only in 1 case in 20.
(2) Reproducibility. The difference between two single and independent results obtained by different operators working in different laboratories on identical test material, would, in the long run, in the normal and correct operation of the test method, exceed the values shown in table 2 only in 1 case in 20.
(m) Flash Test Apparatus. (1)(i) Unit consisting of an aluminum alloy or nonrusting metal block of suitable conductivity with a cylindrical depression, or sample cup, over which is fitted a cover. A thermometer is embedded in the block.
(1)(i) Unit consisting of an aluminum alloy or nonrusting metal block of suitable conductivity with a cylindrical depression, or sample cup, over which is fitted a cover. A thermometer is embedded in the block.
(i) Unit consisting of an aluminum alloy or nonrusting metal block of suitable conductivity with a cylindrical depression, or sample cup, over which is fitted a cover. A thermometer is embedded in the block.
(ii) The cover is fitted with an opening slide and a device capable of inserting an ignition flame (diameter 40.5 mm) into the well when the slide device shall intersect the plane of the underside of the cover. The cover is also provided with an orifice extending into the sample well for insertion of the test sample and also a suitable clamping device for securing the cover tightly to the metal block. The three openings in the cover shall be within the diameter of the sample well. When the slide is in the open position, the two openings in the slide shall coincide exactly with the two corresponding openings in the cover.
(iii) Electrical heaters are attached to the bottom of the cup in a manner that provides efficient transfer of heat. An electronic heat control is required to hold the equilibrium temperature, in a draft-free area, within 0.1 [deg]C (0.2 [deg]F) for the low-temperature tester. A visual indicator lamp shows when energy is or is not being applied. Energy may be supplied from 120 or 240 V, 50 or 60 Hz main service.
(2)(i) Test flame and pilot flame-regulatable test flame, for dipping into the sample cup to try for flash, and a pilot flame, to maintain the test flame, are required. These flames may be fueled by piped gas service. A gage ring 4mm (5/32 in.) in diameter, engraved on the lid near the test flame, is required to ensure uniformity in the size of the test flame.
(i) Test flame and pilot flame-regulatable test flame, for dipping into the sample cup to try for flash, and a pilot flame, to maintain the test flame, are required. These flames may be fueled by piped gas service. A gage ring 4mm (5/32 in.) in diameter, engraved on the lid near the test flame, is required to ensure uniformity in the size of the test flame.
(ii) Caution: Never recharge the self-contained gas tank at elevated temperature, or with the pilot or test flames lighted, nor in the vicinity of other flames.
(iii) Audible Signal is required. The audiable signal is given after 1 min in the case of the low-temperature tester.
(iv) Syringe. 2ml capacity, equipped with a needle suitable for use with the apparatus, adjusted to deliver 2.000.05 ml.
(3) Essential dimensions of the test apparatus are set forth in table 3.
(n) Testing high-viscosity liquids. (1) High-viscosity materials may be added to the cup by the following procedure:
(1) High-viscosity materials may be added to the cup by the following procedure:
(i) Back load a 5 or 10-ml syringe with the sample to be tested and extrude 2 ml into the cup. Spread the specimen as evenly as possible over the bottom of the cup.
(ii) If the sample cannot be loaded into a syringe and extruded, other means of adding the sample to the cup may be used such as a spoon. Add approximately 2 ml of material to the spoon and then push the material from the spoon into the cup.
(iii) If the test specimen does not close the sampling port in the cup, seal the cup externally by suitable means.
(2) Using the appropriate procedure, either Method A in Sec. 1500.43a(i) or Method B in Sec. 1500.43a(j), determine the flashpoint of the specimen which has been added to the tester in accordance with Sec. 1500.43a(n)(i), except that the time specified is increased from 1 to 5 minutes for samples at or above ambient temperature.
Table 1--Calibration of TesterMaterial.................................. p-xylene\A\ (Caution).\B\Specific gravity. 15.6/15.6 [deg]C (60/60 0.850 to 0.866.
[deg]F).Boiling range............................. 2 [deg]C maximum including
138.35 [deg]C (281.03
[deg]F).Freezing point............................ 11.23 [deg]C (52.2 [deg]F)
minimum.Flashpoint [deg]C (acceptable range)...... 25.6 0.5 (78 1 [Phi]).
\A\ Available as Flash Point Check Fluid (p-xylene) from Special
Products Div., Phillips Petroleum Co., Drawer `O,' Borger, Texas
79007.\B\ Caution: Handle xylene with care. Avoid inhalation; use only in a
well-ventilated area. Avoid prolonged or repeated contact with skin.
Keep away from flames and heat, except as necessary for the actual
flash point determination.
Table 2--Repeatability and Reproducibility------------------------------------------------------------------------
Repeatability,
Temperature, [deg]C ([deg]F) [deg]C Reproducibility,
([deg]F) [deg]C ([deg]F)------------------------------------------------------------------------20(68)................................ 0.5(0.9) 1.4(2.6)70(158)............................... 0.5(0.9) 2.9(5.3)93(200)............................... 1.3(2.3) 4.9(8.8)150(300).............................. 2.0(3.6) 7.5(13.5)200(400).............................. 2.6(4.7) 9.9(17.9)260(500).............................. 3.3(5.9) 12.4(22.3)------------------------------------------------------------------------
Table 3--Essential Dimensions of Flash Test Apparatus \A B\
Sample BlockBlock diameter............................................ 61.5-62.5Sample well diameter...................................... 49.40-49.70Sample well depth......................................... 9.70-10.00Top of block to center of thermometer hole................ 16.00-17.00Diameter of thermometer hole (approx.).................... 7.0004
CoverLarge opening length...................................... 12.42-12.47Large opening width....................................... 10.13-10.18Small opening length...................................... 5.05-5.10Small opening width....................................... 7.60-7.65Distance between extreme edges of small openings.......... 48.37-48.32Filling orifice diameter.................................. 4.00-4.50Bore or filler tube....................................... 1.80-1.85Maximum distance of filler tube from base of well with 0.75
cover closed (max.)......................................
SlideLarge opening length...................................... 12.42-12.47Large opening width....................................... 10.13-10.18Small opening length...................................... 5.05-5.10Small opening width....................................... 7.60-7.65Near edge of large opening to end of slide................ 12.80-12.85Extremes of large and small openings...................... 30.40-30.45
JetLength of jet............................................. 18.30-18.40External diameter at end of jet........................... 2.20-2.60Bore of jet............................................... 1.60-1.65Height of jet center above top surface of cover........... 11.00-11.20Jet pivot to center of block with cover closed............ 12.68-12.72
\A\ The O-seal or gasket which provides a seal when the cover is shut,
should be made of a heat-resistant material capable of withstanding
temperatures up to 150 [deg]C for the low-range apparatus.\B\ When in position, the thermometer bulb should be surrounded with
heat-conducting thermoplastic compound, such as a paste comprised of
zinc oxide and mineral oil. [GRAPHIC] [TIFF OMITTED] TC03OC91.054 [51 FR 28539, Aug. 8, 1986]