Flash point values

Hughes, J.M., Hardy, D.R., and Beal, EJ. A flash point value for n-dodecane based on the manual Pensky-Martens closed cup method (ASTM-D-93), Energy Fuels, 10(6) 1276-1277, 1996. 

According to Occupational Safety and Health Administration (OSHA), compounds with flash point values <100°F (37.8°C) are considered flammable. Department of Transportation (DOT) and United Nations (UN) codes rate compounds flammable when the flash point is <141°F (60.5°C). 

Cleveland Open Cup (COC) and Pensky-Martens (PM). The closed cup flash point value is usually several degrees lower (more flammable) than the open cup, as the test in the former case is made on a saturated vapor-air mixture, whereas in the latter case the vapor has free access to air and thus is slightly less concentrated. For this reason, open cup values more nearly simulate actual conditions (see below). 

Cleveland Open Cup (COC) and Pensky-Martens (PM). The dosed cup flash point value is usually several degrees lower (more flammable) than the open cup, as the test in the former case is made on a saturated vapor-air mixture, whereas in the latter case the vapor has free access to air and thus is slightly less concentrated, For tliis reason, open cup values more nearly simulate actual conditions (see below), Fire Point (fire pt). Tliis is the lowest temperature at which a mixture of air and vapor continue to burn in an open container when ignited. It is usually above the flash point. Where the flash point is available, only it is given if it is not, the fire point may be given. It is at least as significant as the flash point as an indication of the fire hazard of... 

Flashpoint is the lowest temperature at which a chemical gives off enough vapor to form an igni-table mixture with air near the surface of the liquid when exposed to an ignition source. Flash point values are used to rate the flammability or combustibility of a substance. 

The great variety of methods described explains why no example is presented here of the basic measuring set-up. It is recommended to consult the primary sources for tins purpose, which are referenced in Table 3-7. It is rather more important is to discuss parameters which influence the absolute flash-point values and to make some remarks regarding their interpretation. It is important to understand that the flash-point is no physicochemical property of a substance but a technical safety data, the value of which strongly depends on the measuring technique. 

Table 4.1 Closed cup and open cup flash point values for typical solvents...

Flash point values quoted in the literature, in general, are for pure solvents. The presence of contaminants can have a significant effect on the flash point, particularly if the contaminant is relatively more volatile. For example, pure ethylene glycol has a flash point of 111°C. However, the flash point is reduced to 29°C when acetaldehyde at a level of only 2% is present. Similarly, when handling solvent mixtures, a small change in the composition can have a significant effect on the flash point. Thus, whenever possible, flash points should be measured when it is known or suspected that more than one component will be present. 

Flash Point (fl p) The flash point is defined as the minimum temperature at which a substance releases ignitable flammable vapors in the presence of an ignition source, e.g., spark or flame. Flash points may be determined by two methods—Tag closed cup (ASTM method D56) or Cleveland open cup (ASTM method D93). Uifless noted otherwise, all flash point values represent closed cnp method determinations. Flash point values determined by the open cnp method are slightly higher than those determined by the closed cnp method however, the open eup method is more representative of actual conditions. 

For example, using the database prepared by the Chemistry Department at the University of Akron http //ull.chemistry.uakron. edu/erd/) which is considered to an academic work, the flash point of perchloroethylene is reported as 113°F. In addition the Royal Society of Chemistry s data portal Chemspider (http /AA/ww. chemspider.com/Chemical-Structure.29106.html) reports a value of 83.4°F. However, various internet sources, such as Wikipedia http //en.wikipedia.org/wiki/Fetrachloroethylene), the Center for Disease Control s Pocket Guide to Chemical Hazards (http //www. cdc.gov/niosh/npg/npgd0599.html), and most MSDSs report that the flash point value is "NA" which is presumed to mean "none."... 

Note A2.3—Materials, purities, flash point values and limits stated in Table A2.1 were develop in an ASTM interiaboratoiy program (see RR SI5-1010) to determine suitability of use for verification fluids in flash p( test methods. Other matmials, purities, flash point values, and Ufflits can be suitable when produced acooiding to the practices of ASTM RR D02-I0()7 or ISO Girides 34 and 35. Certificates of performance of such materials should be consulted before use, as the flash point value wUl vary dependent on the condition of each CRM batch. 

There are no universally accepted wet analytical methods for the characteri2ation of quaternary ammonium compounds. The American Oil Chemists Society (AOCS) has estabhshed, however, a number of appHcable tests (180). These include sampling, color, moisture, amine value, ash, iodine value, average molecular weight, pH, and flash point. 

Trinidad asphalt has a relatively uniform composition of 29% water and gas, 39% bitumen soluble in carbon disulfide, 27% mineral matter on ignition, and 5% bitumen that remains adsorbed on the mineral matter. Refining is essentially a process of dehydration by heating the cmde asphalt to ca 165°C. The refined product averages 36% mineral ash with a penetration at 25°C of about 2 (0.2 mm), a softening point (ring and ball method) of 99°C, a flash point (Cleveland open cup) of 254°C, a sulfur content of 3.3%, and a saponification value of 45 mg KOH/g. The mineral matter typically contains... 

Flash Point. As fuel oil is heated, vapors are produced which at a certain temperature "flash" when ignited by an external ignition source. The flash point is the lowest temperature at which vapor, given off from a Hquid, is in sufficient quantity to enable ignition to take place. The flash point is in effect a measure of the volatiHty of the fuel. The measurement of flash point for pure Hquids is relatively straightforward. However, the measured value may depend slightly on the method used, especially for Hquid mixtures, since the composition of the vapor evolved can vary with the heating rate. Special... 

Flash points, lower and upper flammability limits, and autoignition temperatures are the three properties used to indicate safe operating limits of temperature when processing organic materials. Prediction methods are somewhat erratic, but, together with comparisons with reliable experimental values for families or similar compounds, they are valuable in setting a conservative value for each of the properties. The DIPPR compilation includes evaluated values for over 1000 common organics. Detailed examples of most of the methods discussed are available in Danner and Daubert."... 

Small concentrations of volatile components in a liquid mixture may accumulate in the vapor space of a container over time and appreciably reduce the flash point relative to the reported closed-cup value. This may be the result of degassing, chemical reaction or other mechanism. An example is bitumen [162]. Similarly, if a tank truck is not cleaned between deliveries of gasoline and a high flash point liquid such as kerosene or diesel oil, the mixture might generate a flammable atmosphere both in the tmck tank and the receiving tank. Contamination at the thousand ppm level may create hazards (5-1.4.3 and 5-2.5.4). Solids containing upward of about 0.2 wt% flammable solvent need to be evaluated for flammable vapor formation in containers (6-1.3.2). 

The vapor pressure (VP) can be used in conjunction with a measured LEE to estimate flash point. When this is done it is usually found that the calculated flash point is less than the measured value owing to limitations in the flash point test technique (5-1.1.1). Conversely, the LEE can be estimated only approximately from the flash point. The VP can also be used to replace the 10... 

FIRE POINT The minimum temperature at which a mixture of gas/vapour and air continues to burn in an open container when ignited. The value is generally above the flash point. 

Flash point determinations may be made in elosed or open eontainers, giving different values ... 

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