Closed-cup flash point

Furfuryl alcohol is comparable to kerosene or No. 1 fuel oil in flammabiUty, the Tag Closed Cup flash point is 170°F. In the presence of concentrated mineral acids or strong organic acids, furfuryl alcohol reacts with explosive violence. Therefore, precautions should be taken to avoid contact of such materials with the alcohol. Caution is also recommended to avoid over-catalysis in the manufacture of furfuryl alcohol resins. 

The amyl alcohols are readily flammable substances / fZ-amyl alcohol is the most flammable (closed cup flash point, 19 °C). Their vapors can form explosive mixtures with air (Table 6) (5,139—147). 

Flammability—Flash Point The closed-cup flash point determination produces the most important data to determine the potential for fire. The flash point is the lowest temperature at which the vapors can be ignited under conditions defined by the test apparatus and method. 

Chemical compound Flam, limits, lower, % v/v Flam, hmits, upper, % v/v Autoignition temperature. Flash point, closed cup. Flash point, open cup. 

The equilibrium vapor pressure of a flammable hquid at its closed-cup flash point about equ s its LFL in percent by volume. Thus, the vapor pressure of toluene at its closed-cup flash point (4.4°C or 40°F) of 1.2 percent (1.2 kPa) is close to its LFL of 1.1 percent. The composite LFL of a mixture may be estimated by Le Cnatelier s Rule ... 

In view of the above adverse effects a safety factor should be applied where flammability is assessed using flash point. For pure liquids in containers the vapor should be considered potentially flammable if the liquid temperature is upward of at least 5°C below the reported flash point. For mixtures whose composition is less certain, such as petroleum mixtures, the safety factor should be about 15°C relative to the flash point [55]. Where combinations of adverse effects are identified the safety factors should be increased accordingly. A simple but very conservative approach is to assume that all liquids having a flash point <141°F may produce a flammable atmosphere under some ambient conditions, even where no mist or froth production is involved. A more practical approach is to assume that liquids handled in air at least 5-15°C below their closed cup flash points will not present ignition risks unless... 

Flammable Liquid A term used to classify certain liquids as defined by NFPA 30 as a liquid with a closed-cup flash point below 100°F (37.8°C) and Reid vapor pressures not exceeding 40 psia at 100°F (37.8°C). Flammable liquids are called Class I liquids and have three subdivisions as follows ... 

Combustible liquid A liquid having a closed-cup flash point at or above 100°F (37.8°C). 

The flash-point is a measure of the ease of ignition of the liquid. It is the lowest temperature at which the material will ignite from an open flame. The flash-point is a function of the vapour pressure and the flammability limits of the material. It is measured in standard apparatus, following standard procedures (BS 2000). Both open- and closed-cup apparatus is used. Closed-cup flash-points are lower than open cup, and the type of apparatus used should be stated clearly when reporting measurements. Flash-points are given in Sax s handbook, Lewis (2004). The flash-points of many volatile materials are below normal ambient temperature for example, ether —45°C, petrol (gasoline) —43°C (open cup). 

There are several different experimental methods used to determine flash points. Each method produces a somewhat different value. The two most commonly used methods are open cup and closed cup, depending on the physical configuration of the experimental equipment. The open-cup flash point is a few degrees higher than the closed-cup flash point. 

Standardized test using a small quantity of liquid that is slowly heated until a flash is observed when an open flame is dipped down into a covered vapor space. Flash point temperatures are normally given as open cup or closed cup, based on the type of apparatus used to measure the flash point. The open cup flash point is normally a few degrees above the closed cup flash point. 

Carbon disulfide is an extremely flammable liquid, the closed cup flash point being -22°F (-30°C). Its autoignition temperature is 90°C (194°F). Its vapors form explosive mixtures with air, within a wide range of 1.3 to 50.0% by volume in air. Reactions with certain substances can progress to explosive violence. They include finely divided metals, alkali metals, azides, fulminates, and nitrogen dioxide. 

HCN also is a highly flammable compound closed cup flash point is 0°C. The vapors form an explosive mixture with air the LEL and UEL are 6 and 41% by volume of air, respectively. 

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). 

The flash point is a measured temperature at which vapors above the surface of a liquid are just sufficiendy concentrated to propagate a flame (10). In practice, materials of concern may be in closed or open containers or may have spilled. Generally, the chosen flash point method should be related to the problem as well as to the type of material ie, open-cup methods are more significant for open containers or spills, whereas closed-cup methods give more significant information for closed containers, eg, process vessels. A number of commercial flammable liquids contain a moderate amount of noncombustible components, eg, chlorinated hydrocarbons, in order to elevate the closed-cup flash point and thus gain a more favorable classification. When the same material is analyzed by an open-cup method, the flash point is not elevated, ie, after a spill, the noncombustible material would soon be lost and the residue may be highly flammable. 

From the point of view of the potential for a fire, the closed cup flash point determination is usually the most important. In a perfect closed cup test, the vapor pressure is in equilibrium with the liquid at the temperature of the test. At the flash point, the vapor composition is at the lower flammable limit. In fact, the lower flammable limit can be estimated from vapor pressure data (for a pure compound). Open cup flash points are generally higher and, thus less conservative, than closed cup determinations. The value determined in an open cup test is subject to air movement at the open face of the cup and true vapor-liquid equilibrium probably does not occur. 

If testing is required, the essential consideration is that the test temperature must be high enough to vaporize enough fuel. For the lower flammable limit, in air at atmospheric pressure, the minimum temperature is the closed-cup flash point. As a rough guide, the upper limit requires a temperature about 40 °C higher. 

An isoparaffinic diluent, Isopar L, available from ExxonMobil Chemical Company, was chosen for the CSSX solvent. Isopar L is a blend of Ci0 to Cn branched alkanes with a distillation range of 185-211 °C, a viscosity of 1.6 centipoise at 25 °C, a specific gravity of 0.765-0.772 g/mL at 60 °F (15.6 °C), and a thermal closed-cup flash point of at least 60 °C (data courtesy of ExxonMobil Chemical Company). Aliphatic diluents are... 

PM2 5 PM10 PMA PMC PNA Pour point Particulate matter less than 2.5 ptm and 10 jam in diameter. Polymetacrylate viscosity index improver or viscosity modifier. Pensky-Martin closed cup-flash point test. Polynuclear aromatic. Measure of lubricant low-temperature flow which is 3°C above the temperature at which a normally liquid petroleum product maintains fluidity. Oil forms a honeycomb or crystals at low... 

The U. S. Department of Transportation has announced (9) that future labeling regulations for flammable liquids may be based on their TCC flash points. If this change is made, the empirical calculation technique proposed here is expected to be equally applicable to predicting TCC data if the closed cup flash points of the individual solvents are substituted in basic calculation data. No attempts have yet been made to predict closed cup data, but one might expect that the vapor space in the closed cup would be more easily simulated than that in the open cup tester. 

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