Toluene, flash-point

Higher dimeric ketenes are flammable but have higher flash points and are less reactive than diketene. Almost no data are available. Diketene can be disposed of by incineration, preferably after dilution with an inert solvent such as toluene. Higher ketene dimers can also be incinerated. 

The PMBs, as higher homologues of toluene and xylenes, ate handled in a similar manner, even though their flash points are higher (see Table 1). Containers are tightly closed and use areas should be ventilated. Breathing vapors and contact with the skin should be avoided. Toxicity and primary... 

Tables 16 and 17 Hst tke analytical test methods for different properties of interest. The Manufacturing Chemists Association, Inc. (MCA) has pubUshed the Chemical Safety Data Sheet SD 63, which describes in detail procedures for safe handling of use of toluene (46). The Interstate Commerce Commission classifies toluene as a flammable Hquid. Accordingly, it must be packaged in authorized containers, and shipping must comply with ICC regulations. Properties related to safe handling are autoignition temperature, 536°C explosive limits, 1.27—7.0 vol % in air and flash point 4.4°C, closed 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 ... 

Pressure affects flash point. A decrease in pressure lowers the flash point. With toluene, for example, at two-thirds of an atmosphere the vapor pressure must be only 0.74 kPa (5.6 mm Hg) to equal the LFL of 1.1 percent. (No significant difference in LFL will exist at two-thirds of an atmosphere compared to the published LFL of 1.1 percent at one atmosphere.) This vapor pressure occurs at —3°C, corresponding to a decrease in flash point of about 7.4°C from one atmosphere. Conversely, an increase in pressure raises the flash point. 

Analysis. 1-MNN is best identified by redn to the amine with Sn and 10% HC1, which is converted to the benzenesulfonamide, mp 167° or the benzamide, mp 160° (Ref 36). The picrate, CA Registry No 29754-26-5, is also known (Ref 37). It has been found in cn de TNT recovered from Comp B (probably anCng from the presence of naphthalene in coml toluene), from which it was isolated by gas chromatography and identified by mass spec (Ref 40). Standard anal procedures for Mil grade 1-MNN are given in Ref 35 Flash Point. Closed Cup, 327°F (Ref 42)... 

Ignitability-flammability. A liquid that has a flash point of less than 60°C (140°F) is considered ignitable. Some examples are benzene, hexane, heptane, benzene, pentane, petroleum ether (low boiling), toluene, and xylene(s). 

Inspection of the table discloses that the flash point is 40 F for toluene. Since the temperature of the process vessel contents exceeds the flash point for toluene, the vapor is flammable. This is shown below ... 

Cumene is a colorless liquid, soluble in benzene and toluene and insoluble in water. It can be shipped in tank cars, tank trucks, barges, and drums. The flash point is high enough that it is not considered a hazardous material, and no DOT red shipping label is required. 

Toluene is a colorless, flammable liquid with a benzene-like odor, bp 110.8°C, flash point 4.4°C, ignition temperature 552°C, and TLV (TWA) = 50 ppm. 

Toluene (C6H5CH3, boiling point 110.8°C, density 0.8548, flash point 4.4°C, ignition temperature 552°C) is a colorless, flammable liquid with a benzenelike odor that is essentially insoluble in water but is fully miscible with alcohol, ether, chloroform, and many other organic liquids. Toluene dissolves iodine, sulfur, oils, fats, resins, and phosgene. When ignited, toluene burns with a smoky flame. Unlike benzene, toluene cannot be easily purified by crystallization. 

A flammable chemical substance is a solid, liquid, vapor, or gas that ignites easily and burns rapidly in air. Many of the flammable chemicals used in laboratories are flammable liquids and organic solvents. The vapors of these chemical substances form ignitable mixtures with air. Based on the flash points of these chemicals, classifications are made. The flash point of a chemical substance is defined as the lowest temperature at which a fuel-air mixture present above the surface of a liquid will ignite, if an ignition source is present. The common flammable chemical substances include, but are not restricted to, acetone, benzene, cyclohexane, ethanol, ethyl acetate, ethyl ether, gasoline, hexane, isopropyl alcohol, methanol, propanol, tetrahydro-furan and toluene, and xylene. 

Hydrocarbon Solvents. Most hydrocarbon solvents are mixtures. Few commercial hydrocarbon solvents are single compounds. Toluene is an exception. Hydrocarbon solvents are usually purchased and suppHed on specification. The most important specification properties are distillation range, solvency as expressed by aniline cloud point and Kauri-Butanol (KB) value, specific gravity, and flash point. Composition requirements such as aromatic content and benzene concentration are also important in many appHcations. 

Safety advantages Lower toxicity than toluene and methylene chloride, LD50 17.4gkg- Low vapour pressure, <0.1 mmHg High flash point, > 182 °C... 

The most widely used primary solvent is toluene. Other primary solvents are p-, m-, and mixed xylene. Pseudocumene (1,2,4-trimethyl benzene) is becoming a popular solvent for new, commercially produced scintillation cocktails. It offers the highest energy conversion efficiency of the solvents known, and has fewer restrictions on shipping and storage of a combustible liquid because of its high flash point, low volatility and lower toxicity. 

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