Benzene, flash-point

Benzotricbloride [(tricblorometbyl)benzene, a,a,a-trichlorotoluene, phenylchloroform], C H CCl, is a colorless, oily Hquid with a pungent odor. It is soluble in most organic solvents, but it reacts with water and alcohol. For ben zotricbl oride the flash point is 127°C (Cleveland open cup) and the autoignition temperature is 211°C (8). 

Special additives are often included in a carrier formulation to provide specific properties such as foam control, stabiUty, and fiber lubrication during dyeing. Most important are the solvents used to solubilize the soHd carrier-active chemicals. These often contribute to the general carrier activity of the finished product. For example, chlorinated benzenes and aromatic esters are good solvents for biphenyls and phenylphenols. Flammable compounds (flash point below 60°C) should be avoided. 

Compounds with low flash points (below room temperature). Examples are acetaldehyde, acetone, acetonitrile, benzene, carbon disulfide, cyclohexane, diethyl ether, ethyl acetate and -hexane. 

Incidentally, MTBE also forms an azeotrope with H2O (like benzene does), so there is no need to dry it over MgSC>4 or 4 A molecular sieves after an extraction, as must be done with both ether and THF. MTBE also has a much higher flash point than ether. 

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). 

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. 

Benzene is a clear, colorless, flammable liquid with a pleasant characteristic odor, bp 80.1°C, flash point -11.1°C, and ignition temperature 538°C. Benzene has been found to be very toxic and is on the list of Known to Be Human Carcinogens published every two years by the Department of Health and Human Services under the National Toxicology Program (NTP). There are four top 50 chemicals on this worst carcinogen list benzene 1,3-butadiene ethylene oxide and vinyl chloride. There are also four chemicals in the top 50 on the Reasonably Anticipated to Be Human Carcinogens list acrylonitrile, ethylene dichloride, formaldehyde, and propylene oxide. 

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. 

The British, French Italians during WWII used mixtures of heavy and light petroleum distillates with a density of about 0.86 at 15°. The Germans used various mixtures of petroleum distillates, coal tar fractions, and sometimes such liquids as methanol, acetone or even ether. The density of such mixtures was usually about 0.96 at 15°. One of the first American mixtures contained 70% water-gas tar (flash point 122° and d 1,044) and 30% "benzene heads (fl p 26° and d 0.756). The resulting mixture had d 1.02. 

Flash point (+) 36°C (-) 34°C Soluble in ether, hydrocarbons, chloroform, benzene, ethanol etc. ... 

Benzene s molecular formula is C6H6, but it does not behave like hexane, hexene, or any of their isomers. One would expect it to be similar to these other six-carbon hydrocarbons in its properties. Table 4 provides a comparison between benzene, hexane and 1-hexene. The table shows that there are major differences between benzene and the straight-chain hydrocarbons of die same carbon content. Hexene s ignition temperature is very near to hexane s. The flash point difference is not great, however, there are significant differences in melting points. The explanation for these differences is structure which in the case of benzene is a cyclical form with alternating double bonds. 

Benzene Hexachloride — Rre Hazards Flash Point (deg. F) Not flammable Flammable Limits in Air (%) Not flammable Fire Extinguishing Agents Not pertinent Fire Extinguishing Agents Not To Be Used Not pertinent Special Hazards of Combustion Products Toxic gases are generated when... 

Benzene Phosphorous Thiodichloride — Fire Hazards Flash Point (deg. F) 252 OC ... 

Dibydroxybenzene, Resorcinol or 1,3-Ben-zenediol (called 1.3-Dioxy-benzol or Resorcin in Ger), white orthorhombic crysts (from water, ale or acet), mp 110.7°, bp 281° d 1.2717 flash point (open cup) 339° F sol in w, ale, ether, glycerol, benzene and amyl ale si sol in chlf less toxic than the 1,2-deriv but con-tact with skin sp.d ip.hslsticn of dust should... 

Benzene (C6H6, boiling point 80°C, density 0.8789, flash point -11°C, ignition temperature 538°C), is a volatile, colorless, and flammable liquid aromatic hydrocarbon possessing a distinct, characteristic odor. Benzene is practically insoluble in water (0.07 part in 100 parts at 22°C) and fully miscible with alcohol, ether, and numerous organic liquids. 

Cumene (Ao-propyl benzene, boiling point 152.4°C, density 0.8619, flash point 44°C) is an important intermediate in the manufacture of phenol and acetone. 

Cyclohexane (hexahydrobenzene, melting point 6.5°C, boiling point 81°C, density 0.7791, flash point -20°C) can be quantitatively produced from benzene by hydrogenation over either a nickel or a platinum catalyst at 210°C and 350 to 500 psi hydrogen (Fig. 1). 

Ethylbenzene (boiling point 136°C, density 0.8672, flash point 21°C) is a colorless liquid that is manufactured from benzene and ethylene by several modifications of the older mixed liquid-gas reaction system using aluminum chloride as a catalyst (Friedel-Crafts reaction). The reaction takes place in the gas phase over a fixed-bed unit at 370 C under a pressure of 1450 to 2850 kPa. Unchanged andpolyethylated materials are recirculated, making a yield of 98 percent possible. The catalyst operates several days before requiring regeneration. 

Maleic anhydride (melting point 52.8°C, boiling point 202°C, flash point 110°C), formerly made from benzene, is now made from butane (Figs. 1 and 2) a switch in manufacturing method that was very rapid and complete. 

Naphthalene (melting point 80.3°C, density 1.175, flash point 79°C) is very slightly soluble in water but is appreciably soluble in many organic solvents such as 1,2,3,4-tetrahydronaphthalene (tetralin), phenols, ethers, carbon disulfide, chloroform, benzene, coal-tar naphtha, carbon tetrachloride, acetone, and decahydronaphthalene (decalin). 

Nitrobenzene (melting point 5.9°C, boiling point 210.9°C, density 1.199, flash point 88°C) is made by the direct nitration of benzene using a nitric acid-sulfuric acid mixture (Fig.l), usually in a cast-iron or steel kettle. 

Phenol (hydroxybenzene freezing point 40.9°C, boiling point 181.8°C, density 1.0722 flash point 79°C) at room temperature is a white, crystalline mass. Phenol gradually turns pink if it contains impurities or is exposed to heat or light. It has a distinctive sweet, tarry odor, and burning taste. Phenol has limited solubility in water between 0 and 65°C. Above 65.3°C, phenol and water are miscible in all proportions. Phenol is very soluble in alcohol, benzene, chloroform, ether, and partially disassociated organics in general, but it is less soluble in paraffinic hydrocarbons. 

Styrene (phenyl ethylene, vinyl benzene freezing point -30.6°C, boiling point 145°C, density 0.9059, flash point 31.4°C) is made from ethylbenzene by dehydrogenation at high temperature (630°C) with various metal oxides as catalysts, including zinc, chromium, iron, or magnesium oxides coated on activated carbon, alumina, or bauxite (Fig. 1). Iron oxide on potassium carbonate is also used. 

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. 

Jet fuel JP-8 (jet propellant-8) is a kerosene-based distillate selected by the U.S. Air Force to replace JP-4 and other predecessors, which were replaced because JP-8 has a higher flash point, is composed of higher chain hydrocarbons, and does not contain benzene. Profiles for JP-8 list the following classes of compounds exclusive of additives alkanes (43% by weight) cycloalkanes (11%) alkylbenzenes (12%) naphthalenes (2%) and dicycloparaffins, tetralins, and olefins (% not specified) (USAF 1991). A more detailed list of hydrocarbon components is given in Table A-l. 

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. 

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