Xylene flash point

A2.2 Specifications for p-Xylene Flash Point Check Grade... 

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... 

The flash point of a liquid is the minimum temperature at which its vapor pressure is sufficiently high to produce a flammable mixture with air above the liquid. Therefore, the generation of a flammable gas or vapor cloud for liquids whose flash points are above the ambient temperature, e.g., xylene (see Table 3.1), is only possible if they are released at elevated temperatures or pressures. In such... 

Physico-chemical standards benzoic acid with a stated melting point, p-xylene with a stated flash point, sand with a quoted particle size distribution and polymers with quoted molecular weight distributions. 

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). 

Xylene CAS number UN number Classification Hazard class TSCA Flash point, PMCC OSHA PEL Vapor pressure 1330-20-7 UN 1307 Flammable liquid 3 Reported in TSCA inventory 83°F (28°C) TWA 100 ppm STEL 150 ppm 6.72 mmHg 70°F (21°C)... 

Make determinations in triplicate on the flash point of standard p-xylene and of standard isopropyl alcohol which meet specifications set forth in Appendix A2. Average these values for each compound. If the difference between the values for these two compounds is less than 15 F (8.5 C) or more than 27 F (l6 C), repeat the determinations or obtain fresh standards (Note 7)... 

If desired, one could replace CCI4 with hexane (a mixture of several isomers), since hexane is not very toxic and has an exposure limit of 100 ppm vapor in the air. However, hexane is more volatile, and the distribution constant for I2 is different in different hexane isomers, leading to problems with the data analysis. Perhaps a better alternative is p-xylene. Although less toxic this solvent is however more flammable than CCI4, with a flash point of 17°C. Finally, we note that it is also possible to determine I2 concentrations spectrophotometrically, which eliminates the titrations. 

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. 

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. 

Includes ethyl benzene and isomers of xylene. Melting point, flash point, and azeotropic characteristics will vary slightly with composition. Sources ... 

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