Flash point explosion

Mists are dust clouds in which the particles happen to be liquid. Should that liquid be combustible, even though it is nowhere near its flash-point, explosion is possible. 

Mists are dust clouds in which the particles happen to be liquid. Should that liquid be combustible, even though it is nowhere near its flash-point, explosion is possible [1] [2]. Mist explosions attract increasing study [3]. It is possible that many vapour cloud explosions have had a mist component. The editor surmises that, under appropriate circumstances, evaporation of volatile mist by the heat of a vapour (or mist) explosion might generate a larger pressure pulse than simple thermobaric effects on air. Foams are inverse mists and should show similar explosive potential. 

Bond, J., Sources of Ignition (Oxford Butterworth, 1991) (flash points, explosive limits, and autoignition temperatures). 

One of the most important aspects in the intermediate field is to determine and make known safe handling techniques for your products. Many intermediates have an element of hazard in their use. The supplier generally takes upon himself the determination of such data as flash point, explosive properties, and toxicology and publishes them in a manual. Here, unlike the field of performance chemicals, suppliers frequently pool their information to give their user the benefit of broader experience and more detailed data. Oftentimes, manuals of this type are published by such organizations as the Manufacturing Chemists Association for the entire industry. 

For most of the compounds no data are reported for basic properties, such as odor threshold, flash point, explosive limits, decomposition temperature, etc. 

In addition to the chemical exposure, fire, and explosion, the various factors considered in the Mond Index are the material factor and its associated hazards, process hazard, quantity hazard, layout hazard, and toxicity hazard. The material factor relates to the type of materials, their flash point, explosive limits, etc., the nature of the process, and the process s inherent safety. The... 

Chemical Flash point. Explosive limits, % D.O.T. class TLV- TWA" Absorbed through skin Special hazards ... 

Table 1 lists the most important databases including information on chemical safety. The Contents column classifies the main contents of the database GEN = general information on chemical safety, NUM = numerical data for safety characteristics (for example flash points, explosion limits), TOX = toxicological data, CLA = classifications for transportation, handling and storage. If the term is shown in brackets, for example (NUM), the database has its main focus on a different topic, but data according to the term in brackets may be found there also. 

Proper shipping name Flash point Explosive LEL Explosive UEL... 

UN risk phrases, R UN safety phrases, S UN/NA class DOT class ADR/RIC class Autoignition temperature Flash point Explosive LEL Explosive UEL TLV-TWA8h, NIOSH TLV-TWA8h, OSHA... 

Petroleum solvents are very flammable and can cause an explosion in the presence of air. For this reason, their flash points, directiy related to volatility, are always specified. 

Carbon disulphide should never be used if any alternative solvent is available, as it has a dangerously low flash-point, and its vapours form exceedingly explosive mixtures with air. Ether as a solvent for recrystallisation is much safer than carbon disulphide, but again should be avoided whenever possible, partly on account of the danger of fires, and partly because the filtered solution tends to creep up the walls of the containing vessel and there deposit solid matter by complete evaporation instead of preferential crystallisation. 

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. 

Flash points and autoignition temperatures are given in Table 11. The vapor can travel along the ground to an ignition source. In the event of fire, foam, carbon dioxide, and dry chemical are preferred extinguishers. The lower and upper explosion limits are 1% and 7%. 

Flammability Acrolein is very flammable its flash point is <0° C, but a toxic vapor cloud will develop before a flammable one. The flammable limits in air are 2.8% and 31.0% lower and upper explosive limits, respectively by volume. Acrolein is only partly soluble in water and will cause a floating fire, so alcohol type foam should be used in firefighting. The vapors are heavier than air and can travel along the ground and flash back from an ignition source. 

The relatively low flash points of some acrylates create a fire hazard. Also, the ease of polymerization must be home in mind in ah. operations. The lower and upper explosive limits for methyl acrylate are 2.8 and 25 vol %, respectively. Corresponding limits for ethyl acrylate are 1.8 vol % and saturation, respectively. All possible sources of ignition of monomers must be eliininated. 

Formic acid is combustible (flash point = 69° C), but the explosive ha2ard is considered slight. The decomposition to CO requires appropriate precautions to be taken when entering tanks or other confined spaces that have contained the acid. 

Properties of the principal hydrocarbons found in commercial hexane are shown in Table 9. The flash point of / -hexane is —21.7 °C and the autoignition temperature is 225°C. The explosive limits of hexane vapor in air are 1.1—7.5%. Above 2°C the equiUbrium mixture of hexane and air above the Hquid is too rich to fall within these limits (42). 

Isoprene is classified by the ICC as a flammable Hquid requiring a red label (124). Its flash point is —54°C with a lower explosive limit (LEL) of 1.5%... 

Diketene is a flammable Hquid with a flash point of 33°C and an autoignition temperature of 275°C. It decomposes rapidly above 98°C with slow decomposition occurring even at RT. The vapors are denser than air (relative density 2.9, air air = 1). The explosive limits in air are 2—11.7 vol % (135). In case of fire, water mist, light and stabilized foam, as well as powder of the potassium or ammonium sulfate-type should be used. Do not use basic extinguisher powders and do not add water to a closed container. 

Physical Properties of Monomers. 1-Butene [106-98-9] is a colorless, flammable, noncorrosive gas its physical properties are fisted in Table 1, and its thermodynamic properties are available (16). Because 1-butene has a very low flash point, it poses a strong fire and explosion hazard. 

The lower flammable limit (LEL) or lower explosive limit (LEL) is the minimum concentration of vapor in air below which a flame is not propagated when an ignition source is present (61—64). Below this concentration, the mixture is considered too lean to bum. The lower flammable limit and the flash point of a flammable Hquid are closely related by the Hquid s vapor pressure characteristics. 

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). 

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.

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