Hazards, explosive, methyl

Dokter, T., Explosion hazards of methyl chloride and chlorine-containing systems, PhD thesis, Twente University, Netherlands. 1987... 

The choice of the manufacturing process should involve consideration of all the materials involved in the total process and not just those involved in the chemical synthesis step alone. A process that used methanol as solvent had an effluent treating facility downstream a cheap option was treating the waste with sodium hypochlorite solution. However, it was realized that the residual methanol in the effluent would react with the hypo to produce the dangerous impact-sensitive explosive, methyl hypochlorite. So an alternate, methanol-free process had to be developed to avoid the hazard downstream. 

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. 

Organic Peroxides — (R-O-O-R) are very hazardous. Most of the compounds are so sensitive to friction, heat, and shock that they cannot be handled without dilution. As a result, organic peroxides present a serious fire and explosion hazard. Commonly encountered organic peroxides include benzoyl peroxide, peracetic acid, and methyl ethyl ketone peroxide. 

The next simplest ether is the ether with the simplest alkane as one of the hydrocarbon backbones and the next alkane, which is methyl ethyl ether. Its molecular formula is CH3OC2H5. It is a colorless gas with the characteristic ether odor. It has a flash point of 31 °F, and an ignition temperature of only 374°F. This property, of course, makes it an extreme fire and explosion hazard. 

The chlorination of methyl chloroformate in sunlight was first reported by Hentschel, but without a detailed description of either the procedure or the results. The first step of the present procedure for the preparation of trichloromethyl chloroformate utilizes an ultraviolet light source and affords a simple and reproducible way to obtain this reagent. Although trichloromethyl chloroformate may also be synthesized by photochemical chlorination of methyl formate,the volatility of methyl formate causes losses during the reaction and increases the hazard of forming an explosive mixture of its vapor and chlorine gas. The preparation of trichloromethyl chloroformate by chlorination of methyl chloroformate in the dark with diacetyl peroxide as initiator has been reported. However, the procedure consists of several steps, and the overall yield is rather low. 

Dream reactions can be performed using chemical micro process engineering, e.g., via direct routes from hazardous elements [18]. The direct fluorination starting from elemental fluorine was performed both on aromatics and aliphatics, avoiding the circuitous Anthraquinone process. While the direct fluorination needs hours in a laboratory bubble column, it is completed within seconds or even milliseconds when using a miniature bubble column. Conversions with the volatile and explosive diazomethane, commonly used for methylation, have been conducted safely as well with micro-reactors in a continuous mode. 

In the Diels-Alder condensation of the 2 neat endothermic dienes to give 5-ethylidene- and 5-methyl-6-methylene-bicyclo[2.2.1]hept-2-ene, there is a serious risk of explosive decomposition arising from local overheating of the reactor walls. This hazard is eliminated by the presence of various hydrocarbons and their mixtures as diluents. 

Temperature control during pressure hydrogenation of cis- or tram-isomers is essential, since at 155°C violent decomposition to carbon, hydrogen and carbon monoxide with development of over 1 kbar pressure will occur. The material should not be heated above 100°C, particularly if acid or base is present, to avoid exothermic polymerisation [1], The m-isomer is readily cyclised to 2,3-dimethylfuran, which promotes lire and explosion hazards. These were measured for the cis- and tram-isomers, and for fram-3-methyl-l-penten-4-yn-3-ol [2],... 

The latent hazards in storing and handling the explosive mixtures with the cone, acid are discussed (methyl nitrate may be formed). 

Some chemicals are susceptible to peroxide formation in the presence of air [10, 56]. Table 2.15 shows a list of structures that can form peroxides. The peroxide formation is normally a slow process. However, highly unstable peroxide products can be formed which can cause an explosion. Some of the chemicals whose structures are shown form explosive peroxides even without a significant concentration (e.g., isopropyl ether, divinyl acetylene, vinylidene chloride, potassium metal, sodium amide). Other substances form a hazardous peroxide on concentration, such as diethyl ether, tetrahydrofuran, and vinyl ethers, or on initiation of a polymerization (e.g., methyl acrylate and styrene) [66]. 

Thermal decompositions of alkyl azides are advantageously studied in millimole quantities using a PE spectroscopically controlled flow system under low pressure ( ), thereby reducing the hazards involved in handling these explosive compounds in bulk. Our investigations started with methyl azide, which splits off nitrogen unexpectedly only at temperatures above 500° C (37) ... 

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