Refrigerators explosion-proof

Some chemicals may need refrigerated storage because of high vapor pressure. If the vapors are flammable, an explosion-proof refrigerator is mandatory, despite its high cost. 

In a cold bath or in an explosion-proof refrigerator, a solution of 1.3 gm (approximately 0.0035 mole) of crude Y,Y -benzhydrylhydrazine (m.p. 114°-130°C) in a mixture of 40 ml of acetone and 50 ml of ethanol and 1.25 gm (0.0096 mole) of 30% hydrogen peroxide is maintained at 10°-15°C for 8 hr. The solvent is rapidly removed by evaporation under reduced pressure with only moderate warming. The residue is rapidly recrystallized from ethanol. Yield 1 gm (76%), m.p. 115°C dec. (NOTE On melting, azobis(diphenyl-methane) decomposes with loss of nitrogen to form a solid with m.p. 205°-210°C, which has been identified as the expected 1,1,2,2-tetraphenylethane.)... 

Chemicals should be stored properly. For example, flammable chemicals (e.g ethanol, methanol, acetone, methyl ethyl ketone, petroleum distillates, toluene, benzene, and other materials labeled flammable) should be stored in approved flammable storage cabinets, and flammable chemicals requiring refrigeration should be stored in explosion-proof refrigerators. Oxidizers should be segregated from other chemicals, and corrosive acids (e.g., sulfuric, hydrochloric, nitric, perchloric, and hydrofluoric acids) should also be stored in a separate cabinet, well-removed from the flammable organics. 

Only use an explosion-proof refrigerator for chemical storage. 

Aerosol cans containing flammable substances must be stored in FM-approved or UL-listed flammable liquid storage cabinets. Flammable liquids must be stored in flammable liquid storage cabinets or explosion-proof refrigerators rather than fume hoods. 

Hazardous Decomp. Prods. ffeated to decomp., emits toxic fumes of HCI gas, CO, CO2, phosgene emits toxic fumes under fire conditions NFPA ffealth 2, Flammability 3, Reactivity 2 Storage Air-, light-, and moisture-sensitive keep container tightly closed under Inert atmosphere store In explosion-proof refrigerator protect from light... 

Langan,JP., Questions [Pg.273]

Storage Keep container tightly closed under inert atmosphere store in explosion-proof refrigerator protect from light store away from ignition sources Uses Organic synthesis military poison gas explosive... 

Storage Moisture-sensitive store in tightly closed container under inert atmosphere in explosion-proof refrigerator store away from ignition sources... 

Hazardous Decomp. Prods. Heated to decomp., emits toxic fumes of CO, CO2, POx, phosphine Storage Store in explosion-proof refrigerator storage under inert atmosphere rec. moisture-sensitive protect from moisture store away from ignition sources... 

Storage Store in explosion-proof refrigerator Uses Explosive compositions organic synthesis... 

FIGURE 7.3.1.1 Explosion-Proof Refrigerator for Laboratories. These refrigerators are usually hard-wired into electrical supplies (so that they cannot accidentally become unplugged) and they have spark-proof interiors (internal switches and lights have been removed.)... 

Use purified and freshly distilled solvents only. Methanol and ethanol are distilled over potassium hydroxide to remove aldehydes. It is particularly important that only freshly distilled chloroform be used. Peroxides can be removed from diethyl ether by distilling over hydroxylamine or ferrous sulphate it is kept over iron or sodium wire. Both chloroform and ether are best stored in an explosion-proof refrigerator. Petrol ether should be distilled over concentrated sulphuric acid. 

Acids should be stored in cabinets made of plastic or wood, as described in Section 8.2.1. Reactive materials must be stored in a cool dry place out of direct sunlight. Water-reactive materials should not be stored directly under fire-sprinklers ( ) and there may be code requirements for these compounds. Some compounds, such as organic peroxides, may need to be stored under refrigerated conditions and it is imperative that these only be stored in spark-proof or explosion-proof refrigerators. Conversely, it may increase the hazard if some organic peroxides are stored at too low a temperature. Therefore, it is important to adhere to the recommended storage requirements for specific reactive chemicals. 

Figure 16.6 Explosion-proof refrigerator. (Courtesy of Lab-Line Instruments, Inc.)...

Lack of safety storage cans and safety storage cabinets Lack of explosion-proof refrigerators where required Improper storage and labeling of carcinogenic compounds... 

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