Dichloromethane is insoluble in water, but soluble in phenol, aldehyde, ketone, glacial acetic acid, triethyl ester of phosphoric acid, ethyl acetoacetate, cyclohexylamine. Pyrolysis produces HCl and traces of phosgene, heating with water for a long time will generate formaldehyde and HCl. Further chlorination can get CHCl3 and CCl4. Methylene chloride with sodium hydroxide reactions and partially hydrolyzed to produce formaldehyde at high temperature. Dichloromethane produced by natural gas reacts with chlorine gas in industry. Then after distillation to be purified.
It is an excellent organic solvents and commonly used to replace the flammable petroleum ether, ethyl ether. It can be used as dental local anesthetic, refrigerants and fire extinguishing agent, etc. The irritation to the skin and mucous membranes slightly stronger than chloroform, so it should pay attention to the use of the high concentration of dichloromethane.
Dichloromethane has a strong dissolve and low toxicity. It mostly used to manufacture film, polycarbonate, as well as metals degreaser, paint solvents, gas and smoke spray aerosol, polyurethane foam, mould release agents, paint remover.
Dichloromethane is colorless liquid and is used as reaction medium in the pharmaceutical industry. It also can be used for the preparation of ampicillin, carbenicillin, oil dewaxing solvent, aerosol propellant, synthetic organic extractant, polyurethane foam used for the production of foaming agent and metal cleaning agent, etc. It used as an auxiliary blowing agent in the production of polyether Urethane foam, as well as the blowing agent of extruded PS foam. Meanwhile, dichloromethane is a substance used to make decaffeinated coffee. Through the cooking to make the caffeine dissolves and float on the surface, then use dichloromethane to remove the caffeine.
Vapor of dichloromethane has narcotic effect. It mainly damage the central nervous and respiratory systems. Human major exposure way is inhalation. When it comes across a severe danger of poisoning, it should immediately disengage and move to fresh air, some symptoms will be relieved or disappear without causing lasting damage.
At the same time, here is the protection and first aid measures:
Respiratory protection: when the concentration is beyond the standard in the air, direct gas masks should be worn (half masks). Wear air respirator when emergency rescue or evacuation.
Eye protection: wear chemical safety goggles if necessary.
Body protection: wear antivirus penetration overalls.
Hand protection: wear chemical-proof gloves.
Besides, no smoking, eating, and drinking water in the workplace. Take a shower after work, and separate the contaminated clothing. OKCHEM blog updates knowledge and information about chemicals and precise datas of China chemicals, if you have interest, please follow us on linkedin or visit OKCHEM.COM.