Dichloromethane paint stripper

One of the chief uses of chloromethane is as a starting material from which sili cone polymers are made Dichloromethane is widely used as a paint stripper Trichloromethane was once used as an inhalation anesthetic but its toxicity caused it to be replaced by safer materials many years ago Tetrachloromethane is the starting mate rial for the preparation of several chlorofluorocarbons (CFCs) at one time widely used as refrigerant gases Most of the world s industrialized nations have agreed to phase out all uses of CFCs because these compounds have been implicated m atmospheric processes that degrade the Earth s ozone layer... 

A liquid not considered flammable may still have an explosive potential. An example is dichloromethane or methylene chloride, often used in paint strippers, which evaporates very quickly. It is not flammable, but its vapors may be explosive (explosive limits 12% to 22%). 

These incombustible substances are halogenous derivatives whose extinction properties are well known and some molecules were used as extinction agents before it was realised they were toxic. Paint stripper containing methanoi and dichloromethane... 

Also known as DCM or dichloromethane. Often used as an adhesive solvent for acrylics. Pure DCM can be found in craft stores. DCM must be distilled first from all non-flammable paint strippers beforehand (they contain a paste that holds several unwanted substances.) The paint stripper may also contain methanol (most marine grade paint strippers are 80-90% DCM. Methanol is also an organic solvent. DCM distills at 47° C or 116° F. Pure DCM is best. May cause cancer and blindness. Take necessary precautions. Methylene chloride sinks to the bottom of the jar. 

Most of the current applications of dichloromethane are based on its solvent properties. For use in paint strippers, one of its first applications, dichloromethane is blended with other chemical components to maximize its effectiveness against specific coatings. Typical additives include alcohols, acids, amines or ammonium hydroxide, detergents and paraffin wax (Rossberg et al., 1986 Holbrook, 1993 WHO, 1996). 

A large do-it-yourself consumer population uses paint strippers containing dichloromethane on furniture and woodwork. Formulations are available mainly in liquid form, but also, occasionally, as an aerosol. Exposures have been estimated on the basis of investigations of the use of household liquid products in the United States. The estimated levels ranged from less than 35 mg/m- to a few short-term exposures of 14 100— 21 200 mg/mC The majority of the concentration estimates were below 1770 mg/ni (WHO, 1996). 

Many of these so-called halogenoalkanes are used as solvents. For example, dichloromethane is used as a solvent in paint stripper (Figure 14.6). 

Figure 14.6 Dichloromethane is used as a solvent in paint stripper.

European Commission Expert Team for Vapour Retarding Additives Effectiveness of Vapour Retardants in Reducing Risks to Human Health from Paint Strippers containing Dichloromethane, Final Report published by the European Commission, Brussels, Belgium, 2004. 

Paint strippers are also formulated to have high viscosity, otherwise they run olf vertical surfaces and thereby fail to penetrate or solubilise the paint to which they have been applied. Hydroxypropyl methylcellulose is the main thickener for paint strippers, which use methylene chloride (dichloromethane) as the principal component. Hydroxypropyl methylcellulose is useful for this purpose because it is soluble in the organic component but is not sensitive to the presence of any water that may also be present in the paint stripper. 

Finally, another halogenated solvent that causes toxic effects after acute exposure is dichloromethane or methylene chloride. It is used for degreasing engines and metalwork, and is the main constituent of paint stripper. If it is used in confined, enclosed spaces, such as rooms without adequate ventilation, it can lead to serious, unexpected toxic effects. As the solvent is breathed in by the worker it becomes localized in body fat. Later the... 

Dichloromethane is commonly used as a degreaser and a paint stripper. It is metabolized in the liver by the cytochrome p-450 pathway to produce carbon monoxide. An independent pathway of metabolism occurs via conjugation with glutathione. Animal experimentation has demonstrated hepatotoxicity at near lethal concentrations of dichloromethane. Dichloromethane potentiates carbon tetrachloride hepatotoxicity in rat livers. Short term exposure to both ethanol and dichloromethane demonstrate an antagonistic relationship, while chronic exposure potentiates hepatotoxicity. ... 

Terpene, d-limonene, was selected for cleaning oil spills and waste petroleum products (e.g., tar or grease). The combination of l-methyl-2-pyrrolidone with d-limonene makes a good paint stripper. It eliminates dichloromethane and other undesirable solvents. 

Methylene chloride (dichloromethane, methylene dichloride) n. CH2-CI2. A low-boiling chlorinated hydrocarbon which is a colorless, fairly dense, non-flammable liquid used as a solvent for cellulose triacetate and vinyl resins, a solvent in the polymerization of polycarbonate resins, and as a reactant for certain phenolic resins. It was widely used as a paint stripper and solvent for cured epoxy resins, but is less used now in the effort to keep chlorinated solvents... 

CH2C12 Dichloromethane (methylene chloride) Paint strippers 40... 

Dichloromethane is a volatile liquid with excellent solvent properties for nonpolar organic solutes. It has been used as a solvent for the decaffeination of coffee, in paint strippers, as a blowing agent in urethane polymer manufacture, and to depress vapor pressure in aerosol formulations. Once commonly sold as a solvent and stain remover, highly toxic carbon tetrachloride is now largely restricted to... 

Methylene chloride, also known as dichloromethane, evaporates easily, but does not burn easily. It does not appear to occur naturally in the environment. It is made from methane gas or wood alcohol. As noted it is widely used as an industrial solvent and as a paint stripper as well as in the manufacture of photographic film. The chemical may be found in a variety of household products including spray paints, automotive cleaners and some pesticide formulations. 

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