Paint stripper, or paint remover, is a chemical product designed to remove paint, finishes, and coatings, while also cleaning the underlying surface. The product's material safety data sheet provides more safety information than its product labels. Paint can also be removed using mechanical methods (scraping or sanding) or heat (hot air, radiant heat, or steam). Types Chemical paint removers work only on certain types of finishes, and when multiple types of finishes may have been used on any particular surface, trial-and-error testing is typical to determine the best stripper for each application. Two basic categories of chemical paint removers are caustic and solvent. Caustics Caustic paint removers, typically sodium hydroxide (also known as lye or caustic soda), work by breaking down the chemical bonds of the paint, usually by hydrolysis of the chain bonds of the polymers forming the paint. Caustic removers must be neutralized or the new finish will fail prematurely. In addition, several side effects and health risks must be taken into account in using caustic paint removers. Such caustic aqueous solutions are typically used by antique dealers who aim to restore old furniture by stripping off worn varnishes, for example. Solvents Solvent paint strippers penetrate the layers of paint and break the bond between the paint and the object by swelling the paint. The active ingredient in the most effective paint strippers is dichloromethane, also called methylene chloride. Dichloromethane has serious health risks including death, is likely a carcinogen, and is banned in some countries for consumer use. Despite this, deaths from dichloromethane are extremely rare at less than 2.4 cases per year and associated mostly with users applying large amounts in confined, poorly ventilated spaces. When applied in reasonable amounts and with typical levels of ventilation, or outdoors, it is generally safe to use. Solvent strippers may also have formulations with limonene from orange peel (or other terpene solvents), n-methylpyrrolidone, esters such as dibasic esters (often dimethyl esters of shorter dicarboxylic acids, sometimes aminated, for example, adipic acid or glutamic acid), aromatic hydrocarbons, dimethylformamide, and other solvents are known as well. The formula differs according to the type of paint and the character of the underlying surface. Nitromethane is another commonly used solvent. Dimethyl sulfoxide is a less toxic alternative solvent used in some formulations. Unfortunately, these alternative stripping formulas are largely ineffective compared to those based on dichloromethane - removing only one layer at a