Solvents are liquid, gas, or solid chemicals that dissolve, extract, or suspend other substances. The most common and universal solvent is water, which dissolves more substances than any other.

Solvents are often categorized as polar or nonpolar, a factor of the solvent’s structure and charge that determines the types of substances it can dissolve. Polar solvents have a positive and a negative charge at different places in their structures and will dissolve other polar substances. Water, acetone, acetonitrile, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethanol, isopropanol, and methanol are examples of polar solvents.

Nonpolar solvents include alkanes (pentane, hexane, and heptane) and aromatics (benzene, toluene, and xylene). Other common nonpolar solvents include acetic acid, chloroform, diethyl ether, ethyl acetate, methylene chloride, and pyridine. Nonpolar organic solvents are used as spot removers, paint thinners, nail polish removers, glue solvents, and in perfumes and detergents.

Solvents are used extensively as a medium for chemical reactions and analytical separations and are available in various purity grades and packaging options. They are also essential for manufacturing cosmetics, pharmaceuticals, personal care items, textiles, paints, pesticides, and many other products.

Long-term exposure to some solvents can be hazardous to worker health. For example, chloroform and benzene, commonly found in gasoline, are considered carcinogenic. Solvents can also damage the liver, kidneys, nervous system, and brain. Chronic solvent-induced encephalopathy (CSE) is a known condition. Occupational exposure to organic solvents is also associated with alcoholism, cataracts, and the loss of hearing and color vision.