Acetone is a colourless, flammable liquid. Because acetone is miscible (forms a homogenous solution) with water and most organic fluids, it is an important solvent, typically for cleaning purposes in a laboratory. More than 3 million tonnes are produced annually, mainly as a base compound for making polymers (plastics, for example). Acetone is the active ingredient in many nail polish removers (often highlighted on the label due to its powerful odour). Many nail polish manufacturers now use non-acetone removers due to potential skin-related concerns (dermatitis, eczema) with acetone.