Butanone is a manufactured chemical that is also present in the environment from natural sources. It is a colorless liquid with a sharp, sweet odor. It is also known as methyl ethyl ketone (MEK). 2-Butanone is produced in large quantities. Nearly half of its use is in paints and other coatings because it quickly evaporates into the air and dissolves many substances. It is also used in glues and as a cleaning agent. 2-Butanone occurs as a natural product. It is made from some trees and found in some fruits and vegetables in small amounts. It is also released into the air from car and truck exhausts.