2-Butanone is a manufactured organic chemical but it is also present in the environment from natural sources. It is a colorless liquid with a sharp, sweet odor. It is a ketone, also known as methyl ethyl ketone (MEK).
2-Butanone is produced in large quantities. Nearly half of it is used is in paints and other coatings because it will quickly evaporate into the air and it dissolves many substances. It is used as a solvent in processes involving gums, resins, cellulose acetate and cellulose nitrate. It is also used in the synthetic rubber industry, in the production of paraffin wax and in household products such as lacquer, varnishes, paint remover and glues and as a cleaning agent. It is highly flammable and is not considered a large health threat.
2-Butanone occurs as a natural product. It is made by some trees and found in some fruits and vegetables in small amounts. It is also released to the air from car and truck exhausts.
The known health effects to people from exposure to 2-butanone are irritation of the nose, throat, skin, and eyes. No one has died from breathing 2-butanone alone. If 2-butanone is breathed along with other chemicals that damage health, it can increase the amount of damage that occurs.
Serious health effects in animals have been seen only at very high levels. When breathed, these effects included birth defects, loss of consciousness, and death. When swallowed, rats had nervous system effects including drooping eyelids and uncoordinated muscle movements. There was no damage to the ability to reproduce.
Mice who breathed low levels for a short time showed temporary behavioral effects. Mild kidney damage was seen in animals that drank water with lower levels of 2-butanone for a short time.
There are no long-term studies with animals either breathing or drinking 2-butanone.
US EPA Datasheet
US NIH List of Products That Contain Butanone (MEK)