Acetone, chemically known as propanone (C3H6O), is the simplest ketone. This colorless, volatile liquid is familiar as the primary ingredient in most nail polish removers, but it also functions as a powerful industrial solvent. Acetone is found naturally in the environment and the human body, yet the vast majority of the product sold commercially is synthesized through industrial processes. Understanding the source of the acetone we use requires looking closely at both chemical manufacturing and biological metabolism.
Industrial Production Routes
Commercial acetone is petroleum-based because of the raw materials used for its production. Over 90% of the world’s acetone is synthesized using the Cumene process, which relies entirely on petrochemical precursors. This method starts with benzene and propylene, both of which are derived from the refining of crude oil and natural gas liquids.
The Cumene process is a two-step reaction that first combines benzene and propylene to create an intermediate compound called cumene. This cumene is then oxidized using air to form cumene hydroperoxide. The hydroperoxide is subsequently cleaved with an acid catalyst, yielding two co-products: phenol and acetone.
Because the feedstocks are direct products of the petroleum industry, the resulting commercial acetone is, by definition, petroleum-based. The process is mainly driven by the high demand for phenol, making acetone an economically important co-product. Although other methods exist, the Cumene process remains the dominant global source due to its efficiency and the dual market for both end products.
Acetone’s Role in Biology
Acetone is a natural metabolite in humans and animals, despite the industrial reliance on petroleum precursors. It is one of three compounds collectively known as ketone bodies, which the body produces when burning fat for energy instead of glucose. This metabolic state, known as ketogenesis, occurs primarily in the liver during fasting, prolonged exercise, or following a low-carbohydrate diet.
Ketogenesis involves the breakdown of fatty acids into acetyl-CoA, which is then converted into the ketone bodies acetoacetate and D-beta-hydroxybutyrate. Acetone is the third, less abundant ketone body, formed spontaneously from the non-enzymatic breakdown of acetoacetate. Unlike the other two ketone bodies, acetone cannot be used for energy and is excreted through the breath and urine.
The characteristic sweet or fruity smell detected on the breath of individuals in ketosis, such as those with uncontrolled diabetes, is due to the expulsion of this gaseous acetone. While acetone is a natural product of metabolism, the trace amounts found in the body or in natural sources are insignificant compared to the millions of tons produced annually by industry. This natural presence shows that the molecule itself is not inherently synthetic.
Everyday Uses and Basic Safety
Acetone is widely produced industrially because of its effectiveness as a solvent. The public most commonly encounters it in nail polish remover, where its ability to quickly dissolve lacquer is valued. It is also used in manufacturing as a solvent for plastics, lacquers, and adhesives, and as a degreasing agent in the textile industry.
The inherent flammability of acetone requires careful handling, as this volatile liquid can ignite easily, so it must be kept away from open flames. From a health perspective, acetone has a relatively low acute and chronic toxicity profile compared to many other solvents. The body processes small amounts due to its natural metabolic production, and its high volatility reduces the risk of significant accumulation.
To use acetone-containing products safely, ensure the area is well-ventilated to prevent the inhalation of high concentrations of vapor. Prolonged contact with the skin can lead to dryness because the solvent strips away natural oils. The U.S. Food and Drug Administration recognizes acetone as a generally safe substance for certain indirect food contact applications.