Isopropyl alcohol is a colorless, combustible liquid known by a variety of other names. For instance, in the laboratory it may be labeled as isopropanol, isopro, iso, isopropyl, or simply by the acronym IPA. It is also sometimes called 2-propanol, likely in reference to being an isomer of an inorganic compound known as propanol. Of course, isopropyl alcohol is most commonly known as simple rubbing alcohol.

Isopropyl alcohol is classified as being a secondary alcohol, meaning that the carbon atom that makes up the alcohol component is bound to two other carbon atoms. As such, isopropyl alcohol can be reduced by oxidation, which, in this case, yields the solvent acetone. Although isopropyl alcohol is made from combining water with propylene, it can be easily separated from its water constituent though a process called salting out. This involves the addition of an organic salt, such as sodium chloride.

Other than providing an outlet for chemical experimentation in the lab, isopropyl alcohol can be found in nearly any home medicine cabinet. In fact, isopropyl alcohol was once the popular choice for medicinal rubdowns—hence the nickname of rubbing alcohol. When applied to the skin, the water content quickly evaporates, cooling the skin’s surface and rapidly reducing body temperature. For this reason, it was once recommended for reducing fever in children. However, since rapid decrease in temperature is now considered detrimental, medical professionals no longer recommend the use of isopropyl alcohol for this purpose.

Although isopropyl alcohol is commonly used in the home as an antiseptic for cuts and scrapes, it is not a harmless substance. For one thing, it is highly combustible in the presence of high heat or an open flame. It can even explode when exposed to air or light due to the formation of peroxides. It is also now recognized that isopropyl alcohol is readily absorbed through the skin and may have harmful systemic effects. If ingested, isopropyl alcohol is highly toxic and may even be fatal.

Since isopropyl alcohol is a solvent, it has many uses as a cleaning agent, providing safety precautions are observed. For instance, computer users know the value of this substance in removing dirt from hard to reach areas, such as between keys on keyboards and on mouse wheels. In fact, since it evaporates almost immediately, there is little risk of shock or damage to electrical components. Isopropyl alcohol also removes stubborn glue residue, as well as dried ink. Music shop owners commonly give new life to used vinyl records by wiping them with a soft cloth moistened with a small amount of isopropyl alcohol.

Isopropyl alcohol is also a component of additives intended to prevent or treat water accumulation in fuel lines, such as “dry gas.” In fact, it helps to reduce the risk of water freezing in fuel lines. It does this by making the water soluble, which would otherwise separate from the gasoline and turn to ice during cold weather.