Rubbing alcohol is the common name for isopropyl alcohol, also called isopropanol. This compound is chemically related to ethanol, or drinking alcohol; however, unlike ethanol, it should not be consumed recreationally. Depending upon the context in which it's used and how it's used, rubbing alcohol has several potential effects -- ranging from the toxic to the helpful.
It's irritating to the skin in some sensitive individuals, mostly because it's very drying. In the eyes, isopropanol stings and causes redness. Inhaled, the compound can irritate the lungs, leading to coughing and, in very high concentrations, to lethargy or dizziness. Finally, if taken internally, isopropanol can cause symptoms of intoxication and lethargy, eventually leading to death. Most adults experience symptoms of toxicity with ingestion of only a few teaspoons of the compound, and 8 ounces is sufficient to cause death in most individuals. If taken internally or inhaled in large quantities, the chemical has the potential to be toxic, says the Material Safety Data Sheet for isopropanol.
One of the most useful effects of rubbing alcohol is that it can kill bacteria, viruses and fungi. For this reason, it's a common disinfectant, notes Ohio State University. Hospitals and health clinics typically apply it to the skin on a swab prior to administering an injection or inserting an intravenous needle. Rubbing alcohol is used to clean the skin and piercing instruments before piercing ears or other body parts, and it is often used in hospitals to swab floors and surfaces. The alcohol disrupts cell structures of bacteria and other pathogens, killing them on contact.
Prevention of Swimmer's Ear
Yet another useful effect of rubbing alcohol is that it may prevent "swimmer's ear." This is an irritating infection of the ear canal that results from bacterial or fungal growth in a chronically moist ear. Rubbing alcohol mixes with water and is much more volatile than water, meaning it evaporates more easily than water. Therefore, when rubbing alcohol is poured into the ear, it can help get rid of accumulated water. This treatment dries the ear canal and makes it a less hospitable environment for bacteria and fungus, reports CNN Health. Further, the alcohol can disinfect the ear, killing already present pathogens.