Although both are forms of alcohol, ethyl alcohol and Isopropyl alcohol have more differences than similarities. The differences begin at the sources they are made from. Ethel alcohol is most commonly derived from corn and isopropyl alcohol is derived from propene which can come from fossil fuels such as coal, petroleum or natural gas. Ethyl alcohol is subject to an excise tax by the federal government according to its percent proof. Isopropyl alcohol is only subject to sales tax.
Ethyl alcohol is alcohol for drinking and Isopropyl alcohol is alcohol for topical application. Ethyl alcohol can be found in alcoholic beverages. Isopropyl alcohol is alcohol that is used topically to kill germs and is a common ingredient in soaps, shampoos and cleaners, among other things. Isopropyl alcohol will cause illness or even death if it is ingested. Ethyl alcohol, on the other hand, is mainly used for drinking. Ethyl alcohol is usually sold in a diluted form for safety when drinking and although illness can occur, it's not likely unless great amounts are consumed.
Ethyl Alcohol Manufacturing
Ethyl alcohol is manufactured by reacting ethane with steam. Ethane is derived from a natural source, most commonly corn in the United States. From this, only 5 percent of the ethene is converted into ethanol gas on each pass through the steam process, so it is run through many times to achieve a 95 percent conversion of ethene to ethanol. Ethanol gasses are then cooled to form liquid ethyl alcohol. It can then be sold as pure "grain alcohol" for drinking, mixed with other edible ingredients or denatured to make it unfit for drinking to be used in industrial applications.
Isopropyl Alcohol Manufacturing
Isopropyl alcohol is made from fossil fuels that are processed through a hydration process where the propene derived from the fossil fuel is combined with water causing a chemical reaction. Distillation then occurs to process out any byproducts to form pure isopropyl alcohol. This can then be mixed back with a percent of distilled water or sold in pure form. It can also be used as ingredient in healthcare or cleaning products at this point.
Both ethyl and isopropyl alcohol are sold as antiseptics and are flammable. Otherwise, the forms vary greatly. Ethyl alcohol is considered "pure" alcohol, even when it is mixed with water and other ingredients. Ethyl alcohol can be purchased in a pure form, called grain alcohol. It is denatured and sold as a paint stripper, harsh cleanser or in other industrial non-edible forms. Isopropyl alcohol is sold in a diluted mixture of 72 percent to be less harsh as a topical treatment and at 99 percent for use as antiseptic rubbing alcohol or for use as a flammable agent. There is no edible form of isopropyl alcohol.