Isopropanol and isopropyl alcohol are two different names for what is the same chemical compound.
In fact, the various chemistry naming standards and conventions means this widely used substance actually has several names. Continue reading to learn more about isopropanol and why a single compound can often have multiple names.
In this post:
Isopropanol vs isopropyl alcohol: Is there a difference?
Isopropanol is a colourless and flammable liquid with the chemical formula (CH3)2CHOH. Available in various grades, it has a wide range of applications across many industries. For example, rubbing alcohol, which contains between 70% and 90% isopropanol or ethanol, is often used as an antiseptic and surface disinfectant.
Isopropanol is also called isopropyl alcohol, which can understandably cause confusion among the general public. However, it’s important to remember that this is simply a different name for the same chemical compound. In other words, there’s no difference between isopropanol and isopropyl alcohol.
Some of the other names by which isopropanol is known include the following:
- Rubbing alcohol
- sec-Propyl alcohol
- Dimethyl carbinol
As we explain below, a substance may have more than one name because there are several standards for naming chemical compounds.
Why are different names used?
In chemistry, there are different standards or conventions (called chemical nomenclature) for naming compounds like alcohol. The most common chemical nomenclature is from the International Union of Pure and Applied Chemistry (IUPAC) – a scientific body set up in 1919 to standardise nomenclature and chemical terminology (among other things).
There’s also the common naming system for simpler chemical compounds. For example, we say “water” instead of H2O or dihydrogen monoxide. In the case of isopropanol, a combination of the two different standards for chemical nomenclature have been used over time. As a result, we’ve ended up with several names for the same chemical.
IUPAC nomenclature provides functional class names and substitutive names. The IUPAC functional class name is isopropyl alcohol, and the substitutive name is isopropanol. However, these are both ‘general’ names, since the ‘iso’ prefix is from the common naming system. Under the IUPAC system, the correct name is propan-2-ol, although this isn’t as widely used as isopropanol or isopropyl alcohol.
The standard IUPAC name propan-2-ol indicates both the type of hydrocarbon chain attached to the hydroxyl group and the point of attachment.
Standardised and precise names of chemical compounds like alcohol are crucial in helping to identify different substances. A standardised nomenclature like the IUPAC convention is also descriptive and provides information about the substance’s structure and composition.
Safety and handling of isopropyl alcohol
Isopropyl alcohol is commercially available as rubbing alcohol and gels in 70% concentration. Its ability to kill bacteria makes it an effective hand sanitiser and disinfectant. Isopropyl alcohol is toxic to humans and, if ingested, can lead to ketosis without acidosis. Although rarely fatal in adults, it can be life-threatening for infants/children and pets.
Isopropyl alcohol must therefore be handled and stored correctly. Like other alcohols, it poses a fire hazard because it can be easily ignited. The chemical must be stored in its original container and out of reach of children. You should also dilute any residual isopropyl alcohol with water before pouring the contents down the drain.
We sell high-quality isopropyl alcohol in different grades and pack sizes in our online shop.
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