By Eri Luxton | Updated Aug 30, 2022

What Is an Alcohol?

In everyday language, “alcohol” often refers to ethanol, the drinkable compound found in beverages. In chemistry, however, an alcohol is any compound that contains a hydroxyl (–OH) group attached to a carbon atom [1]. Understanding this definition clarifies how methanol and isopropyl alcohol differ.

Methanol (CH₃OH)

Structure: A single carbon atom bonded to three hydrogens and one hydroxyl group.

Key properties:

• Commonly used as a laboratory solvent and as a component in denatured alcohol.
• Ingesting even a small amount can lead to blindness or death—NIH Medline reports [2].

Isopropyl Alcohol (C₃H₇OH)

Structure: A central carbon bonded to two methyl groups and one hydroxyl group.

Key properties:

• Widely used as a solvent, disinfectant, and cleaning agent.
• Less toxic than methanol but still hazardous if ingested; it is highly flammable.

Safety Warning

Both methanol and isopropyl alcohol are toxic if swallowed, inhaled, or absorbed through the skin. Always use them in well‑ventilated areas, wear appropriate protective gear, and keep them out of reach of children and pets.