Methyl alcohol and methanol are the exact same chemical substance, representing two names for the same simple compound. This substance is the smallest molecule in the alcohol family, containing only one carbon atom. It is a colorless, volatile, and flammable liquid with widespread industrial applications.
Methyl Alcohol and Methanol: A Single Compound
The difference between the two terms comes down to chemical naming conventions. “Methanol” is the internationally recognized and preferred systematic name established by the International Union of Pure and Applied Chemistry (IUPAC). “Methyl alcohol,” along with “wood alcohol” or “wood spirit,” is a traditional common name. The chemical structure is defined by the formula CH3OH. This molecule consists of a single carbon atom bonded to three hydrogen atoms (the methyl group) and a hydroxyl (-OH) group, classifying it as the simplest aliphatic alcohol.
Practical Uses and Everyday Exposure
Methanol is used to create a vast array of products. Approximately 70% of the methanol produced is used as a chemical building block for other materials, most notably formaldehyde, which is used in plastics and adhesives. It is a highly effective solvent, appearing in commercial products like paints, varnishes, and paint thinners. Consumers commonly encounter it as an antifreeze agent in windshield washer fluid, where it prevents freezing. Trace amounts of methanol are also naturally present in many common foods, including fresh fruits, vegetables, and fermented beverages, but these small dietary exposures are harmless.
The Danger Profile: Why Methanol is Poisonous
The danger of methanol lies in the toxic byproducts created when the body attempts to process it. Upon ingestion, the liver enzyme alcohol dehydrogenase (ADH) begins to metabolize methanol into formaldehyde. Formaldehyde is then rapidly converted to formic acid, or formate, by another enzyme. This accumulation of formic acid leads to severe metabolic acidosis and cellular damage.
Formic acid is destructive to the optic nerve and retina, causing permanent vision loss or complete blindness, even from a small dose. Ingesting as little as 10 milliliters of pure methanol can result in irreversible eye damage, and 30 milliliters may be a lethal dose. This is different from drinking alcohol (ethanol), which is metabolized into much less toxic compounds that the body can clear more easily.