What does acetaldehyde mean?
Acetaldehyde is a colorless, highly volatile, and flammable organic compound with the chemical formula CH3CHO and a sharp, sometimes fruity odor. Chemically, it belongs to the aldehyde family and ranks among the simplest members of that class; its systematic name is ethanal. Industrially it serves mainly as an intermediate in producing acetic acid, plastics, perfumes, and flavorings, though much of modern production now favors alternative routes. Acetaldehyde also occurs naturally: fruit ripening generates small amounts, and the human body produces it whenever alcohol is consumed, as the liver first converts ethanol into this compound before rendering it harmless. That intermediate step matters medically, because accumulated acetaldehyde is responsible for many unpleasant effects of drinking, including flushing and hangover symptoms, and chronic exposure is classified as carcinogenic. Consequently the word appears mostly in chemistry, toxicology, food science, and public-health discussions rather than casual conversation.
nounAcetaldehyde is a volatile, flammable organic compound (CH3CHO) — a colorless liquid with a pungent, fruity odor, formed by the partial oxidation of ethanol and used chiefly as an intermediate in the manufacture of acetic acid, plastics, and other chemicals. It is also produced naturally in the human body as a byproduct of alcohol metabolism.
- A colorless, volatile, flammable liquid aldehyde (CH3CHO) with a pungent fruity odor, produced industrially and formed in the body during the metabolism of alcohol.
"The liver converts most of the alcohol in the bloodstream into acetaldehyde before breaking it down further."
"Exposure to high concentrations of acetaldehyde can irritate the eyes, skin, and respiratory tract."
"In people with a certain genetic variant common in East Asian populations, acetaldehyde accumulates after drinking, causing flushing and discomfort."
As an uncountable chemical substance, acetaldehyde normally takes no plural; the rare plural form refers to distinct types, samples, or derivatives of the compound.
"Trace acetaldehydes were detected in several of the aged wine samples."
That pounding morning-after hangover headache? You can largely blame acetaldehyde — a toxic compound your body produces as it breaks down every drink you take.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of acetaldehyde
The word acetaldehyde was coined in the 19th century from a contraction of 'acetic aldehyde,' reflecting its discovery as the oxidation product lying between ethyl alcohol and acetic acid. The element 'acet-' traces back through Latin acetum ('vinegar') to the Indo-European root for sourness, while 'aldehyde' derives from the Latin phrase de alcoholatus, abbreviated from 'dehydrogenated alcohol,' describing how such compounds are formed by removing hydrogen from an alcohol. Related terms sharing the acet- root include acetic, acetate, and acetone.
How acetaldehyde is actually used
Strictly technical register: acetaldehyde appears almost exclusively in chemistry, medicine, toxicology, and food-science contexts rather than everyday speech. In chemistry it is also known by its systematic IUPAC name 'ethanal.' It is classified by IARC as a Group 1 carcinogen, which is worth noting when writing for health or safety audiences.
Easily confused with acetaldehyde
Formaldehyde is the simplest aldehyde (HCHO), used in embalming and resins, whereas acetaldehyde is a related but distinct two-carbon compound formed during alcohol metabolism.
Acetone is a ketone (a solvent found in nail polish remover), while acetaldehyde is an aldehyde produced by oxidizing ethanol.