What does formaldehyde mean?
Formaldehyde is a colourless gas with a sharp, irritating odour, chemically known as CH₂O or methanal. It rarely appears in pure gaseous form in daily life; instead it is usually handled dissolved in water as a solution called formalin, which has long been used to preserve biological specimens, disinfect surfaces, and embalm bodies. Industrially, formaldehyde is enormously important as a building block for resins, adhesives, and plastics found in plywood, particleboard, and countless household products. Because it is classified as a human carcinogen and can off-gas from furniture and building materials, the word also features prominently in public-health discussions about indoor air quality and product safety. The name derives from formic acid, the compound responsible for ant stings, reflecting how chemists first produced it. Formaldehyde thus sits at an unusual intersection: a cornerstone of modern manufacturing whose very name can evoke laboratories, preservative jars, and chemical caution.
nounA colourless, pungent-smelling gas (CH₂O) that is highly soluble in water, typically handled as an aqueous solution called formalin, used chiefly as a preservative, disinfectant, and in the manufacture of resins and other industrial chemicals.
- The colourless pungent gas CH₂O, used industrially in making resins, plastics, and disinfectants.
- Its aqueous solution (formalin) as used to preserve biological specimens and embalm bodies.
"Specimens in the biology lab were preserved in jars of formaldehyde."
"The new particleboard furniture released small amounts of formaldehyde into the air."
"Frogs dissected in introductory biology classes are stored in formaldehyde before the term begins."
Formaldehyde refers to a specific chemical substance and is almost always treated as uncountable; a plural form exists only rarely, for instance when distinguishing different grades or solutions in technical catalogues, and should generally be avoided in ordinary writing.
"The catalogue listed several commercial formaldehydes of varying concentration."
Formaldehyde literally got its name from formic acid — the same compound ants squirt — because chemists first made it by oxidising that acid.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of formaldehyde
The word formaldehyde was coined in German scientific literature in the latter half of the 19th century, combining 'form(yl)' — referring to formic acid, which itself comes from Latin 'formica', meaning ant, since formic acid was first isolated from ants — with 'aldehyde', a general class name derived from 'alcohol dehydrogenatum'. It entered English usage around the 1870s as organic chemistry vocabulary standardised across Europe. Related words sharing this root include formic acid and formate, all ultimately tracing back to the Latin word for ant.
Related word forms
How formaldehyde is actually used
Formaldehyde is a technical/scientific term, encountered mainly in chemistry, medicine, laboratory work, and discussions of building materials and indoor air quality. It carries a mildly unpleasant connotation due to its sharp odour and association with preservation of dead tissue. In everyday contexts, its solution is more often referred to by the trade-influenced name formalin.
Easily confused with formaldehyde
Formaldehyde is the gas itself, while formalin is the aqueous solution, roughly 37% formaldehyde, in which it is commonly sold and used.