formaldehyds

Formaldehyds, more commonly referred to as formaldehyde (IUPAC name methanal), is the simplest aldehyde with the chemical formula CH2O. It is a colorless gas at room temperature with a sharp, distinctive odor. In water it forms formalin, a stable solution typically around 37% formaldehyde by weight. Formaldehyde also exists as oligomeric forms such as paraformaldehyde under certain conditions.

Industrial production centers on the catalytic oxidation of methanol. Formaldehyde is also produced endogenously in living organisms and occurs in trace amounts in some foods and plants. It serves as a versatile precursor in many chemical syntheses and is used extensively in consumer products and manufacturing.

Applications include the production of resins such as urea-formaldehyde, phenol-formaldehyde, and melamine-formaldehyde, which are used as adhesives in particleboard, plywood, and other wood products. It is also used as a disinfectant, preservative, and sterilant, and as a fixative in histology and, historically, in embalming. It appears in some textiles, paper products, cosmetics, and cleaning agents.

Chemically, formaldehyde readily reacts with nucleophiles, especially amino and thiol groups, forming a range of adducts. In water it equilibrates with methanediol (hydrated formaldehyde). It polymerizes to paraformaldehyde upon evaporation or heating. It is highly soluble in water and miscible with many organic solvents.

Health and safety: formaldehyde is an irritant to the eyes, skin, and respiratory tract. Prolonged or high-level exposure is associated with cancer risk; the International Agency for Research on Cancer classifies it as a human carcinogen. Regulatory exposure limits vary by jurisdiction, but work environments emphasize ventilation, containment, and protective equipment. Environmental releases are regulated, and formaldehyde degrades in the atmosphere through oxidation.