Formaldehyde (/fÉËrËmldɪhaɪd/ for-US also /fÉr-/ fÉr-) (systematic name methanal) is an organic compound with the chemical formula CH2O and structure HCHO, more precisely H2C=O. The compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde. It is stored as aqueous solutions (formalin), which consists mainly of the hydrate CH2(OH)2. It is the simplest of the aldehydes (RCHO). As a precursor to many other materials and chemical compounds, in 2006 the global production of formaldehyde was estimated at 12 million tons per year.[14] It is mainly used in the production of industrial resins, e.g., for particle board and coatings. Small amounts also occur naturally.