Formaldehyde (/f??r'mæld?ha?d/ ? for-MAL-di-hide US also /f?r-/ ? f?r-) (systematic name methanal) is an organic compound with the chemical formula CH2O and structure H-CHO 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 (R-CHO). 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. It is mainly used in the production of industrial resins e.g. for particle board and coatings. Small amounts also occur naturally.