Formaldehyde is a naturally-occurring organic compound with the formula CH2O or HCHO. It is the simplest aldehyde and is also known by its systematic name methanal. The common name of this substance comes from its similarity and relation to formic acid. A gas at room temperature, formaldehyde is colorless and has a characteristic pungent, irritating odor. It is an important precursor to many other materials and chemical compounds. In 1996, the installed capacity for the production of formaldehyde was estimated to be 8.7 million tonnes per year. Commercial solutions of formaldehyde in water, commonly called formol or formalin , were formerly used as disinfectants and for preservation of biological specimens. It is also used for the embalming of human remains. It is commonly used in nail hardeners and/or nail varnish. In view of its widespread use, toxicity and volatility, exposure to formaldehyde is a significant consideration for human health. In 2011, the US National Toxicology Program described formaldehyde as “known to be a human carcinogen”.