Ammonia, or azane, is a compound of nitrogen and hydrogen with the formula NH3. It is a colourless gas with a characteristic pungent smell. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or indirectly, is also a building-block for the synthesis of many pharmaceuticals and is used in many commercial cleaning products. Although in wide use, ammonia is both caustic and hazardous. The global industrial production of ammonia for 2012 was anticipated to be 198 million tonnes, a 35% increase over the estimated 2006 global output of 146.5 million tonnes.