Intended for very large scale integration (VLSI), this general use grade sulfuric acid is often used in the manufacturing process of phosphoric acid for use in phosphate fertilizers. It is also applied to synthesize ammonium sulfate by creating a reaction with the ammonia produced by decomposing coal with waste sulfuric acid from steel and iron foundries. The resulting product is then sold to agro-chemical manufacturers for use as fertilizer. Great care should always be taken when handling or using sulfuric acid, as it is also hygroscopic and readily absorbs water vapour from the air. This characteristic along with hydrolysis on contact with tissue is why highly concentrated sulfuric acid causes severe secondary thermal burns due to its dehydrating properties. Universal precautions should be mandatory for worker safety, and any individual working with any quantity of sulfuric acid should read the material safety data sheet carefully prior to handling or use.