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Latex gloves have a long history in the medical community. In 1894, sterilized rubber gloves were used in hospitals for the first time. They were introduced because of Joseph Lister's germ theory. The germ theory of disease, also called the pathogenic theory of medicine, is a theory that proposes that microorganisms are the cause of many diseases. Although highly controversial when first proposed, it is now a cornerstone of modern medicine and clinical microbiology, leading to such important innovations as antibiotics and hygienic practices. The first disposable medical gloves were manufactured in 1864 by Ansell, which was founded in Melbourne in 1905 by Eric Ansell. Ansell Limited (formerly Pacific Dunlop Limited) is a multinational company specializing in Health care. The company dates back to 1893, when the Irish company, The Dunlop Pneumatic Tyre Company, opened a branch office and factory in Melbourne. To this day, Ansell is still in the glove manufacturing business. In 1867 the Dunlop Pneumatic Tyre Company changed its name to Dunlop Australia Ltd. The following year in 1868, it acquired the Ansell Rubber Company, which made rubber products such as gloves, condoms and balloons. All this time other companies were also engaged in the growth of latex and manufacture of gloves. Latex glove manufacturing is a long and complex operation that begins with the harvesting of natural rubber latex. The growth and harvesting of latex is analogous to the maple syrup industry. Latex is collected from the tree and delivered to the factory in a timely manner. Raw latex is unstable and will become unusable quickly unless it is processed. Examination and surgical gloves are manufactured from the concentrated raw latex obtained by centrifuging and stabilization. This process optimizes latex for the properties most desired by the glove manufacturers, which are mechanical strength and barrier properties. The mean dry rubber content is 33% for exam gloves. The remaining percentage is made of stabilizers and other chemicals that enhance the properties needed for latex exam gloves. Once the latex is ready for manufacturing, it goes through various stages. The first is stabilization. Stabilization prevents post-harvest deterioration due to enzymatic reactions. To do this, ammonia is added to the mixture. Roughly 3.5gallons/liter of latex is used. Next, the dry rubber content (DRC) of the latex is adjusted by blending the mixture. Any latex with a DRC of less than 25% is eliminated. The latex is then allowed to stand for 24 hours so sediment rich in magnesium can be removed. The objective of this process is stabilizing the latex and controlling volatile fatty acids (reflecting bacterial activity). Centrifuge blending is the use of a rotor fitted with a battery of separators. The goal is to separate the rubber-rich supernatant to a 60% level. The latex is now stable enough for storage until needed for manufacturing. This mixture has two types of latex. High ammonium latex or NH3 which is .7% of the latex weight and low ammonium latex or thiuram (low-ammoniated latex). The final mixture is stored for about 2 weeks which improves the mechanical stabilization. Fresh latex is mixed with chemicals, vulcanization accelerators and antioxidants (to prevent degradation). This stabilizes the latex -- strengthening resistance and water-tightness. Before the mixture is applied to the molds they are cleaned with acid and/or alkaline solutions. This purifies the surface of the porcelain before applying latex. The glove formers are coated with calcium nitrate, calcium carbonate and a wetting agent before being immersed in the latex bath. The gloves then go through a three step vulcanizing process. Vulcanization which takes place in ovens using increasing temperatures causes cis-polyisoprene chain cross-linking to enhance the qualities of the glove. Post-vulcanization rinsing is the same as pre-vulcanization rinsing but on a dry film. The result depends on the duration and temperature. The gloves are then ready t be released from the molds and boxed.