Meat, poultry, and fish material that is not fit for human consumption is sent to renderers that process these materials into fats, oils, and protein for feed in the animal, poultry, and pet food industries, as well as ingredients in soaps, paints and varnishes, cosmetics, explosives, toothpaste, pharmaceuticals, leather, textiles, and lubricants. The muscle, fat, bones and other animal tissues are changed into a protein rich substance which looks like sand or soil a much safer, more easily stored and less objectionable form. Unlike raw waste materials, the products derived from rendering can be stored for long periods of time. The temperature and length of the rendering process kills or inactivates traditional disease causing organisms and for years were viewed as a stage at which the disease transmission cycle could be disrupted. In the past, protein and fat products were seen as sterile, although subject to new contamination if not properly stored or handled. Rendering has produced valuable and marketable protein and fat products from meat production waste, including dead stock.