Rendering is a process that converts waste animal tissue into stable, usable materials. Rendering can refer to any processing of animal products into more useful materials, or, more narrowly, to the rendering of whole animal fatty tissue into purified fats like lard or tallow. Rendering can be carried out on an industrial, farm, or kitchen scale. It can also be applied to non-animal products that are rendered down to pulp. In animal products, the majority of tissue processed comes from slaughterhouses, while the most common animal sources are beef, pork, mutton, and poultry. The rendering process simultaneously dries the material and separates the fat from the bone and protein, yielding a fat commodity and a protein meal. The occupation of renderer has been described as dangerous and dirty.