Here's the definition that's on our security deposit page, which doesn't get into the nitty-gritty: Normal wear and tear is a term that Wisconsin law does not define.
(3)Protein Fat-Free Percentage, Protein Fat-Free Content, PFF Percentage, PFF Content or PFF of a product means the meat protein (indigenous to the raw, unprocessed pork cut) content expressed as a percent of the non-fat portion of the finished product.
U.S. federal law divides the food processing sector into two broad categories: meat/poultry as overseen by the Food Safety Inspection Service (FSIS) of USDA and all other food processors as overseen by the FDA.