In this article written by Laurinda Morris DVM for BigCatRescue she states; "There shouldn’t be – but there is - a gray area to a solid understanding and definition of human grade ingredients. The gray area happens for two reasons. One – AAFCO has no official definition of human grade ingredients. So a manufacturer can say human grade and not be held accountable for such claims. Second, it happens because pet food manufacturers that purchase by-products (feet, heads, intestines, and so on) purchase these ingredients from a USDA approved meat processing facility. They are using (or misusing) the term human grade/quality to mean the products come from a USDA approved meat processing facility. The reality that by-products are human grade/quality is far from the truth." http://www.bigcatrescue.org/pets/PetGradeHumanGrade.htm
ETA: I also found it odd that this particular company lists no address on their website, only a P.O. Box.