I always thought years back that uneatable items when slaughtering animals was thrown away, such as bones and organs. Until I worked (briefly) in a tannery.

I got a fast education in how ‘the industry’ works. After dumping highly toxic levels of chemicals on the skins to make them into leather there was still half dissolved flesh still on the skins. Hunters when skinning a deer for example in the woods, will make the cuts into the skin but it is difficult to skin the legs. So they are broken and left on the skin. Same with the genitals and pieces of flesh that stayed with the skin when it was ripped off. One of my jobs was cutting off these extra pieces of flesh and legs and putting them into a 55gal drum. Them the skin was put through a large grinder that ripped off the grey(from the chemicals) flesh and left the skin ready to go into the washing machines. All that grey flesh and chemicals was then shoveled up (sometimes it was knee deep) and put into the 55 gal drums. Then a rendering company picked it up and was used in products such as gelatin, makeup, animal food. Supposedly it was “cleaned” of the toxic chemicals. So think of that the next time you put on your lipstick. ewww.