Upton Sinclair's investigation into meatpacking plants revealed horrifying working conditions. For example, some men "worked in tank rooms full of steam," where "there were open vats near the level of the floor." In such rooms workers often "fell into the vats; and when they were fished out, there was never enough of them left to be worth exhibiting, — sometimes they would be overlooked for days, till all but the bones of them had gone out to the world as Durham's Pure Leaf Lard!"

Other workers told Sinclair stories of appalling sanitary practices:

With one member trimming beef in a cannery, and another working in a sausage factory, the family had a first-hand knowledge of the great majority of Packingtown swindles. For it was the custom, as they found, whenever meat was so spoiled that it could not be used for anything...