Why do you say that?
There are some nasty & very unhealthy chemicals in commercially produced bacon. We lost a beloved Rottweiler years ago at age 7. She got sick and died seemingly out of the blue. When the local veterinary college did an autopsy they called and asked if we ever gave the dog bacon grease. Which we did. They told us that the cause of death was pancreatitis from the chemicals in commercially produced bacon.
Turned out my uncle was also having issues with his pancreas, so we told him the above info and he told his Doctor. He stopped eating commercially produced bacon and using the grease from commercially produced bacon and very quickly got better. This is why we make our own now. No dangerous chemical cocktails or nitrates included.