I’m still not sure of the difference between insanitary and unsanitary, like insane and unsane, but the dictionary says insanitary means, “so dirty or ridden with germs as to be a danger to health,” whereas 
sanitary is defined as, “of or relating to the conditions that affect hygiene and health,” and the word unsanitary does not exist.
Perhaps a linguist can settle this. In the meantime …
The U.S. Food and Drug Administration today announced intentions to ask a federal court to shut down a New Jersey cheese manufacturer with an alleged history of operating under insanitary conditions and producing cheese contaminated with Listeria monocytogenes.
The U.S. Department of Justice filed a complaint for permanent injunction against Quesos Mi Pueblito and two of its officers, Felix Sanchez and Jesus Galvez. The complaint alleges that recent inspections by the FDA and the New Jersey Department of Health and Senior Services found Listeria-contaminated cheese and insanitary conditions at the Passaic company.
If entered by the court, the injunction would stop the company and its officers from manufacturing and distributing food until they can bring their operations into full compliance with FDA food safety regulations and produce cheese that does not test positive for the presence of Listeria. The complaint for permanent injunction was filed in the U.S. District Court – District of New Jersey.