Soylent has had multiple, well publicized problems with mold and at least one instance of journalists finding rats running around the factory floor.
https://www.google.com/search?q=soylent+moldy
There was one journalist that found rats in the kitchen, during the beta phase of soylent. Presumably when they hit production they used standard manufacturing techniques.
The mold is unfortunate, but only with Soylent 2.0, the pre-made bottles. As soon as they found out they issued a recall, like any responsible company.
https://www.google.com/search?q=soylent+rats