Manufacturing equipment

How do you view the potential issue of equipment in a factory being used for non kosher products or being greased with non kosher products like animal fats? Why doesn’t that cause an issue of bliot with a “kosher” product that doesn’t contain these items?

Equipment is cleaned.

If there was animal fat in the food it would be on the label.

If the equipment is clean but it’s a בן יומו why isn’t there a concern of בליעות as there almost always never שישים against the entire keli

סתם כליהם של עובדי כוכבים אינם בני יומן

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