They dont let it pass to an extent because there are tolerances. If you want 100% in a manufacturing environment the end consumer would be paying double or triple the cost. A loaf of bread would be damn near $15.I couldn’t figure out why the conveyor belt wasn’t covered with plexiglass? I did do some work for place that made cookies for a big grocery store brand. Rats had eat holes in the bags of flour and chocolate. I can’t believe so called health inspectors let this kind of stuff pass??
I did a shutdown at the Kellogg plant on fulton industrial years back where they make waffles. It was surprisingly not that bad, but still gross and that smell is forever ingrained in my head.