At the last job I was fired from
We treated our (infested) facility with dichlorovous (aka Vapona) - I had to get a special license to supervise our employees, and we got to do blood tests, and wear masks and release the building.
Well, if you have organic in your facility, which we did, you have to move it out, because dichlorovous isn't allowed for organic food (and frankly I'm amazed it hasn't been banned for people food, despite petitions almost annually)
So we would move the organic out to our trailers outside. The lines took like 16 hours to clean, and that was all done -pre shut down.
Because we would be bringing organic product in first, it was easiest for clean out schedules etc to bring it back and run it (no pre-organic clean out, because the lines had been cleaned the weekend before fogging)
But we never cleaned the surfaces of the equipment after fogging. Just ran. And started with organic! And the place was so gross after we fogged- you could feel the film on desks, chairs, everything.
We had General Mills as a customer and they tested our product and when, came up with dichlorvous. It's half life is very short, so we waited a week and sent them another sample from the same lot, which was magically negative.
I wanted a pretty simple corrective action as the Sanitation Supervisor / Pest Control "Guy" - wash the lines before running. The QA Manager & Plant Manager looked at the clean time and flat out said no, then got very, very angry at me for suggesting we test it, and refused to acknowledge that they were actively contaminating their IP foods with pesticide.
So I brought it up during our next audit.
Then I got fired a couple days later (mostly for other things, but probably also for this). In the mean time, they're gotten NOP certification as well, and maintain their organic cert, so .. either they went ahead and fixed or they're still doing it. Either way, I don't use them as an ingredient vendor, and I never ate the stuff from there when I worked there.