A lot of this kind of thing happens. There’s limits on bunch of food contaminants that are higher than zero because zero is unrealistic (for example on the amount of rat feces in grain). Generally, the ones closest to the limits will be the ones chosen to be processed further into something where them being second-rate is less obvious. The pretty produce gets sold raw, somewhat uglier produce goes into shredded or finely chopped goods where you can’t see the difference. The flour that’s closer to the limit for rat shit content get processed into factory baked goods where it won’t be as noticeable, etc.