Mammalian excreta, rodent filth, insect filth, mould, rot, insects, larvae, mites, insect eggs, sand and grit, mildew, parasites: an unappetising list, but the US Food and Drug Administration publishes a useful handbook detailing the acceptable amounts of such contaminants in a range of foods.
US consumers are told to expect to find up to 60 aphids / thrips / mites in every 100g of frozen broccoli (but only up to 30 in frozen Brussels sprouts), up to 60 insect fragments in a 100g chocolate bar, up to 4 rodent hairs in 25g of curry powder, and a “copepod accompanied by pus pockets” in 3% of their red fish fillets. These are the specified action levels, below which there is “no inherent hazard to health”.
