Recycling codes are not consistently applied, a bottle might have lost its label, many plastics use mixed types and lots of food and drink containers are pollut

Recycling codes are not consistently applied, a bottle might have lost its label, many plastics use mixed types and lots of food and drink containers are polluted by the food and liquids so they are still dirty. You can tell people to wash things and separate them but you can't really police it and when it doesn't happen, you have to inspect everything to ensure that nothing gets through!