[WillowTheWhisp]

Use the blue sack for plastic bottles only, i.e. milk, shampoo, pop, washing-up plastic bottles etc and metal cans/tins and foil. Do not put any domestic refuse, nappies, or plastic toys into the sack as these can not be recycled. Take care when presenting your sack for collection to prevent problems of spillage. Wherever possible, wedge the sack between other containers.

Use the blue box for glass jars and bottles only. Rinse debris from cans and glass containers before putting them in the box. Wash out your box occasionally as this will help keep it clean

There's a bit of ambiguity there about the cans.