What about Styrofoam that is stamped 6?

No.Polystyrene Styrofoam is a number 7 plastic. Many Styrofoam containers are stamped as recyclable, but our Materials Recovery Facility can only process plastics numbered 1 - 6.Styrofoam, including takeaway containers, meat trays and packaging should be placed in your general waste bin or reused around the home.