Wondering about the little numbers on your milk container? They identify what the container is made of — and what it will be in its next life.

1 PET (polyethylene terephthalate): Soda bottles; recycled into pillow fill.

2 HDPE (high-density polyethylene): Plastic milk bottles, detergent bottles; recycled into new detergent bottles.

3 PVC (polyvinyl chloride): Take-out boxes, shampoo; recycled into drainage and irrigation pipes.

4 LDPE (low-density polyethylene): Grocery bags, shrink wrap; recycled into new bags.

5 PP (polypropylene): Yogurt containers, bottle caps; recycled into plastic lumber.

6 PS (polystyrene): Packing peanuts; recycled into plastic lumber, cassette-tape boxes.

7 Other: Includes squeezable ketchup bottles and microwavable dishes; these items can’t be recycled.