Plastic #4 (LDPE) Recycle Curbside Recycle plastic tubs. Tubs that held products like yogurt, margarine and salsa can be recycled. They must be empty and lightly rinsed. Place lids back on containers before recycling. Did You Know? What Plastic #4 Can Become Plastic #4 can be recycled into shipping envelopes, paneling, tiles, plastic lumber, trash can liners and trash cans.