Plastic #4 (LDPE) Curbside Trash These type of plastic containers are not recyclable. Help Prevent Litter Plastic #4 is a lightweight material that easily finds its way into the environment, where it can leach toxic chemicals. Dispose of it properly to prevent it from becoming litter. 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.