That report caught my attention as I found out that most plastic water bottles in the market are printed with recycling symbol no.7 on it. Even the water bottles i used all these while also have such symbol.
Therefore, I started to feel curious what are these recycling symbols usually printed at the bottom of a plastic container actually mean. I did some reading on the Internet and trusted source and here is my finding to share with all of you.
Plastic Polymer: Polyethylene Terephthalate (PET or PETE)
Packaging Application: Soft drink, water and beer bottles; mouthwash bottles; peanut butter containers; salad dressing and vegetable oil containers; ovenable food trays.
Recycling: Picked up through most curbside recycling programs.
Recycled into: Polar fleece, fiber, tote bags, furniture, carpet, paneling, straps, (occasionally) new containers
Properties: Clarity, strength, toughness, barrier to gas and moisture.
Additional Info: PET plastic is the most common for single-use bottled beverages, because it is inexpensive, lightweight and easy to recycle. It poses low risk of leaching breakdown products.
Plastic Polymer: High Fensity Polyethylene (HDPE)
Packaging Application: Milk jugs, juice bottles; bleach, detergent and household cleaner bottles; shampoo bottles; some trash and shopping bags; motor oil bottles; butter and yogurt tubs; cereal box liners.
Recycling: Picked up through most curbside recycling programs, although some allow only those containers with necks.
Recycled into: Laundry detergent bottles, oil bottles, pens, recycling containers, floor tile, drainage pipe, lumber, benches, doghouses, picnic tables, fencing.
Properties: Stiffness, strength, toughness, resistance to moisture, permeability to gas.
Additional Info: HDPE is a versatile plastic with many uses, especially for packaging. It carries low risk of leaching and is readily recyclable into many goods.
Plastic Polymer: Polyvinyl Chloride (PVC)
Packaging Application: Window cleaner and detergent bottles, shampoo bottles, cooking oil bottles, clear food packaging, wire jacketing, medical equipment, siding, windows, piping.
Recycling: Rarely recycled; accepted by some plastic lumber makers.
Recycled into: Decks, paneling, mudflaps, roadway gutters, flooring, cables, speed bumps, mats.
Properties: Versatility, clarity, ease of blending, strength, toughness.
Additional Info: PVC is tough and weathers well, so it is commonly used for piping, siding and similar applications. PVC contains chlorine, so its manufacture can release highly dangerous dioxins. If you must cook with PVC, don't let the plastic touch food. Also never burn PVC, because it releases toxins.
Plastic Polymer: Low Density Polyethylene (LDPE)
Packaging Application: Squeezable bottles; bread, frozen food, dry cleaning and shopping bags; tote bags; clothing; furniture; carpet.
Recycling: LDPE is not often recycled through curbside programs, but some communities will accept it. Plastic shopping bags can be returned to many stores for recycling.
Recycled into: Trash can liners and cans, compost bins, shipping envelopes, paneling, lumber, landscaping ties, floor tile.
Properties: Ease of processing, strength, toughness, flexibility, ease of sealing, barrier to moisture.
Additional Info: LDPE is a flexible plastic with many applications. Historically it has not been accepted through most American curbside recycling programs, but more and more communities are starting to accept it.
Plastic Polymer: Polypropylene (PP)
Packaging Application: Some yogurt containers, syrup bottles, ketchup bottles, caps, straws, medicine bottles.
Recycling: Number 5 plastics can be recycled through some curbside programs.
Recycled into: Signal lights, battery cables, brooms, brushes, auto battery cases, ice scrapers, landscape borders, bicycle racks, rakes, bins, pallets, trays.
Properties: Strength, toughness, resistance to heat, chemicals, grease and oil, versatile, barrier to moisture.
Additional Info: Polypropylene has a high melting point, and so is often chosen for containers that must accept hot liquid. It is gradually becoming more accepted by recyclers.
Plastic Polymer: Polystyrene (PS)
Packaging Application: Disposable plates and cups, meat trays, egg cartons, carry-out containers, aspirin bottles, compact disc cases.
Recycling: Number 6 plastics can be recycled through some curbside programs.
Recycled into: Insulation, light switch plates, egg cartons, vents, rulers, foam packing, carry-out containers
Properties: Versatility, clarity, easily formed
Additional Info: Polystyrene can be made into rigid or foam products -- in the latter case it is popularly known as the trademark Styrofoam. Evidence suggests polystyrene can leach potential toxins into foods. The material was long on environmentalists' hit lists for dispersing widely across the landscape, and for being notoriously difficult to recycle.
Plastic Polymer: Miscellaneous/Other (often Polycarbonate or AMS)
Packaging Application: Three- and five-gallon water bottles, 'bullet-proof' materials, sunglasses, DVDs, iPod and computer cases, signs and displays, certain food containers, nylon.
Recycling: Number 7 plastics have traditionally not been recycled, though some curbside programs now take them.
Recycled into: Plastic lumber, custom-made products.
Properties: Dependent on polymers or combination or polymers.
Additional Info: A wide variety of plastic resins that don't fit into the previous categories are lumped into number 7. A few are even made from plants (polyactide) and are compostable. Polycarbonate is number 7, and is the hard plastic that has parents worried these days, after studies have shown it can leach potential hormone disruptors.
Reference from Wikipedia and thedailygreen.