If Dustin Hoffman's character in The Graduate had taken the one word of advice given to him in that iconic movie he probably would have done very well for himself. Plastics. They pervade our daily life in the 21st century more than ever before.
In 1988 the Society of the Plastics Industry created the plastics numbering system that we use today in order to make it easier for recyclers to sort the different types of plastic. The numbers are officially called the resin identification codes and it is a national system with 39 states requiring their use on all plastic containers. We know that many of the product labels we print end up on plastic containers, so I thought it might be useful to provide an explanation of what the numbers mean:
1. PET or PETE - polyethylene terephthalate (referred to thankfully as PET) is the most commonly used plastic material. It is popular for soda bottles, bottled water and many types of food because it is light, clear and durable. It can be recycled easily into carpet, fleece, tote bags and furniture.
2. HDPE - high density polyethylene is a more durable plastic that is used in containers for detergent and household cleaners, also milk jugs, juice, shampoo, cosmetics and some shopping bags. It is typically recycled into motor oil bottles, plastic lumber, pipe, floor tiles, buckets and recycling bins.
3. PVC or V - polyvinyl chloride is an extremely tough plastic that weathers well so it used for piping, siding, window frames, medical equipment and cable insulation. It is rarely recycled but it can be recycled into more piping, decking, floor tiles, traffic cones and garden hoses.
4. LDPE - low density polyethylene has good toughness as well as flexibility which is why it is used predominantly in bags for groceries, bread, dry cleaning and garbage. It is also used in many squeezable bottles. It can be recycled into shipping envelopes, trash can liners, floor tile and plastic lumber.
5. PP - polypropylene is used in some yogurt containers as well as syrup and ketchup bottles, straws, bottle caps and medicine bottles. Polypropylene has a high melting point so it is also used for containers of hot liquids. It can be recycled into signal lights, battery cases, brooms, rakes, ice scrapers and bicycle racks.
6. PS - polystyrene is commonly used for disposable plates and cups, egg cartons, meat trays, CD and DVD cases and packaging peanuts. It can be recycled into thermal insulation, light switch plates, license plate frames, camera casings, and foam packaging.
7. Other - this means that the plastic is not made from any of the six main resins and it could be a combination of resins. Bioplastics such as PLA fall into this category as well as polycarbonate and nylons. Some recycling centers take number 7 containers and they are typically recycled into plastic lumber or custom-made products.
The vast majority of plastic bottles used today are either #1 or #2, and many communities will only accept these kinds of plastics for recycling. It is a shame that there is no national recycling program that would standardize recycling across the country and allow the recycling of all the different types of plastic. But that is a subject for a different day.
Additional Resources
The Daily Green
Plastic Recycling on Wikipedia
The Association of Postconsumer Plastic Recyclers
The American Chemistry Council guide to plastic packaging resins
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