So easy to overlook, the recycling triangle has become a ubiquitous part of life that we glance over however many times a day, but do we ever stop and ask ourselves what those little numbers inside the triangle mean?
Recycling
As a plastics industry journalist ever keen to learn and share knowledge, I have de-coded the recycling triangles and reveal what numbers one-to-seven mean to we, the consumer.
1 - PET
These are usually found on your common or garden mineral water bottles and are among the most commonly used plastics in packaging and consumer goods. PET is found in a lot of
David.Monniaux via Wikimedia Commons
Bottle
disposable products as the material is difficult to decontaminate, however, it is very recyclable with around a quarter of PET bottles getting a second life as recycled material - often in textiles such as carpeting material.
It is recommended that products made of this labelled PET plastic should be recycled but not reused - at least for prolonged periods of time - because its semi-porous characteristics mean it absorbs the molecules of the food or beverage it contains, however heating can sterilise the plastic to a great extent.
2 - HDPE
HDPE is most commonly used in detergent bottles, milk jugs and other disposables including plastic carrier bags, but it can be found in reusables that come under daily stress and impact
HDPE
such as rubbish bins, toys and my own sports bottle - the one I have on my desk every day while I write EPPM. HDPE is one of the most recycled plastic materials and is cost-effective to process for reuse. It is hard-wearing and resistant to temperature, weather and repeated use and handling.
Products made of HDPE are meant to be reused and recycled with food-grade recycled HDPE being reprocessed into packaging materials, while it can also be processes as a recycled material for 3D printing.
3 - PVC
PVC is one of the best-known types of plastic. It is flexible, durable, colourable or clear and has uses in children's products, food packaging and wrap, pipes and cables, windows, garden products and clothing items. PVC has had a bad press because its plasticisers leach phthalates over the lifespan of a product, which have been rules as toxic or carcinogenic, leading to some phthalates being banned by authorities including the European Commission for products such as children's school supplies and toys. Lead has also been historically added to PVC to improve its stability but in Europe lead stabilisation is being phased out.
PVC
PVC cannot be recycled but it can be repurposed - but not for applications where there is a risk of the material being ingested, such as infants' comforters or food packaging.
4 - LDPE
LDPE
LDPE is the friend of the squeezy bottle, the six-pack ring, shrink wrap and bread wrappers. It is a thermoplastic that has excellent chemical resistance and is widely considered to be safe and less toxic. Unfortunately, it is not widely recycled but when it is, its recycled reincarnations tend to be bin liners and floor tiles.
5 - PP
Hard-wearing, lightweight, resistant to heat and moisture, and flexible; PP might be the first plastic product you touch in the morning when you open your cereal box, as it is what the interior bag is made out of. It is often used for plastic food tubs, buckets, rope and string, storage boxes, battery cases and in thermal and sportswear textile fibres.
It is not universally recycled but the tide is turning and many processors are producing high grade compounds for a wide range of applications including thermoforming and injection moulding applications.
Conrflakes
6 - PS
PS or polystyrene is another well-known plastic material. From the beans in your delivery box to the burger van, PS is often used to make disposable food containers, but it is also widely used in
Polystyrene
rigid foam insulation, laminate flooring and other construction applications. It is very lightweight and much less durable than its cousins PP and PVC, but it does suffer the same rap as PVC for being a leacher, as styrene is considered toxic and possibly carcinogenic, with numerous official studies debating exactly how dangerous the chemical is to humans up to this day.
Polystyrene is expensive to recycle because generally it cannot be reprocessed locally, requiring transportation to a specialist plant. Its re-uses as recycled EPS (expanded polystyrene) include non-food packaging, seed trays and hardwood replacement products such as the material you see in modern park benches.
7 - OTHER
'Other' is quite a broad term for what remains, which broadly includes polycarbonate and other materials. These compounds are not standardised for recycling because of the risk of chemical
leaching of BPA, a xenestrogen that has been widely written off as dangerous in recent years for its carcinogenic properties, however these concerns have since been addressed by the European Food Safety Authority, which concluded that BPA "poses no health risk to consumers". Nevertheless, BPA is still the 'baddie' of plastics and you will be hard-pressed to find a baby bottle in Europe containing the chemical unless it is a hand-me-down from several years ago.
These plastics are not generally for re-use but those labelled PLA can be composted, however the long-term consequences of allowing these plastics to 'degrade' is still being debated by experts.
Polycarbonate BayerMaterialScience
One of Bayer MaterialScience’s most important products: the polycarbonate Makrolon.
Sources -
http://www.bpf.co.uk/recycling/Default.aspx
http://www.eps.co.uk/sustainability/recycling.html
http://www.axionpolymers.com/
http://www.epa.gov/airtoxics/hlthef/styrene.html
http://learn.eartheasy.com/2012/05/plastics-by-the-numbers/
http://naturalsociety.com/recycling-symbols-numbers-plastic-bottles-meaning/
http://www.efsa.europa.eu/
http://envisionplastics.com/
