Identifying everyday plastic products as recyclable
The well known 'chasing arrow' symbol we see on plastic products does not necessarily mean a plastic item can be recycled or even reused. The important part is the number inside the triangle, the resin code. These are stanardised around the world and quickly identify the polymer.
Further information on properties, reusability and reduce
Industry applies the resin identification codes (RICs) to plastics but it is up to us to read and handle them appropriately for both our own good-health and sustainability.
Number 1: PET - Polyethylene terephthalate
This is the most widely recycled plastic. It is also one of the most common plastics. This is intended for single use; repeated usage can have negative effects on health due to the increased risk of leaching and bacterial growth.
- Recycle but don't reuse!
- PET may leach carcinogens.
- PET is commonly recycled into new PET containers, carpet, panelling, polyester fibres and fillings.
- Stable use temperatures: -70°C to 150°C
- PET is non-biodegradable
Number 2: HDPE - High-density polyethylene
This is one of the safest plastics for reuse and it is also highly recyclable.
- Recycle or reuse. Provided that you wash bottles of this plastics, you can reuse them at your own will!
- HDPE is a stiff and hard-wearing plastic.
- HDPE is chemically resistant and does not break down on exposure to sunlight.
- Stable use temperatures: -400°C to 60°C
- HDPE is non-biodegradable
Number 3: PVC - Polyvinyl chloride
This plastic is rarely recycled because most uses of PVC require virgin material. It is possible to recycle at some recycling centres across Europe but it should not be reused. Less than 1% is recycled!
- Non-recyclable and non-reussable! It should be placed in the general waste bin.
- It is difficult to identify without seeing the symbol. Sometimes it is used for meat packaging and cling film.
- Relatively impervious to sunlight and weathering.
- Stable use temperature <60°C
- PVC is non-biodegradable
Number 4: LDPE - Low-density polyethylene
LDPE is considered less toxic than other plastics and suitable for limited reuse. It is not commonly recycled, although more and more centres are accepting this material now. This is the most common commodity plastic in use.
- LDPE is non-recyclable under most programmes but it is important to check with your local recycling programme. LDPE is more likely to be collected for recycling in more urban areas.
- Check the resin code number but the vast majority of thin, flexible, lightweight packaging is made of LDPE if not PET.
- LDPE is relatively impervious to weather and chemicals but some solvents cause swelling. The plastic degrades in solar radiation to release potent greenhouse gases (methane & ethylene).
- Stable use temperature -50°C to 85°C
- LDPE is non-biodegradable
Number 5: PP - Polypropylene
PP is very safe for reuse and is the second most commonly used plastic for commodities.
- PP is recyclable under some programmes but it is important to check with your local authority. It is often used for microwaveable food packaging and containers that must accept hotter liquids or contain oils or solvents. If your authority mentions: packaging tape, plastic straws, takeaway tubs, ketchup bottles and picnic ware then it is recyclable.
- Check the resin code number but the vast majority of thin, flexible, lighweight packaging is made of LDPE if not PET.
- PP is slightly harder and more heat resistant than LDPE/HDPE. It is tough and flexible.
- Stable use temperature -0°C to 82°C
- PP is rarely recycled but, when it is, it is recycled into bike parts, bike racks, seats, brushes, cables and trays.
- PP is non-biodegradable
Number 6: PS - Polystyrene
There are two main forms of PS (hard, brittle PS and expanded PS, which is light, insulating and structurally weak). Expanded PS should be handled with care because it breaks-up into the environment. This plastic should always be avoided. PS is considered less safe due to the effects of leaching carcinogens into food/drinks.
- PS is non-recyclable and should not be reused.
- To avoid leaching of carcinogenics: do not use PS for food containers or bottles and do not microwave food in PS containers,
- PS comes in different forms with different properties (sheets or moulded PS with impact resistance, foams, expanded PS foams)
- Stable use temperature - varies but typically <60°C
- PS is non-biodegradable
Number 7: Alternatives and biodegradable composites
Plastics with a resin code of 7 do not fall under one of the previous 6 categories and include nylon, polycarbonate, composite plastics, BPA etc. and are found in food containers, signs, bottles, displays, signs, sunglasses and electronic devices. Resin code 7 plastics are non-recyclable, but it is important to check the label for instructions on disposal. The good news is that if a plastic is biodegradable, it will fall under this category. But not all number 7 plastics are biodegradable.
- Check the packaging label for disposal instructions.
- Properties vary widely.
- Do not reuse for food or drinks unless the label says this is safe to do so. Some plastics will be bad for the health due to bacterial growth and the leaching of carcinogens.
- Do not microwave unless the packaging says it is safe to do so. Operating temperatures will vary.
- If the label says PLA then it is reusable and compostable. PLA is a bio-based polymer derived from corn starch and is one of the most environmentally friendly choices. PLA is compostable but non-recyclable.
Non-plastic items and doubts about recycling
I soon hope to add an article about the recycling measures of other materials that are non-polymeric. For now, though...
If you are still unsure on if a product is recycled, collected by your local waste program or where your nearest recycle location is, then the best advice I can give is to check the "Recycle Locator" (click on this link)