top of page

Trash talk: the rubbish behind "recycling" numbers

Updated: Jun 26, 2021

These symbols on your everyday plastic items tell you that you can recycle them. Or do they?

Be they on your food containers, liquid laundry detergent, or shampoo bottle, you will be quite familiar with the little numbers usually on the underside of your household plastic products. You've been told to rinse and dispose of in the blue bin, and the little arrows comfort you in this decision that you are recycling right. We can tell you what each number means, and we will, but that won't help you get your plastics recycled.

A little history

The symbols —a triangle with a number from 1 to 7 inside— we developed in 1988 by the organization now known as the Plastics Industry Association and collectively called the Resin Identification Code (RICs, which the recycling and plastics industry pronounces “Ricks”). Currently, they go by the official name ASTM International Resin Identification Coding System and are administered by the organization of the same name, ASTM International. The latter is responsible for designing and setting the standards for a wide range of industries. In 1988, the symbols started out as just 3 bent arrows, shaped in a triangle form. We still see those around and you are likely familiar with them. They were developed for the industry and not actually for us consumers. Six types of plastics were included, with the seventh category (number 7) throwing in all the remaining plastics into the same group. The aim was to help manufacturers develop some consistency in the materials they used for packaging with specific information about the properties and recyclability of their products. So you'll never see them on any other material.

So does the number help me know what gets recycled?

Countries and sometimes states within them have their own recycling programs which is why the triangular symbols and numbers on plastics won't always help you depending on where you live. The issue with RICs:

1. The RICs are not always on plastic

For one, your packaging might very well be made from one of the plastics categorised in the series, but that doesn't mean that it will necessarily have the number inscribed on it. It might, and it just as likely might not. It's not internationally mandatory! So you may also have plastic in your hands that has no marking on it but that is recyclable.

2. Plastics with a number code are not always recyclable

Also known as the “plastic numbers” or unfortunately as the “recycling numbers”, it might come to you as a surprise to know that those 3 triangular arrows don't mean that a material is, in fact, going to get recycled if you put it in the blue bin. Wait, whaaaat? The three bent arrows were so confusing that in 2013 the ASTM changed them to a solid triangle, to better reflect that the code indicated the material type and not an indicator that a particular plastic will be accepted at your country or area's recycling facility (or in Singapore, by our waste collectors and Material Recovery Facility - the MRF). This is without talking about plastic contamination, which is a different topic, and one not for today. But still, there is another problem...

3. The standards are not the same worldwide

So you still can't trust the recycling arrows! RICs are required by law in 39 states of the USA for example, as each state writes statutes in its own way with its own requirements and many of them specifically require numbers with chasing arrows and specific letters to correspond to their own recycling schemes. So while the international standard changed, state laws did not and it's yet another story for countries across the globe. So depending on where you are traveling to, you could see a mix of everything being used. It's also a headache for companies who need to comply with the varying requirements where they sell their products in.

But it's recyclable so it can get recycled

Again, not so fast. Recyclability doesn't mean that it will get recycled. There are many factors that come into play that determine whether or not the material will get recycled, and the defining one (beyond whether the technology exists) is whether it makes economic sense. Everything starts at the previously mentioned materials recovery facilities which sorts waste into its constituent parts, but from there, it's a labyrinthine network of brokers and traders. Plastics who make it past this point are all sent abroad. But in 2018, China, the world’s largest market for recycled plastic, prohibited 24 types of waste from entering the country under their National Sword policy. It seemed to coincide quite well with the release of "Plastic China", a documentary film that went viral (before being censored in China), disclosing some of the recycling industry's worst realities - both a threat to recyclers' health, and safety and to the environment. What did this mean for the rest of the world, including Singapore? Without someone to sell to, the price of the recovered materials plummeted. Every country started overflowing with unwanted plastics (among other materials) that they couldn't find buyers for.

So, should I bother knowing the plastic numbers?

Yes, provided you are now the owner of this packaging you have in your hands, it's still important to know them so as to use and dispose of them in the most responsible way available to you. Just remember: as long as we rely on exporting our plastic waste to other countries and demand, we cannot ensure that what we collect gets recycled. If it costs more to recycle than to burn, then we can expect to see increasing incineration in the years to come.

Plastic number 1

Polyethylene Terephthalate (PET or PETE)

It's clear, quite tough. Never put hot water in these bottles by the way, as their melting point is around 85 degrees Celsius.

  • carbonated and non-carbonated soft drinks bottles (remove the PVC shrink labels and the HDPE bottle caps for ease of sorting)

  • fruit juice and concentrate bottles

  • egg cases

  • salad dressing, peanut butter, and vegetable oil containers

  • mouthwash bottles

Fun fact: did you know that a lot of our clothes, especially sportswear, are made from PET fibres? As it stands, PET is one of the most recycled materials, and the increase in demand for rPET (recycled PET) is on the rise, especially for drink manufacturers and fashion brands who are setting targets for use of recycled content in their products. For example, in January last year, adidas announced a commitment to increase the content of recycled polyester (rPET) in its garments to 50 percent before the end of the year, and to use only recycled polyester across its supply chain by 2024.

Plastic number 2

High-Density Polyethylene (HDPE)

This plastic offers both hard and semi-rigid properties, is a little waxy and opaque. It's more resistant to temperature variations than PET. You're familiar with this one in the form of bathroom-related products but also household detergents and food containers. Examples:

  • shampoo, body wash, facial wash bottles

  • bleach bottles, buckets

  • milk jugs

  • white butter and yogurt tubs

  • crinkly plastic bags (inside cereal boxes) and some shopping and trash bags

  • Note: bottle caps, in their variety of colours, are harder to recycle, and often recyclers will not take them

As mentioned above, when brand owners continue to demand postconsumer recycled material to meet their commitments on the use of recycled content (despite the fact that recycled postconsumer HDPE can be much more expensive) it lays a more hopeful path for recycling.

A quick reminder about plastic bags: never submit for recycling those that have oxo-degradable or bio-degradable claims. Use them for your trash only. They will typically be either number 2 or number 4.

And the other plastics? Their fate is a lot less certain.

Plastic number 3

Unplasticised Polyvinyl Chloride and plasticised Polyvinyl Chloride (both referred to as PVC).

Unplasticised: hard and rigid, can be clear. Plasticised: flexible, elastic and clear.

  • Unplasticised: some fruit juice and cordial bottles

  • Plasticised: shoe soles, watch straps, rainwear ( unlikely something you will find in the kitchen)

♶ Plastic number 4

Low-Density Polyethylene (LDPE)

Thermoplastic is soft, flexible with a translucent waxy surface. It can be made rigid too. Usually for plastic films and items that need flexible plastic packaging such as

  • plastic wrap, or “polybag,” that protects magazines, newspapers or books

  • Shrink-wrap and stretch film

  • film for packet drinks

  • squeeze bottles (the type we use for soy sauce and vinegar at the foodcourt)

  • cling wrap and sandwich bags

  • frozen food bags

  • dry cleaning bags

  • most bubble wrap

  • bread bags (almost all made of #4 to the exception of the plastic clip that often accompanies them to reseal the bags)

Plastic number 5

Polypropylene (PP)

Hard, flexible, translucent, or completely clear and is often chosen for bottles and containers susceptible to be used for hot liquids as it has a high melting point.

  • takeaway boxes and lids (the ones you most commonly get at the restaurant to dabao, not the styrofoam which is expanded polystyrene, EPS)

  • carpet fibre, toys, furniture, appliances (yes, basically a lot of stuff)

♸ Plastic number 6

Polystyrene (PS) and Expanded Polystyrene (EPS)

Can be clear and glassy, it's very brittle and breaks easily. We don't recover the EPS form of this plastic here, the foamy white packaging which you will erroneously call Styrofoam, the name of a Dow-trademarked brand of polystyrene insulation. So no clamshells, hawker boxes or cups, or containers used for fresh fish and meat. They are usually food-contaminated and not accepted to the MRF. On the other hand, if you take your clothes for dry cleaning or spend your days at ION, you will be familiar with the polystyrene clothes hangers. Try to send them back to your dry cleaner or leave them in store.

💿 What about CDs and DVDs?

"The NEA says I can recycle those!" These media are made of plastic, but not the same kind of plastic as bottles and food containers and are a mix of different plastic resins. So yes, in Singapore we accept them but they are a combination of the above categories! The cases are polystyrene (plastic #6 ) and the discs are polycarbonate (plastic #7). StarHub for example started their e-waste recycling programme RENEW back in 2012, whose RENEW collection bins (nearly 160 as of January 2021) can be found here. The company TES then is responsible for the recycling alongside other e-waste components.

So there you have it. The truth about the famous plastic numbers and how they are not an indicator of local recyclability, but how they’re still important to know to help you figure out what they’re made from. Bottom line? Avoid disposables, reduce and reuse as much as possible!

Let's stay in touch

Like our blog and information? Then sign up for our updates and to learn more on sustainable living - the practical way.

bottom of page