How can we improve recycling rates? A new perspective.

Aug 25, 2023

Last Updated: Aug 26, 2023

This is not going to be your usual #recycleright piece: in fact it is the opposite. This is also not a puff piece but a position paper of sorts. If you are looking for quick tips or lighthearted info, you should skip this one! This piece is in response to the question we are constantly asked: how can we improve recycling rates. Note that this focuses specifically on post-consumer waste from households. There are other low-hanging fruit not discussed here which may be covered in future articles.

It's the System

There are major systemic reasons for Singapore's low recycling rates. 

Low and dropping recycling rates are not due primarily to a lack of education and poor practices by consumers. While it is absolutely true many consumers are putting the wrong things into the blue bins, it's impossible to say that this is the primary issue or that this behaviour is getting worse.

Note that this is an analysis of post-consumer waste recycling and not industrial waste recycling1.

Collection Process

Before diving in, it's important to understand that recycling is a business, and that the public waste collectors (Alba, 800 Super & Sembwaste) do not do recycling: they simply collect recyclables, have them sorted, and try to sell them to actual recycling companies. 

Understanding the collection process in Singapore is essential. 

Here's a brief overview:

  1. Consumers: Put mixed recyclables in blue bins.
  2. Recycling Trucks: Collect the contents of those bins.
  3. Sorting Plant (MRF): Waste is taken to a Material Recovery Facility (MRF).
  4. Extraction at MRF: Metal is extracted automatically with magnets and eddy currents; paper is extracted through both automated and manual methods; glass and plastic are extracted manually. The manual extraction is done by workers who take materials off a fast-moving conveyor belt.
  5. Baling: The sorted materials are baled or collected in containers.
  6. Selling to Recycling Companies: The bales/containers are sold to recycling companies. Demand is affected by (1) the purity of the bales (ie how well it is sorted) (2) the market price (3) transport costs. Glass is the exception (see below).
  7. Incineration: Any material not baled or sold is sent for incineration.



  • Widely accepted: These are the easiest to recycle and have the highest market value and thus the highest recycling rates. 
  • Easy to process: Metals are easy to extract at the MRF. Due to the properties of metals, they can be extracted automatically with magnets and eddy currents.


  • Easily sorted: Paper is extracted both automatically and manually at the MRF. The shape of paper and its light weight makes it easy to extract with airlift separators. 
  • Positive market value: There is a buoyant market for waste paper with secondary markets in different grades of paper
  • One major drawback: Paper is easily contaminated by food waste and so suffers considerably when blue bins are misused.


  • Sorting Challenges: It is difficult to sort and extract plastic at the MRF due to the many different shapes, sizes, and types of plastic. Only certain types of plastic are technically recyclable (in particular PET, HDPE, LDPE and PP) however it is not always easy to tell one plastic from another. This in turn makes it extremely difficult to separate plastics into bales of uniform quality that meet the specifications of recycling companies. In other words, if you cannot sort your plastic to high levels of purity, companies won't buy the bales from you. 
  • Example of Sorting Difficulty: Some plastics are easy to identify, while others are not. For instance a PET water bottle is easy to identify and therefore has a better chance of being extracted, baled and sold. On the other hand, imagine you have a PET plastic cup whizzing by you on the conveyor belt. It is technically recyclable, but given its shape, it might be hard to distinguish it from a polypropylene cup, or a cup of some other plastic. In this case, the challenge of sorting becomes a hurdle to this cup getting recycled. Such an object is far less likely to be plucked from the conveyor belt to be baled and sold. 
  • Relatively high processing costs: The margins on waste plastic are extremely thin in comparison to the costs involved in collecting it, sorting it, and transporting it to recycling facilities.
  • Low Market Value: Virgin plastic costs far less to produce than recycled plastic. 
  • Low Market Value Challenges: This low market value creates another recycling hurdle. When you put plastic into a segregated recycling bin, i.e. a bin that specifically says that it is for plastic only, there is a higher chance that it will end up in a general waste bin (trash) because it is a loss maker for collection companies. Meaning that some waste collectors maximize profits by throwing the plastic out instead of trying to get it recycled.
  • Global Perspective on Plastic: It’s worth noting that these issues are global. Plastic, for the reasons cited above, has always been difficult to recycle.
  • Reversed vending machines: The introduction of Reverse vending machines should go a long way to improving recycling rates for PET plastic bottles as these will ensure purity of this particular waste. This is an excellent example of a technological solution. But for now, there is no such solution for other types of waste plastic.


  • Heavy and Expensive to Transport: Glass is extremely heavy (relative to its alternatives) and thus has a relatively high cost of freight. This in turn results in a “negative market value”, meaning that nobody will pay us for our glass:  we have to pay people to take it away. Singapore’s waste glass is mostly exported to Malaysia.
  • Negative Market Value Challenges: Very few waste management companies want to deal with glass due to its negative market value. Public waste collectors who collect blue bins have an obligation to handle these materials under their NEA contract, but more specialized operators, called “general waste collectors”, would rather not touch these materials. There is an economic incentive for such operators to throw glass into general waste. 
  • Global Perspective on Glass: It's worth noting that these problems are not unique to Singapore. Globally, glass has become an unattractive material to recycle. 
  • A side note for consumers: Glass is unsustainable as a single-use material. While many think of glass as the perfect material because it is infinitely recyclable, its negative value makes it extremely difficult to recycle in practice. Additionally, glass requires being heated to 1500°C to manufacture and then heated to 1500°C again to melt it down for new objects. This makes it a very carbon-intensive material. Once prized for its recyclability, glass is now too expensive for most places to recycle, with virgin glass being cheaper than recycled glass.

Lack of Investment in Sorting Technology

One of the big problems evident above is that Singapore does not invest in cutting-edge sorting technology. So when recyclables are sent to an MRF, they are not sorted at purity levels that make the recyclables attractive to buyers in the secondary market for post-consumer waste. 

  • Lack of Technology: We do not use optical sorting devices or other cutting edge technology as seen in countries with very high recycling rates like Germany. Recyclables are put on a conveyor belt and a handful of workers manually pluck materials off.
  • Facilities: In Singapore, the three public waste collectors send their recyclables to one of two facilities. We don't have insight into the facility run by Sembcorp; however, the facility used by Alba and 800 Super has only 10 manual workers on the conveyor belt line. This seems like very little resources to maximise value extraction.


Transportation plays a crucial role in the recycling process, and is a factor that can significantly impact the recycling rates in Singapore.

  • Freight Costs: If a material succeeds in getting baled, it still needs to be purchased in the open market. Recycling companies are almost all located overseas, be it across the border in Malaysia, in the region, or even in China. This means that freight costs become a significant factor in whether or not our waste material is attractive to buyers.
  • Impact on Recycling Rates: Recently, we learned that recycling rates for Singapore dropped in 2022. Was it due to consumers' mistakes? No! In fact the National Environment Agency (NEA) clearly stated this was due to increased freight costs, which made it difficult to sell our recyclables. The issue was not that people were doing worse at sorting their recycling, but in fact, the drop was due to a factor completely out of consumers' control.

Are we getting worse at recycling? Who knows?!

The only way to really know if Singaporeans are doing better or worse at recycling is to random sample blue bins. 

Currently, the way recyclables are collected doesn't allow for accurate sampling. Recycling trucks show up at the Material Recovery Facility (MRF) and dump their waste. The fact that a lot of it ends up incinerated is not a clear indication of how much of what was put in the blue bin was wrong. A lot of the material may be filtered out due to difficulties with sorting or lack of market value.


It is foolish to keep blaming low recycling rates on consumers without addressing the systemic barriers to high recycling rates. 

For close to 10 years, we have been scolding consumers without addressing the real elephants in the room. The strategy of focusing solely on consumer education has, by now, proven to be a failure. It is time to accept that rates are not going to magically jump up without some very different approaches. 

If we cannot adapt consumers to the system, it is time to adapt the system to consumers: we need to look at how we can make the system more resilient to contamination. 

The solution will involve a few key areas

  • Better information and research
    • We need to stop thinking of plastic as one material and recognise that not all plastics are created equally. We need better information on what is happening to the different types of post-consumer plastic wastes to truly understand what the challenges are.
    • Likewise when consumer strategies are being tested, we need to use tools like blue bin sampling and a/b testing to ensure that proposed solutions are truly impactful. 
  • Discontinue systemic wishcycling: be realistic about plastic
    • If a material has no ready market for recycling, it is pointless to collect it and to ask consumers to recycle it. This is wishcycling on a grand scale.
    • The problems with plastics in particular need to be addressed: 
      • much food contamination arrives in the recycling system on plastic
      • plastics have the lowest recycling rates
      • many post-consumer plastics are not recycled at all
      • plastic is the most confusing for consumers to recycle. 
    • We need to rethink what, if any, plastics should go in blue bins3. Simplifying plastic recycling could potentially boost overall recycling rates by (1) lowering food contamination of other materials and (2) reducing consumer confusion.
  • Investment
    • Any meaningful improvement in recycling rates will likely require some investment in the kind of sorting technology used by the countries most successful in this area.

Having tried to fix consumers for all these years, it is time to point the finger at other obstacles and to start thinking creatively about how else the system can be tweaked or retooled to work better.



Note 1: Do note that all of these comments are specific to post-consumer waste, meaning the waste that is produced in households. The issue with this kind of waste is that it is all mixed together, and it is hard to sort into bales of high quality. Industrial waste, on the other hand, tends to come in large homogeneous quantities and is much easier to get recycled due to the quality of this material. To the extent that we can get consumer waste into high-quality and high-purity bales, it will get recycled. So the plan to have, for instance, reversed vending machines for PET plastic bottles should go some way to ensuring that the recycling rate for PET plastic bottles goes way up.

Note 2: Some people have suggested that the creation of a domestic recycling industry would boost recycling rates by avoiding international freight costs. There are a couple of key reasons why this is unlikely to work:

  1. High property costs and rentals in Singapore make low margin businesses like recycling uneconomical. That is the reason our recycling is done in other countries in the first place.
  2. Singapore does not have a large manufacturing sector. So the raw  recycled plastic would still need to be shipped overseas. We simply don’t have enough domestic manufacturing capacity to absorb all the recyclable waste we produce.

Note 3: One strategy we have suggested at is to ask consumers to only recycle plastic bottles. These are predominantly PET and HDPE and not only have the best chance of being recycled but also are easy for consumers to identify. 

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