This list of Frequently Asked Questions is a compilation of readers’ questions sent in to zerowaste.dabao@gmail.com, and our own questions that have popped up along the way. It’s a working, living document and we invite you to contribute your own questions too!


What happens to Singapore’s plastic waste*?
*Noting that waste is not waste unless it is wasted! We can give plastic a new lease of life by recycling it .
According to the Ministry of the Environment and Water Resources’ Key Environmental Statistics 2012, 730,000 tonnes of plastic waste was generated in 2010, with a recycling rate of just 11% (only 2% up from 2008). Plastic that is not recovered for recycling gets incinerated and landfilled.


How does plastic waste get recycled?
Paraphrasing Zero Waste SG’s great guide to recycling plastic,

Plastic waste can be divided into pre-consumer and post-consumer plastic waste.
Pre-consumer: Plastic scraps generated by companies during the manufacturing of products. These plastics are usually easier to recycle as they are clean and homogeneous.
Post-consumer: Generated by consumers after use. They are more difficult to collect, easily contaminated with food, and not homogeneous.

Whether pre- or post-consumer, once collected, plastic waste is separated into seven categories developed by the US Society of the Plastics Industry (SPI):

1. PET (Polyethylene terephthalate) – Used for water bottles, soft drink and cooking oil bottles, and meal trays.
2. HDPE (High density polyethylene) – Used for milk and detergent bottles.
3. PVC (Polyvinyl chloride) – Used for plastic pipes, food trays, shrink wrap, and bottles.
4. LDPE (Low density polyethylene) – Used for plastic bags and bin liners.
5. PP (Polypropylene) – Used for bottle caps, margarine tubs, and meal trays.
6. PS (Polystyrene) – Used for food containers, egg cartons, vending cups, plastic cutlery, and protective packaging for electronic goods.
7. OTHER – Includes any other plastic that does not fall into the above categories.

After sorting, plastic waste is baled and exported overseas for recycling. There are also plastic recycling companies in Singapore that sort and process plastic waste into small pellets to be used as feedstock for making plastic products.


Why should we reduce and recycle our plastic waste?

1. It is estimated that 4% of the world’s annual oil production is used as feedstock for plastics production.
2. It is estimated that an additional 3-4% of the world’s annual oil production is used for the manufacturing of plastics.
3. When incinerated, plastics release CO2 and potentially toxic gases such as dioxins.
4. Plastics are non-biodegradable and take hundreds of years to break down. When they are landfilled, they take up valuable landfill space that Singapore just doesn’t have.


What are bio-plastics?

Bio-plastics are an alternative to conventional plastics, derived from renewable biomass sources, such as agricultural by-products and corn starch.

It is argued that the production and use of bio-plastics are more sustainable activities than the production and use of conventional plastics because bio-plastics use less petrol-based feedstock and emit less CO2 and no/fewer toxic gases when incinerated.

It’s important to ask how much non-renewable energy and water goes into powering farm machinery, irrigating farms, producing pesticides and fertilizers, and transporting and processing crops. Only then can a more accurate comparison between conventional plastics and bio-plastics be done. (I’m personally a bigger fan of the use of agricultural by-products because it seems to avoid these issues.)

There are different types of bio-plastics, each with their own pros and cons. As I mentioned, some of them make use of agricultural by-products, whilst others use crops grown for the production of bio-plastics. Some are made purely from biomass sources (polylactic acid, PLA), whilst others are a mixture of biomass and conventional plastic (such as polypropylene, PP). Certain bio-plastics are biodegradable and compostable, others are only biodegradable, and some are neither. The recycling of bio-plastics is in its infancy – it can only really take off when the necessary recycling infrastructure is put in place. In Singapore, bio-plastics cannot yet be recycled.

A good look into all these factors is needed before we categorically declare all bio-plastics as the Next Green Thing. We need to look at life cycle assessments that take into account comprehensive cradle-to-grave energy/water/land usage, greenhouse gas emissions, and toxic waste emissions. An example is this University of California, Santa Barbara study that assesses the life cycles of plastic yogurt containers made of polystyrene (PS) versus plastic yogurt containers made of PLA. Its major finding is that the PLA containers release 48% less carbon than PS ones, providing the basis for Stonyfield Farm’s decision to switch over to PLA yogurt containers.

Here’s more from Stonyfield Farm and more about other types of sustainable packaging.


So what’s the deal with biodegradability and compostability?

First, a distinction should be made between the two: biodegradability simply refers to the ability to be consumed by microorganisms and decomposed back down into compounds found in nature, whilst compostability refers to the ability to biodegrade quickly in a composting pile. A composting facility optimizes surrounding conditions, i.e. humidity, temperature and lighting, so that waste can be efficiently converted into humus, which can then be used as a nutrient-rich fertilizer for farming.

Singapore incinerates all waste that is not recycled, and landfills the remaining ashes. There are no large-scale composting facilities in Singapore* (since the recent closing down of IUT Global), though some great groups have taken it upon themselves to start their own compost piles (big applause!). As such, I’ve been asked a number of times if biodegradable and compostable food packaging products are even relevant here.

I believe they are, but not because of those properties in particular. Olive Green’s cornware, for example, may be 100% biodegradable, but it is because it uses less petrol-based feedstock (it’s 90% biomass-based, and 10% plastic) and releases less COand no toxic gases when incinerated, that I consider it a promising alternative to conventional pure plastic.

*At the Tuas Incineration Plant, I asked the operations engineer leading the tour whether another food waste-to-energy recycling plant might be in the works for the future. He said there might be plans for one – I certainly hope so! I’ve had the chance to eat apples grown in an orchard that uses the compost collected from my house at Vassar, and I hope to one day do something similar in Singapore :) .


Is disposable paper better than disposable plastic packaging?

Not necessarily! Lots of people automatically assume that because paper comes from a supposedly renewable source – trees – they must inherently be better for the environment than plastic. But the paper manufacturing process can be very energy-intensive and polluting (it uses up lots of clean water and dispels lots of dirty water). It’s also important to consider the source of the paper pulp, e.g. Is it from a sustainably maintained forest, such as a Forest Stewardship Council-certified forest? Homegrown green paper packaging leader Microwave Packaging in Singapore uses FSC-certified paper in its products. The paper is brought in from the U.S., though, so we do have to consider the emissions involved in such long-distance transport.

These links provide further insight:



The answer takes a different turn, however, when we consider paper made of recycled fibres instead of virgin paper pulp. To paraphrase sources found on Zero Waste SG’s informative article:

“Producing recycled paper involves between 28 – 70% less energy consumption than virgin paper and uses less water. This is because most of the energy used in paper-making is the pulping needed to turn wood into paper. Recycled paper produces fewer polluting emissions to air and water. Recycled paper is not usually re-bleached and where it is, oxygen rather than chlorine is usually used. This reduces the amount of dioxins which are released into the environment as a by-product of the chlorine bleaching processes.” (Waste Online)

“Paper recycling leads to savings in the use of raw materials for pulp and paper production and less wood is used. This should result in less intensive forest management and take the pressure off exploitation of old growth forests, vitally important for their biodiversity.” (Friends of the Earth)

Some cool recycled paper products in Singapore include Ng Pei Kang of Geometria’s beautiful “Ta pao, no plastic” disposable paper food packaging, and the labels from bloomerang we used for our special-edition Operation Zero Waste Dabao L’earth lunchboxes :).


What about BPA (bisphenol-A) in plastic? Is it bad for my health?

Paraphrasing Mayo Clinic’s article,

BPA is an industrial chemical used to make certain plastics and resins. BPA is found in some food-contact containers.

Some research has shown that BPA can seep into food or beverages from containers that are made with BPA. Exposure to BPA is a concern because of possible health effects of BPA on the brain, behavior and prostate gland of fetuses, infants and children.

However, the U.S. Food and Drug Administration has said that BPA is safe at the very low levels that occur in some foods. The Agri-Food & Veterinary Authority of Singapore has a similar stance: “Proper usage of the plastics will have insignificant or very low levels of chemical migration, which does not pose any health risk to consumers even after long-term use.” Here’s the AVA’s response to a concerned parent’s letter regarding the safety of plastic baby bottles, and its guidelines for safe use of plastic.

To err on the side of caution, choose products that are labelled BPA-free, such as those from L’earth.


I want to avoid disposables altogether, and go for reusable containers and bottles instead. Should I opt for plastic, glass, aluminium, stainless steel, or porcelain?

This is a tough one! The jury still seems to be out on which material is best. This study comparing plastic vs. aluminium vs. stainless steel reusable bottles is pro-plastic, measuring environmental impact in terms of water use, contribution to global warming, and solid waste. This one opts for plastic over glass, looking at energy usage, air pollution, waste production, and global warming potential. However, there are studies that strongly advocate glass instead of plastic, while others, such as this study on plastic vs. paper vs. glass milk cartons (yes, it looks at disposables not reusables, but it’s still relevant!), suggest glass is better… but not in all aspects.

To quote the latter source, “As with many environmental quandaries, the answer depends on whether you care more about climate change or solid waste, chemicals in the ground water or human toxicity, acid rain or smog.”

It’s complicated, but a good first step is simply avoiding disposables and reaching for reusables, of whichever material, then learning how best to reuse, recycle and dispose of your chosen type of reusable containers.


Reusables need to be washed with water, and some reusable materials are manufactured using quite energy-intensive processes. Are reusables really better than one-use disposables?

We really have to look at a whole range of concerns, and also rank how important each concern is to us in our local and global contexts. Some concerns include:
– energy wastage
– landfill impact
– greenhouse gas emissions
– unsustainable extraction of petroleum
– water wastage
E.g. From an energy point of view, it takes the same amount of energy to manufacture and wash a glass cup 15 times, as it takes to manufacture and dispose of 15 paper cups. So if you use your glass more than 15 times, it’s more energy-efficient to go with reusable glass than with paper cups (http://greenresearch.com/2009/07/16/reusable-vs-disposable-cups-saving-money-and-energy/).
Here in Singapore, the amount of landfill space that disposables take up is arguably a higher priority than in less land-scarce countries. Even though there are some costs in terms of water usage, reusables ultimately save on landfill space. We also need to look at the specific type of disposables/reusables in question: paper, plastic, glass, etc. Each one has a different cradle-to-grave (or cradle-to-cradle, if we include recycling/material reutilization) process. I guess the lesson here is not to follow environmental trends blindly, but to do some proper research and practice constant vigilance, à la “Mad-Eye” Moody!

One thought on “F.A.Q.

  1. Pingback: Operation Zero Waste Dabao | Photos of our NOT THE LANDFILL Picnic (Aug 4)

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