06 March, 2018
SINGAPORE — Often touted as “greener” alternatives to plastic bags, paper and degradable bags may not actually be better for the environment — at least not in Singapore’s case.
Compared to plastic bags, they may require as much resources to produce and have a similar environmental impact, as waste here is incinerated before going to the landfill and not left to decay.
Revealing the findings of a study commissioned by the National Environment Agency (NEA) on Tuesday (March 6), Senior Minister of State (Environment and Water Resources) Amy Khor said the authorities would thus not impose a charge on plastic bags.
“Imposing a charge or ban on disposable plastic bags and substituting them with other types of disposable bags is unlikely to improve environmental outcomes,” said Dr Khor.
Whether retailers should charge for plastic bags to curb excessive consumption has been a long-running debate here. Last year, four major supermarket chains were reportedly in talks to charge for plastic bags.
The study – by National University of Singapore academic Kua Harn Wei – concluded that consumers could reduce their environmental impact by often using reusable bags and food containers instead of disposables.
The paper, LDPE, non-woven PP and cotton bags should be reused at least 3, 4, 11 and 131 times respectively to ensure that they have lower global warming potential than conventional HDPE carrier bags that are not reused.Dr Khor said the Government will step up engagement with stakeholders.
Some of its measures include disallowing the use of disposables for dine-in customers at new hawker centres, such as at Our Tampines Hub, Pasir Ris Central and Yishun Park. The rule will also apply at 13 other new hawker centres that will open by 2027.
Dr Khor was responding to questions by some Members of Parliament. Ms Cheng Li Hui (Tampines) and Non-Constituency MP Dennis Tan asked about the possibility of imposing a levy to cut excessive use of plastic bags.
Packaging waste made up a third of the 1.67 million tonnes of domestic waste generated here last year.
About 15 per cent of the packaging waste – or about 83,550 tonnes – is made up of plastic and paper disposables, such as single-use plates and take-away food containers.
Dr Kua’s study, which began in Sept 2016, found that plastic bags designed for a one-time use had the biggest impact on the environment. Greenhouse gases are generated to make them from fossil fuels (crude oil), and when the bags are incinerated.
Some businesses offer oxo-degradable bags as a more eco-friendly alternative. But the additives that help to speed up the degradation process could interfere with the recycling process when mixed with conventional plastics.
They also require a similar amount of resources to manufacture as plastic bags.
Paper bags are derived from trees and require a large volume of water to produce. They are also unable to bag wet items.
A reusable bag used over a year could save 125 plastic or degradable bags, or 52 paper bags, Dr Kua found.
[It will take a dedicated eco-warrior to reuse a bag over a year. Most people don't reuse eco-bags more than a few times. If they remember. Maybe it is a matter of developing the habit. But even so, reusable bags need to be cleaned regularly or they present a health hazard. Also what does it mean that "a reusable bag used over a year could save 125 bags"? Is this the number of occasions it could replace a plastic bag? Or that the resources to make 125 bags is approximately equal to the resources needed to make a reusable bag? And that at 125 bags the reusable bag "breaks even"?
Because of the resources needed to produce the materials for cotton totes, the study measured a cotton bag’s total footprint (including growing, manufacturing, and transportation) at a whopping 598.6 lbs of CO2. The standard HDPE bag, on the other hand, emits 3.48 lbs. ]“Taking into consideration both the monetised cost and environmental impact, reusable bags emerged as the most environmentally-friendly option for carrying groceries and similar items,” said the NEA.
The study also found single-use plastic plates and containers generated the most greenhouse gases and consumed the most energy.
Paper plates require large tracts of forest land to be modified, while single-use paper boxes with plastic lining are energy-intensive to make.
Biodegradable corn-starch containers are becoming more common in Singapore. But forests may be cleared and large amounts of water are needed to grow the corn.
Meanwhile, the environmental impact of polystyrene was found to be lower, but they use up Singapore’s limited landfill space.
[Not if you incinerate them first.]
Porcelain plates or reusable containers used over five years could replace 3,650 single-use containers, Dr Kua found.
[I suspect Dr Kua is just doing "accounting" work. If you use a plate for 5 years, twice a day, you would not need to use 3650 disposable (365 X 5 X 2). Thank you very much. We can do simple math. What we would like to know is, what is the carbon footprint for making ONE porcelain plate and washing it regularly, and the carbon footprint of 3650 disposables. IF a porcelain plate has the carbon footprint of 5000 disposables, then it would need to be used more than 5 years or more than 5000 times to offset the carbon footprint of 5000 disposables. If you break the plate and cannot use it after 200 times, you are in net deficit. It would have made more sense (environmentally) to use disposables.]
Dr Khor said the Government will reduce packaging waste upstream. By 2021, businesses will have to report the type and amount of packaging they put on the market and their plans for reduction. Industry consultations will start this year.
To NCMP Leon Perera’s question on microplastics – part of the growing problem worldwide of marine trash – Dr Khor pointed to anti-littering laws and beach clean-ups.
During the treatment of used water, microbeads, a form of microplastics, are also “substantially removed as sludge and disposed of by incineration”, she said.