What is the best way to dispose of plastic?
Is there perhaps another option we aren’t considering?
The answer is – it depends.
In this guide, we look at what the best way to manage plastic waste might be, according to environmental, economic and other measures.
Summary – What Is The Best Way To Dispose Of Plastic?
It depends on several factors
Just a few of those factors might include the plastic type (LDPE, PVC, etc.), the plastic product or item (plastic bag, plastic straw, etc.), the waste disposal technology and systems available (how advanced and eco friendly is the incineration technology, or recycling facility being used in a particular city), and other factors
It also depends on what measure you are measuring ‘best’ by … environmental, economic, human health/social, practical?
Even with just environmental measures – there are many different ways to measure eco friendly – greenhouse gas emissions, water use, energy use, waste by products, and so on
But, in general …
Environmentally, going zero waste (not using plastic in the first place) is might be the best approach.
Second might be re-using the plastic item or material as many times as you can before throwing it away or disposing of it (and in the case of plastic bags, using it as a bin liner after you can’t use it for shopping any more for example).
After that, recycling is seen by some studies as being the most environmentally friendly, whilst other studies see incineration as the most environmentally friendly option specifically for plastic bags (where other plastic items are not taken into account).
Practically, only some types plastics can be recycled at all, so, non recyclable plastics may benefit from going to landfill or incineration.
Economically, only some plastics can be recycled at a profit, and in some local markets, recycling as a whole creates more job than dumping waste in landfills.
Also economically, some incineration plants are expensive in terms of capital set up and raw costs.
There’s also the measure of cost per tonne of each disposal method.
From a human health perspective, the incineration of plastic has potential to release air pollution contaminants if incineration technology isn’t able to flue or capture them.
There is potential to impact human health here (from outdoor air pollution).
Plastic in landfill may also be at risk of contaminating soil and water sources if leachate leaks from the landfill site.
Plastic can also escape from unsecure or open landfills and pollute the land and ocean, where it has potential to break down into micro and nano plastics and get into food and water supplies.
Overall, eliminating waste, minimising waste, and re-using plastic items might be the best options where possible.
This is especially true where plastic can easily be eliminated or substituted or re-used for non critical applications.
But, if plastic has to be disposed of – there appears to be pros and cons to each waste management option, and these pros and cons might differ between countries and individual cities.
All three options may be used in different proportions (for different plastic types and products and items) depending on local conditions, factors, variables and context
What Is The Most Environmentally Friendly Way To Dispose Of Plastic
There’s many ways you can measure environmental impact in different water sources, in the air and atmosphere, on land, and so on.
So, the most environmentally friendly way to dispose of plastic may change depending on the environmental measure you are assessing.
But, for the purposes of this guide, we refer to two separate reports:
- https://ourworldindata.org/faq-on-plastics#recycling-landfill-or-incineration-which-should-we-choose [Recycling, landfill, or incineration: Which Should We Choose? – from FAQ on Plastics Guide]
In this report, they look at the best way to dispose of plastic when taking into account global warming potential, and energy use of each disposal method.
What they find is “Recycling had the lowest global warming potential and energy use across nearly all of the studies. From an environmental perspective, recycling is usually the best option”
But, this finding is based on the conditions or notes that
1. Recycled material is a one-for-one displacement of primary plastic production
2. Most plastic can only be recycled once or twice … so, recycling only delays — rather than prevents — disposal in landfill or incineration,
and 3. Whilst recycling has clear environmental benefits, it’s not always the most economically-favourable choice
- https://www2.mst.dk/Udgiv/publications/2018/02/978-87-93614-73-4.pdf [Life cycle assessment of grocery carrier bags]
This report is specifically for plastic carrier bags in Denmark.
For plastic bags, re-using the bag as many times as possible, re-using the bag as a bin liner, and incineration (in that order), might be the most environmentally friendly ways to make use of a plastic bag, and eventually dispose of it (outlined on page 16 of the report).
The report takes into account these environmental measures – climate change, ozone depletion, human toxicity cancer and non-cancer effects, photochemical ozone formation, ionizing radiation, particulate matter, terrestrial acidification, terrestrial eutrophication, marine eutrophication, freshwater eutrophication, ecosystem toxicity, resource depletion, fossil and abiotic, and depletion of water resource.
The report lists some it’s limitations on page 24 – “This study does not include the assessment of other types of carriers, such as personal bags or bags provided by other retailers. The report does not consider behavioural changes or consequences of introducing further economic measures. The study does not take into account economic consequences for retailers and carrier bag producers. The environmental assessment does not take into account the effects of littering.”
So, economic measures and other issues like littering aren’t taken into account in this report.
Separate to the two reports, when talking specifically about incineration and impact on the environment or people:
Some technology may remove harmful ash and pollutants from emissions, but may leave in CO2 (thisiseco.co.uk)
The IBA (Incinerator Bottom Ash) and other waste by products of incineration can be recycled and re-used for applications like construction, and bulk fill (thisiseco.co.uk), or road sub layers (printwaste.co.uk)
Some incinerator waste is hazardous, and this needs separate treatment (printwaste.co.uk)
Economic Considerations When Disposing Of Plastic
Obviously, going zero waste (or minimising waste) or re-using plastic items and materials where possible are going to cut down on waste management costs for any given society.
For the main waste management options, there’s probably two considerations for economics:
Cost & Profitability
How expensive each waste management option is depends on the city and local conditions. Some figures indicate recycling is cheapest per ton, followed by landfill, and then incineration. But, costs per ton in each location can vary, and can also change over time because of different variables and factors and conditions
So, recycling can be economically viable in some ways, but not so much in others.
Incineration can be expensive in terms of capital and raw costs, but, there needs to be some consideration that plastic tends to provide good/dense energy when burnt (because it is generally made with fossil fuels) – so, waste for energy incineration may be more economically viable than letting plastic that can’t be recycled sit in landfill in some instances (just as one example).
Also, consider these comments by Ourworldindata.org in relation to recycling plastic:
“Recycling processes can often lead to products of lower quality and economic value — often termed ‘downcycling’”
“… whilst recycling has clear environmental benefits, it’s not always the most economically-favourable choice. The relative profitability between recycling and the production of new plastic is strongly determined by oil prices. When oil prices are low, it can be cheaper to make raw plastics than to recycle”
Potential Human Health Impact Of Disposing Of Plastic In Different Ways
There isn’t as much clear information on the human health impact of each disposal method.
But, some potential ways some disposal methods could impact human health directly or indirectly might be:
If flues, dioxin capture, and other air pollutant or air emission devices aren’t set up or installed on incinerators, air pollution could impact human health from incineration
Plastic such as PVC in landfills without adequate leachate management and landfill liners could contaminate soil and water sources that humans come into contact with.
Plastic that leaks from landfills could also break down into smaller plastic particles that humans ingest or inhale (through water or food supplies) – and the impact of micro plastics on human long term is uncertain at this stage.
These are more subjective and speculative effects though.
Practical Considerations For Disposing Of Plastic
Different plastic types (LDPE vs PVC for example) may have different ideal scenarios for waste management
Different plastic items (plastic bags vs straws vs pipes vs containers vs bottles, and so on) may have different ideal scenarios for waste management
Different countries (high vs low to middle income countries) and cities (major vs smaller cities) will have different levels of waste management systems and technology in place.
Some countries have no waste management, or have open and uncontained waste dumping sites – which obviously changes things
Only a limited number of plastics can be recycled, and some plastics are rejected from recycling facilities for different reasons (where they are sent to landfill or incineration)
Waste to energy is only one form of burning plastic – gasification and pyrolysis are examples of others. Further pros and cons of burning plastic can be found at https://www.nationalgeographic.com/environment/2019/03/should-we-burn-plastic-waste/
There’s a big difference between well contained and managed landfill sites, and uncontained landfill sites that leak or have an inadequate liner and leachate management system.
The same can be said for incineration and recycling facilities that are very advanced, and those that aren’t
Each waste management option may have different pros and cons, and so, there may be a way to utilise each option for different types of plastics and plastic items (without excluding one of them altogether)
Other Resources On Disposing Of Plastic, & Other Types Of Waste