In this guide, we compare the different materials of bag – plastic, paper, cotton, composite, and different reusable bags.
We look at which ones might be best environmentally, practically, and from an overall perspective.
Summary – Which Type Of Bag Material Is Best?
Which Bag Is Best Environmentally?
We’ve referenced a few popular lifecycle assessment reports in this guide.
We’ve linked to these reports and summarised important information from those reports at the bottom of this guide.
We also referenced some other sources that provide more feedback on different bag materials and bag types at the bottom of this guide.
As a summary of what we found, along with some additional information and considerations about practicality of different bag types and materials…
– Which Bags Are Best
Single use LDPE plastic bags might be some of the most eco friendly across several environmental measurables/categories according to some life cycle assessment reports.
And, when it comes to human toxicity impact, paper and composite bags can be equally as low impact
Re-using bags as many times as possible, repurposing bags for as long as possible, and trying to limit the amount of new bags you buy can be beneficial from an environmental perspective.
Unbleached bags and bag without printing on them (i.e. plain looking bags) can also be more environmentally friendly.
– Re-Using Bags
Organic cotton and cotton bags have to be re-used far more times than the more disposable bags (like plastic) in order to have the same environmental performance, largely because of their significant production footprint in terms of energy, resources etc. (which takes more uses to average out … soft plastic can be cheap and have a low production footprint).
Organic cotton has to be used 20,000 times, and conventional cotton, 7100 times
Composite (jute, PP and cotton) might be a better reusable option than cotton bags, only having to be used 870 times to match the baseline LDPE plastic bag’s impact
– Bags Will Reach A Point Where They Can No Longer Be Re-Used
Bags will reach a point where they can’t be re-used or repurposed, and deciding on what to do with them at this point is important.
We may have to choose between landfill, incineration or some other form of waste management
Recycling and incineration appear to be desirable disposal options for some types of bag materials when a bag can’t be used anymore
From bankrate.com: [Considering what to do with bags after they can no longer be used or re-used is an important question]
– The LCA Report Used May Have Limitations
These LCA (life cycle assessment) report used though doesn’t account for several factors such as the impact of littered and polluted waste in the environment, or economic impact, just as a few examples.
Also, the main LCA we reference is purely a Danish study – so things like bag types, recycling rates, waste management systems, bag production processes, and so on, can vary country to country, and impact results.
A full picture of the full impact of each type of bag may not fully available yet, and might be considered location and situation specific.
– Determining The Best Bag Depends On The Indicator Being Measured
The best bag can certainly depend on the indicator you are measuring or assessing for
Some examples of indicators include amount of greenhouse gas emissions, water use and consumption, waste generated, litter rate, pollution and mismanaged waste rate, time taken to break down and decompose, impact on humans, impact on wild life, and so on.
Practical Considerations For Each Type Of Bag
– Paper Bags
Paper bags may have issues with strength, durability and getting wet and losing their integrity (if they get punctured, torn, or stretched)
– Soft Plastic Bags
Soft plastic bags may have strength issues with heavy loads
– Composite & Natural Fibre Bags
Composite and natural fibre bags can be extremely strong and can provide the best strength and durability of all the bags – jute composite bags in particular can be extremely strong and durable.
– Reusable Bags
Reusable bags like cotton and composite might be more expensive to buy and manufacture than the extremely cheap disposable plastic bags, but they often last far longer.
The Type Of Bag We Use Is Only One Sustainability Lifestyle Choice
Apart from the choice of bag we use, we have other significant lifestyle choices we can make if we want to be more sustainable, such as the food we eat, how we get around in transport, and the home we live in (just as a few examples).
So, sustainability can be something we address on a wider scale than just our bag choice.
qz.com makes discusses this:
As the Verge [Verge article listed in the resources below] pointed out last year, regardless of the bag you choose, what is likely of vastly greater importance is what you choose to put in it and how you carry it around: Eating less meat, cycling or walking to the store, and buying locally-made grocery products are all likely to make a bigger difference in lowering your personal contribution to environmental problems.
The simplest advice for individuals seems to be this: Whatever you have in your house now—be it a pile of cotton totes, or a jumble of plastic bags—don’t throw them out. Keep using them until they fall apart.
Whatever the material, use it as a garbage bag once you can’t use it for other purposes any more. And whatever you do, try not to buy new ones.
Find new uses for old clothes, use textiles until they wear out, and when you want something new, buy vintage.
bankrate.com also discusses this:
[More important eco lifestyle choices than the types of bags we use might be what we drive, what we eat, and how big our house is an how well insulated it is]
Types Of Plastic Bags
Plastic bags can come in different types.
There’s the common lightweight LDPE plastic shopping bags, and also the heavy plastic bags, such as PP, PET and polyester.
There’s also other micellaneous types of plastic bags.
Environmental Impact Of Each Type Of Plastic Bag, & How Re-Use Impacts Environmental Impact
According to the above LCA report (available in the mst.dk resource link below):
Plastic LDPE bags have the overall lowest environmental impact across a range of environmental measurables
Biopolymer bags providing a similar impact to plastic LDPE bags across climate change, and water resource depletion indicators
Heavy plastic bags like PP, PET, and polyester need to be reused more times to lower their environmental production cost
Woven PP bags have a lower environmental impact than non woven
Best Disposal Method For Each Type Of Plastic Bag
The best disposal method for each bag might be:
Plastic, LDPE – Reusing/repurposing as a bin bag
Plastic, PP – Recycle, reuse as waste bin bag if possible, else incinerate
Plastic, Recycled PET – Recycle, reuse as waste bin bag if possible, else incinerate
Plastic, Polyester PET – Reuse as waste bin bag if possible, else incinerate
Bio Polymer – Reuse as waste bin bag if possible, else incinerate
… Incineration might be the best disposal option for all bags when reuse or repurposing isn’t possible anymore.
Litter & Pollution Rates Of Plastic Bags
In terms of litter and bag pollution rates:
Plastic bags are among the most littered items across society, and some of the most common waste on beaches and in the ocean
This may suggest not only that we use a lot of them, but they have high waste rates and pollution or littering rates
More Information On Plastic As A Material
Read about some of the more general pros and cons of plastic as a material when used in products in this guide.
Types Of Paper Bags
Paper bags can come in a variety of types, made with both recycled and and virgin paper, bleached and unbleached, different colors, and so on.
Environmental Impact Of Each Type Of Paper Bag, & How Re-Use Impacts Environmental Impact
According the the mst.dk LCA report:
Unbleached paper bags may have a similar environmental impact to LDPE plastic bags for climate change, human toxicity (cancer effects), and fossil fuel resource depletion indicators
Unbleached paper has a lower eco impact than bleached paper)
Bleached paper bags need to be reused more times to lower their environmental production cost
Paper bags have to be re-used far less than cotton or composite bags to have the same environmental impact as LDPE bags
Best Disposal Method For Paper Bags
According the the mst.dk LCA report: The best disposal method for paper bags might be ‘Reuse as waste bin bag if possible, else incinerate
More Information On Paper vs Plastic As General Materials
Cotton (& Canvas & Cloth) Bags
Types Of Cotton Bags
Cotton bags can come in conventional cotton, and organic cotton.
Organic cotton is usually made without the use of GMOs or synthetic chemicals like pesticides, and certified organic cotton can have additional standards.
Environmental Impact Of Each Type Of Cotton Bag, & How Re-Use Impacts Environmental Impact
According the the mst.dk LCA report:
Conventional cotton bags have a lower environmental impact than organic cotton
Textile bags need to be reused more times to lower their environmental production cost
Cotton bags have to be re-used the most of any bag type in order to have the same environmental impact as LDPE bags
Best Disposal Method For Cotton & Textile Bags
The best disposal method for cotton and textile bags might be ‘Reuse as waste bin bag if possible, else incinerate’
More Information On Cotton & Organic Cotton As Fibres In General
We’ve put several guides together on the general sustainability of, and differences between cotton and organic cotton:
Composite & Other Reusable Bags
Other Types Of Composite & Re-usuable Bags
Other reusable bags come in many types, with a composite bag made of jute and other materials being one example.
Environmental Impact Of Composite Bags, & How Re-Use Impacts Environmental Impact
According the the mst.dk LCA report:
Composite bags have a similar impact as LDPE bags for the human toxicity (non cancer effects) indicator
Composite bags have to be re-used less than cotton bags to have the same environmental performance as LDPE bags
Best Disposal Method For Composite Bags
The best disposal method for composite bags (like jute composites) might be ‘Reuse as waste bin bag if possible, else incinerate’
More Information On Jute As A Fibre In General
Lifecycle Assessments On Different Bag Types & Materials
This is a Danish lifecycle assessment on different materials of grocery carrier bags.
The key methodology and findings summary parts of the assessment report are available on pages 13 to 19.
Some of the key considerations from the assessment/report are (paraphrased or selected by us):
– Types Of Bags Studied
Different types of plastic bags, recycled plastic bags, paper bags, cotton bags, organic cotton bags, composite bags with jute, PP and cotton
[See page 13 for bag types]
– Environmental (& Human Health) Impacts Assessed
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
[See pages 14 and 15 for environmental impacts assessed]
[Characterisation description and unit of measurement for each impact available on page 39 in Table 5 – characterized mainly according to LCIA methods]
– Preferable Disposal Method For Bags
Re-using a bag as many times as possible is usually the best first option, followed by using it as a bin liner.
Recycling can benefit some types of heavy plastic bags.
Otherwise, incineration is usually a good option when re-use is not feasible or possible
[See page 16 for more info]
– Bag That Provides Lowest Environmental Impact
In regards to production and disposal, plastic LDPE bags have the lowest impact across the whole range of environmental and human toxicity indicators.
For specific indicators, such as human toxicity, paper, composite and plastic PP bags can also be lowest impact
[See pages 16 and 17 for more info]
– How Many Times Bags Have To Be Re-Used To Have The Same Impact As Each Other According To The Impacts Assessed
Regular LDPE plastic bags are the benchmark when used as a waste bag.
Recycled LDPE has to be used 2 times and used as a bin bag to match the impact across all indicators, recycled PET 84 times and recycled, unbleached paper 43 times and re-used as waste bag or incinerated, conventional cotton 7100 times and re-used as waste bag or incinerated, organic cotton 20000 times and re-used as waste bag or incinerated, and composite bags 870 times and re-used as waste bag or incinerated
[See pages 16, 17 and 18 for more info]
– Potential Limitations Of The Study
The results are specific to Denmark (so, the results may be different in some ways in other countries where plastic and other materials is produced, and disposed of differently).
The results may also change if certain assumptions in the report change
From page 24 of the report: “The present study only considers carrier bags available for purchase in Danish supermarkets in 2017. Small very lightweight plastic carrier bags, which are available in Danish supermarkets free of charge as primary packaging for loose food, were excluded from the scope of this study, since they were not included in the 94/62/EC measures. 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.”
Other key factors that might not have been taken into account my include littering of plastic, the breakdown of plastic into micro plastics and nano plastics, different aspects of plastic pollution, the economic feasibility, profitability and other economic tradeoffs of plastic, technological factors, practical factors, human health factors, and other factors.
Other life-cycle assessment studies/reports on plastic bags and other bag types:
UK study measuring global warming impact of plastic bag types (assets.publishing.service.gov.uk)
US study measuring global warming impact of bags (tigerprints.clemson.edu)
What we see from these studies is that there are many variables and factors to consider such as:
– the material the bag is made of
– assumptions made on the size
– weight and consumer behavior associated with the bag
– assumptions made on the material of each bag
– production and disposal of materials and waste in a given country
– whether the bag has bleaching and printing on it
– how many times the bag is re-used
– over what time period the bag is used without buying new bags
– whether the bag is used as a waste liner or not
– transport and delivery of the bags
– and more …
More Relevant Information On Plastic Bags & Their Potential Impact
Cotton & Organic Cotton Bags
[A problem with organic cotton is that if it has lower yields, it will likely have higher resource inputs for the same yield]
[Even accounting for the benefits of organic cotton] conventional cotton came out on top [across many environmental indicators for the bag life cycle assessment]
[The problem with textiles like cotton is there is] very little infrastructure [that] exists for textile recycling
Paper vs Plastic Bags
… replacing plastic bags with paper ones will surely have deleterious side-effects like increasing deforestation.
Making a paper bag also requires more energy and water than making a plastic bag, so for other environmental considerations besides litter, paper products may be worse than plastic ones
Plastic bags come out on the right side of the equation [compared to paper bags] on everything except the recycling side
[When choosing between plastic and paper bags …] Neither option is best. The better option is to bring your own
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