When flexible plastic entered the consumer packaging market in the 1950s, it proved a game-changer for the industry.
The new lightweight and versatile material grew in popularity in the decades that followed, and paper carrier bags in particular – once the grocery bag of choice – were slowly phased out as plastic carrier bags took over.
Lighter, stronger and more versatile than their paper predecessors, plastic bags offered a cheaper, more durable and more convenient solution – one designed to be used over and over again.
But over the decades that followed, with more and more people choosing to throw bags away rather than reuse them, plastic pollution has become an increasing problem.
Today, for many, plastic bags are packaging’s public enemy number one. Demand for paper bags has begun to rise once more, with Morissons and Woolworths among retailers to reintroduce paper bags in a bid to reduce plastic waste.
But which are actually better for the environment – plastic bags or paper bags?
Packaging Knowledge compares the two types of bags, from the beginning of their life-cycle to the end.
Plastic bags vs paper bags – Production
Plastic bags are largely derived from crude oil – a fossil fuel. Whilst a single plastic bag only takes a small amount of oil to make, this oil cannot be replaced, so regular plastic bags are neither renewable or sustainable.
Paper is manufactured from trees – a renewable source. However, making paper bags in large volumes requires a lot of trees to be chopped down. This is one of the main reasons why plastic bags were invented in the first place – to reduce the impact on forests around the world.
You can check if paper is from a responsibly-managed forest through certification by the Forest Stewardship Council, but global deforestation is still a problem.
Another downside of paper is that it takes a lot of water to produce, so a paper bag uses up more water than a plastic bag.
Both paper and plastic bags use energy to produce, which releases carbon dioxide into the atmosphere which pollutes the environment.
However, making a plastic bag uses around a quarter of the energy used to produce an equivalent paper bag, which means a much lower carbon footprint when it comes to production.
Plastic bags vs paper bags – Transportation
Plastic is lighter and thinner than paper, so you can transport more plastic bags, at a lower cost, than you can paper bags of an equivalent size.
As paper bags take more journeys – or heavier journeys – to transport, this means they also have a higher carbon footprint when it comes to transportation.
When you take production and transportation energy use into account, a paper bag needs to be used three times for it to be as environmentally-friendly as a plastic bag used just once. But as we know – a plastic bag can and should be used more than once.
Plastic bags vs paper bags – Cost
Plastic is the cheapest to produce of all common packaging materials – another reason why it has become so popular.
Plastic bags cost less to produce than paper, largely due to the less intensive production method and the fact that they require less energy to produce. As noted above, they also cost more less money to transport than paper bags
With global energy prices and fuel prices currently at or near an all-time high, production and transportation costs for paper bags are higher than ever, when compared to plastic bags.
Plastic bags vs paper bags – Reusability
Plastic is stronger, lighter, and more durable than paper. It is also largely waterproof, whereas paper is susceptible to water damage, which can drastically reduce its strength.
The superior strength and flexibility of plastic bags make them more versatile and more durable than paper bags, making them more suitable for reuse.
For the creator of the first plastic bag, Sten Gustaf Thulin, this reusability was the main driver behind his invention. He always carried a bag folded-up in his pocket, so that he could use it over and over again.
Thulin’s invention was “very much an improvement on what there was before,” his son, Raoul Thulin, told the BBC in 2019.
“What we’re all being encouraged to do today – to take your own bags to the shop – he was doing back in the 70s and 80s just naturally because, well, why wouldn’t you?
“To my dad, the idea that people would simply throw these away would be bizarre.”
Plastic bags vs paper bags – Litter impact
But throw them away people have. Whether down to convenience, laziness or a combination of the two, the plastic bag became a throwaway item.
The bag designed to be used over and over again became, for many, a single-use bag. Carrier bag taxes imposed by various governments have discouraged use – with more people taking their own bags to the shops – but it is beyond doubt that carrier bags, incorrectly disposed of, have contributed to the plastic pollution problem we face today.
When it escapes refuse streams and reaches the open environment, a plastic bag’s durability becomes a negative factor. Plastics can take anything from 10 years to hundreds of years to decompose. Most plastic bags are at the lower end of that scale, but this is still potentially a long time for them to pollute their surroundings and, as they break down, leave behind dangerous microplastics.
Paper bags, on the other hand, will benefit from their reduced durability. Most types of paper are biodegradable, i.e. they can be broken down by bacteria or other living organisms. Most plain paper bags – i.e. without a laminate coating or similar – will break down in the open environment in a matter of weeks.
So if a paper bag and a plastic bag were both to escape refuse streams and end up in the open environment, it’s fairly clear which has the greater negative impact on its surroundings.
Plastic bags vs paper bags – Recyclability
Plastic bags are recyclable, albeit not as widely recyclable as rigid plastics, such as plastic bottles. Most local authorities don’t collect plastic bags and other flexible plastic in their kerbside recycling, so you may need to take yours to a plastic bag recycling point, which are available at most large supermarkets.
On the other hand, paper is the most widely recycled material in the UK. Most local authorities collect paper in their kerbside collections. Some paper bags, such as those with a glossy or laminate coating, may not be suitable for recycling, but regular plain paper bags should be suitable for recycling with other paper and cardboard waste.
So although plastic bags and paper bags are both recyclable, the latter is more easy and convenient to recycle for the vast majority of people, which in part explains why recycling rates are much higher for paper than for flexible plastic.
So should I use plastic bags or paper bags?
If you want to do the right thing for the environment, the best thing to do is to use a bag that you already own. Both paper bags and plastic bags use resources to produce. This means they both have a carbon footprint, so the best solution is to not add to the demand for more to be produced.
Use a bag you already own, over and over again. When it can’t be used any more, try to repair it. If it can’t be repaired, recycle it.
If you need to buy a new bag, then plastic and paper bags both have their pros and cons. These are summarised below, so your decision might come down to which aspect of a bag’s properties you care most about.
People often focus only on the end of a bag’s life-cycle, at which stage plastic’s durability becomes a negative factor, when compared to that of paper.
We’ve all seen pictures and videos of plastic pollution, which is undoubtedly a big problem but, for consumers trying to do the right thing for the environment, it only tells part of the story.
To take a holistic view of the environmental impact of plastic bags versus paper bags, we must look at the full life-cycle analysis of each bag, including the impact of production and transportation.
Paper bags take more energy and more water to produce than plastic bags. They are also thicker and heavier, so there is a greater environmental impact in transporting them to the shops.
When you take all of these things into account, the plastic bag is more eco-friendly, as a paper bag must be used at least three times for it to be better for the environment than a plastic bag used just once before being recycled.
And who uses a plastic bag just once these days?
Plastic bags – pros and cons
- Pros: Strong, lightweight, durable, versatile, cheap, efficient to make (use very little oil and energy), lower carbon footprint (production and transportation), highly reusable, recyclable (collection points only)
- Cons: Made from fossil fuels, not renewable or sustainable, not widely recyclable via kerbside collections, can pollute the environment for years in the event of littering
Paper bags – pros and cons
- Pros: Made from a renewable source, reusable, widely recyclable, biodegrades in the open environment in the event of littering
- Cons: Heavier, less durable, susceptible to water/moisture damage, less efficient to make (uses lots of energy and water), higher carbon footprint (production and transportation), can contribute to global deforestation (if not from responsible source)
