Life Cycle Assessment of Carrier Bag Reuse – Which is Best?

The big question about Life Cycle Assessment of carrier bag reuse is which is best, plastic or brown paper/ card? There is also the question of is it best for the environment to be re-using an ordinary supermarket bag, of a heavier-weight bag which is sold for reuse?

Life Cycle Assessment of Grocery Carrier Bags by the Danish Government

An independent Lifetime Cost Assessment (LCA) of grocery carrier bags materials has shown that plastics prove to be the material with the overall lowest impact on the environment.

On March 14th, 2018 the danish environmental protection agency (miljøstyrelsen) published a study that analyses the life cycle environmental impacts of production, use, and disposal of grocery carrier bags currently available in Danish supermarkets.

Read the report; “Life Cycle Assessment (LCA) of grocery carrier bags“. LCA confirms the low carbon footprint of total carbon when a balance is completed. European bioplastics recommend using a Life cycle Assessment as the basis for policy formulation.

Life Cycle Assessment of Supermarket Carrier Bags

A study from the united kingdom entitled the “life cycle assessment of supermarket carrier bags” is casting doubt on the supposed environmental benefits of reusable shopping bags. A study from the united kingdom entitled the “life cycle assessment of supermarket carrier bags” is casting doubt on the supposed environmental benefits of reusable shopping bags.

Recycling is available at selected supermarkets. Some stores also offer a financial incentive if carrier bags are reused. Buy a ‘bag for life’ – they last longer – when this bag reaches the end of its life the store will replace the bag and the old one can be recycled.

Last year the British environmental agency published findings in the ‘life cycle assessment of supermarket carrier bags’ that showed that ‘bags for life’ have to be used a number of times before they can be considered a better environmental option than plastic carrier bags.

The U. K. Environment agency did a life cycle assessment comparing the environmental impacts of conventional plastic grocery bags (high-density polyethylene (HDPE)) with a number of other supermarkets carry bags including paper, longer-life bags (cotton, non-woven polypropylene), plastic bags-for-life (low-density polyethylene), and a starch polyester blend bag.

Life cycle assessment LCA of grocery carrier bags

In 2011 Britain's environment agency published a Life Cycle Assessment of Carrier Bags, which concluded that long-life bags have to be reused a number of times – more than 100 times in the case of a cotton bag – if they are to be environmentally a better option than standard plastic carrier bags.

The UK's environment agency had also published an earlier-drafted life cycle assessment of supermarket carrier bags. The aim: was to establish both the environmental impact of different carrier bags that are in use and their reuse practice.

Last year Britain's environment agency published a life cycle assessment of supermarket carrier bags, which concluded that long-life bags have to be reused a number of times if they are to be environmentally a better option than standard plastic carrier bags.

Original article as published on Feb 28, 2011:

Report on Life Cycle Assessment of Supermarket Carrier Bags Answers the Question of Which is Best

With Italy following a number of other nations which have banned their shops from providing free single-use plastic bags, the issue is an important one. The question of exactly what benefits do flow from all the personal hassles of always remembering to take a reusable bag when visiting the shops needs a clear answer.

The UK Environment Agency has now issued (22 February 2011) a report which answers a few of these questions on the lips of Life Cycle Assessment of Carrier Bag of interest to shoppers, and their report is available on their website for downloading.

The report provides advice for retailers and shoppers on the carbon footprint of a range of different multiple-use carrier bags commonly offered for sale at check-outs. In particular, it asks the very pertinent question of how many re-uses of these “bags for life” are necessary before their environmental impact becomes less than for a single-use bag which you throw in the bin as soon as you get home.

The most interesting conclusions of the study were that:

1. Whatever kind of bag is utilized, the key to reducing the impact is to take it back and refill the same bag as many times as practicable whether for shopping, lining the kitchen bin, or other purposes in the home, garden, or office.

2. The plastic ‘bag for life' favoured by many ( low-density polyethylene ) only needs to be used 4 times to be certain that it has got a lower carbon emissions footprint than single-use, lightweight ( high-density polyethylene ) carrier bags.

An Environment Agency speaker asserted that: “A heavy part of the environmental impact of these bags is linked with the resources employed in their production. All multi-use bags must be reused as much as is possible to rein in their relative environmental impact and also need to be responsibly recycled at the end of their life.”

“Plastic “bags for life” only really need to be used a few times to have a lower environmental impact than single-use carrier bags.”

Lightweight single-use carrier bags have the lowest carbon footprint per bag when you consider them primarily for their resource use and production. Paper, heavyweight plastic and cotton bags all use more resources and energy in their production.

Lightweight single-use carrier bags aren’t hugely negative, especially if you re-use them once or twice. It all comes back to how many times a bag is reused.

Are Those Plastic ‘Bags for Life’ Offered in Supermarkets Best for the Environment?

The popular plastic ‘bags for life’ (low-density polyethylene), now routinely for sale at most supermarkets, do need to be used four or more times to ensure they have a lower carbon footprint than lightweight (free) bags used only once.

Premium, heavier weight ‘bags for life’ that are made from materials that look like fabric and are made from woven plastic need more re-use.

They need to be re-used 11 times before they will have a lower carbon impact than single-use bags.

Useful though this is, for the environmentally aware shopper, it clearly still leaves many unquantifiable issues in connection with the use of shopping bags unanswered. The Environment Agency itself acknowledges that other environmental impacts of single-use lightweight plastic bags such as litter weren’t assessed by the study.

These are important, and also need to be taken into account. That is more difficult and much more subjective. That's where te advice from a life cycle assessment consultant may be needed.

The Scandal of Ocean Plastic Waste

There is in addition another wider problem with the use of plastics which oceanographers are becoming increasingly concerned about, and which needs scientific study. It is one of the billions of bits of plastic floating in the seas of the globe, which continues to build-up.

The worry is that fish are unavoidably ingesting huge quantities of tiny bits of plastic, and nobody knows what effects that will have on marine life over the coming years.