Are Compostable Shopping Bags the Best Solution?

Are Compostable Shopping Bags the Best Solution?

When Pick N Pay introduced their new compostable shopping bags on the 3rd of July this year, Social Media exploded with praise for the retail giant.  Even here at EcoPack, requests for bags like this started pouring in.  And it’s great!  People are really excited about getting rid of plastic!

Although any movement away from plastic is good, we do need to ask ourselves whether this is the best solution to our plastic bag problem.  Whether or not we are now completely absolved from our guilt when purchasing bags at the till.

The Pros

Conventional plastic shopping bags are made from fossil fuels.  Fossil fuels are a finite resource, so a big no-no where sustainability is concerned.  Compostable shopping bags on the other hand, are made from vegetable matter like maize and potato starch.  So as far as pre-life benefits go, compostable bags get the golden star.

Another benefit is that they are home compostable (according to Pick N Pay, so let’s assume they truly are) and will break down under the right conditions.

The Cons

There are three possible problems that arise.  Firstly, how many people are actually going to compost the bags?  Sure, some will, but they are probably the minority. Most bags will end up in landfill, guaranteed.  Which leads us to the next problem – landfill.

If you didn’t know, landfills are not designed to break down waste, only store it according to  The lack of oxygen in landfill is the main reason for this. Almost nothing will break down in landfill as archaeologist William L Rathje has found first hand.  After digging deeper into the layers, he has found perfectly preserved hotdogs next to a newspaper dated 1967!

Items that do start to break down, degrade very slowly and the lack of oxygen results in the bacteria producing methane gas – highly flammable and dangerous when collected underground.  Bottom line, compostable bags will not break down in landfill, they will add to the existing waste crisis we are experiencing in the Western Cape.

Another problem to consider, is that they might give people a false sense of security.  Touting them as the solution to our plastic bag problem, can steer ill-informed customers away from the most environmentally friendly solution we have – reusable bags. After all, who wants to lug around reusable shopping bags when you can just get compostable ones at the till?


It’s very important to note that in many cases, biodegradable alternatives to single-use items are the best solutions.  Take restaurants as an example.  Restaurants do need single-use takeaway containers.  In this case, Bagasse (sugar cane) containers serve as the best alternative to polystyrene containers.  It would be unrealistic to think that most patrons will be happy to bring their own containers for leftovers, however ideal that would be.  It’s just the nature of the setting.

And what about food trucks and festivals?  Again, in this case, biodegradable packaging is probably the best solution.

So to be clear, there is a place for compostable and biodegradable single-use items.

When it comes to shopping bags, the setting is very different.  Purchasing your own reusable shopping bags and taking them with, is a realistic solution.  In this case, reusable bags would be the best solution.

But do compostable shopping bags beat plastic bags?  By a land(fill)slide!