As many of you know, we have been spending a lot of time researching the most environmentally friendly poo bags.
Since starting this journey we've been overwhelmed by the amount of greenwashing and confusion surrounding 'eco-friendly' poo bags.
So we wanted to share what we've learned so far and help set the record straight.
Let's start with compostable poo bags. It's often claimed that compostable poo bags are the best option on the market at present. Indeed, this is what we started out believing and started offering our own compostable poo bags. One of the main purported reasons, besides biodegradability, is that they are 'plant-based'. However, once we started digging deeper, looking at our own poo bags with greater scrutiny and speaking with poo bag manufacturers, we found that this was far from the truth...
So what are they actually made of?
It turns out that all compostable and biodegradable poo bags have to be made with a material called 'PBAT' or Polybutylene Adipate Terephthalate. What isn’t made obvious on packaging or marketing materials is that PBAT is a biodegradable plastic made from fossil-fuels - not plants. This means compostable and biodegradable poo bags are made from the same thing that conventional plastic is made of - crude oil.
Ok, but perhaps PBAT only makes up a small percentage? So perhaps it's fair to describe them as 'plant-based' if the majority of the bag is made from plants? But we were surprised to learn that this isn't the case either.
We've found that PBAT makes up 50-80% of compostable poo bags. Therefore, it is misleading to describe these poo bags as plant-based, when the main ingredient is derived from fossil fuels.
We've now spoken with many of the biggest poo bag manufacturers and try as we might, we still haven't found a manufacturer that can and will them with anything less than 60% PBAT.
So why include PBAT?
All poo bags have to include PBAT for strength and structure. If they were 100% plant-based they would turn to mush very quickly when wet, lack strength and tear easily (some qualities you really don't want in a poo bag!). Indeed, strength is one of the top qualities pet owners state they look for when shopping for poo bags.
This also raises the question of whether 100% plant-based poo bags is something we should be aiming for.
While plant-based plastic may have it's place in a few specific scenarios (e.g. food waste), it raises numerous concerns. For example, the production of plant-based plastic is hugely resource-intensive and requires significant amounts of water, land, energy (using fossil fuels), fertilisers, pesticides and GMOs. Some life cycle analyses (which are the most comprehensive measure of the environmental impact of materials) have shown that it's the same, if not worse, than conventional plastic when it comes to climate change, air pollution and ecotoxicity.
Another concern is that plant-based plastic currently relies on food crops, such as corn-starch and sugarcane. Therefore it directly competes with human food production, potentially driving up costs of food. In fact, The EASAC Report of March 2020 says that “replacing PE (a type of plastic) with a bio-PE (plant-based plastic) would require almost all (93.5%) of global wheat production”. This raises serious ethical questions of growing food to make plastic instead of feeding millions of hungry people. While plastic can be made from non-food plant resources (e.g. algae) this is expensive and isn't widespread yet.
Some experts even believe that plant-based plastic has no role to play in solving the plastic crisis and should instead be focus on reducing and reusing plastic.
The bottom line
If you're surprised by the above - you're not alone, we were too! It is a confusing and complicated topic, made more so by greenwashing.
We understand that, like all sustainability issues, this is a nuanced problem. But we don't believe in obscuring important details or outright lying, as this can prevent genuine progress.
At Pet Impact we know that no product is ever perfect. But we can still strive to make the best decisions possible and be honest and transparent in the process.
Maybe one day, when we have widespread public collection schemes for dog waste to go to industrial composting or anaerobic digestion, compostable poo bags could conceivably have their place. But in reality, we are still a long long way off this.
So what's the answer?
Considering the significant environmental impact of manufacturing compostable poo bags and considering that the majority don't properly biodegrade in home compost (or the open environment) and that most people dispose of them in landfill or incineration... We feel that currently the best option is to make poo bags from waste, i.e. recycled plastic and bio-renewable waste.
We are continually working to improve the sustainability of our products and that's why we are now bringing out a new poo bag, based on what we have learnt. Not only are they made from recycled and waste materials, each bag saves one ocean-bound plastic bottle! Visit our poo bag page to learn more.
References:
https://www.sciencedirect.com/science/article/abs/pii/S0959652620312051?via%3Dihub
https://www.biodeg.org/subjects-of-interest/composting/
https://www.chemeurope.com/en/news/1176729/biodegradable-plastic-particles-in-finished-compost.html
https://plasticsolutionsreview.com/bio-based-plastics/
https://www.frontiersin.org/articles/10.3389/frsus.2022.942724/full#:~:text=The%20results%20show%20that%20the,46%25%20had%20no%20compostable%20certification.
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