A Sustainable Toothbrush: Calculating the Carbon Footprint

The Search for a Sustainable Toothbrush: Which Toothbrush Has the Lowest Carbon Footprint?

By Logan Cohen of Go Green Post

For many of us, brushing our teeth is one of the first things we do in the morning. This means our toothbrush is one of the very first products we interact with. Toothbrushes historically are made of plastic and billions of them are sent to landfills every year. If you’re trying to live a sustainable lifestyle this isn’t exactly the best way to start your day. Luckily, there are better options.

While there are many different impacts of brushing your teeth and toothbrushes, this article will mainly focus on greenhouse gas emissions and climate change. This is because climate change is a massive issue that needs solutions from every possible angle. This is also because many environmental impacts follow a similar pattern to climate change. For example, the creation of air pollutants, eutrophication, and water pollution. The reason for this pattern is that a large portion of the impact of a product results from the energy used in manufacturing.

The Effects of a Carbon Footprint on a Potentially Sustainable Toothbrush

With that said, different toothbrushes will each have a different carbon footprint depending on how they are made, the energy sources involved in manufacturing, the shipping method and distance, and so on.

There are two main options for a toothbrush. You can choose either electric or manual. From there, both options can be made of various materials. In this article, I’ll be comparing plastic to bamboo. Last, both toothbrush options can have replaceable heads. Replaceable head toothbrushes allow you to only replace the head and bristles of the toothbrush when it comes time to get a new one. This cuts down on the impact of the toothbrush because you don’t need an entirely new toothbrush each time you replace your toothbrush.

On the other hand, a regular, non-replaceable head toothbrush requires that you replace the entire toothbrush each time you need a new one, even the handle which is probably still in good condition.

Black and white photo from 1899 showing the use of a toothbrush.
A photo from 1899 showing the use of a toothbrush.
Credit/Source: Dupons Brüssel – “Das Album”, page 62-63

What Is A Life-Cycle Assessment?

Before we jump into the numbers, it’s important to know where they are coming from. Researchers often publish detailed studies known as Life Cycle Assessments or LCAs. An LCA is essential a review of a product or service to determine its various environmental impacts across its lifecycle. A typical LCA will look at the environmental impacts of resource extraction, manufacturing, packaging, shipping, product use, and product disposal.

Environmental impacts vary from study to study but often include climate change, air pollution, freshwater pollution, marine pollution, eutrophication potential, resource extraction, and so on. These studies often compare two products to figure out which has the lowest impact and compare where the life cycle stage impacts come from.

Researchers produce LCAs either out of curiosity, perhaps due to the popularity of a product, or because they are hired by a company to do so. For this reason, it’s not always possible to find LCAs on a specific product. A toothbrush isn’t exactly an “iconic” product in the environmental community, at least not to the caliber of plastic bags, plastic straws, or electric vehicles. They also aren’t something a lot of toothbrush manufacturers are interested in. Accordingly, LCAs on toothbrushes are limited, particularly ones that include a bamboo toothbrush.

However, we can make use of some existing research to figure out part of the question of which toothbrush is most sustainable. I then attempted to fill in the gaps, using my experience as a sustainability professional.

There are two questions we need to answer. First, is bamboo more sustainable than plastic? And second, are electric toothbrushes more sustainable than manual ones?

Let’s start with the second question.

Electric Toothbrush vs Manual Toothbrush

It may seem odd to try and compare the impact of something as simple as a manual toothbrush to its electric counterpart. After all, the manual version is made with far fewer materials and requires far less manufacturing. It also doesn’t require energy to be used.

It should therefore not come as a surprise that an electric toothbrush comes with a significantly higher carbon footprint than a manual one. According to one of the only life cycle studies available, the carbon footprint of a plastic manual toothbrush is about 25.6 kg CO2e over 5 years, while the plastic electric toothbrush is about 47.9 kg CO2e over 5 years (about the lifespan of one electric toothbrush battery. Once the battery is no longer useful, the entire toothbrush must be replaced).

Over 5 years, this means the impact of using a regular plastic toothbrush is about half that of an electric one. But this isn’t the end of the story.

You see, there are two flaws, or rather limitations, to LCAs. One of the flaws is that LCAs don’t show the external impacts of a product. In the case of a toothbrush for example, the LCA does not show that an electric toothbrush has been shown to keep your mouth cleaner than a manual toothbrush, which can result in less need for dental work. In fact, it doesn’t take much additional dental work to make up for the extra impact caused by an electric toothbrush.

How External Factors Can Change the Results

In one study, various dental procedures were quantified in terms of the carbon footprint they generate.

Even a single filling creates about 14.75 kg CO2e. Therefore, if an electric toothbrush helps you to prevent just 2 cavities over 5 years, it will have more than made up for its higher carbon emissions. The real number may even be more like 1 cavity, as you’ll likely need some prep work before the filling can be put in.

Similarly, if you ever need nitrous oxide to help manage pain during a dental procedure, the nitrous oxide alone would contribute to about 119 kg CO2e. With such a large carbon footprint, you would be able to use 3 plastic electric toothbrushes over 5 years to create a similar impact. Therefore, if an electric toothbrush is truly able to help you, it’s more than worth its extra impact.

The second limitation of LCAs has to do with what happens to products once they are disposed of. This also leads us back to question one.

Is Bamboo More Sustainable than Plastic?

The carbon footprint of a regular bamboo toothbrush is only 4.26 kg CO2e. Again, the plastic toothbrush comes in at around 25.6 kg CO2e. In fact, even a plastic toothbrush with replaceable heads comes in at around 5.16 kg CO2e. So, even if you compare a mostly reusable toothbrush made of plastic to that of bamboo that is not mostly reusable, the bamboo option still has a lower carbon footprint.

A bamboo manual toothbrush is better than a plastic one in pretty much every environmental impact category. So, we can confidently say that bamboo products are more sustainable than their plastic counterparts, at least in the case of a toothbrush. But even these impact areas don’t capture the full impact of an item. This is particularly true for plastic.

The other limitation of LCAs is they don’t account for waste in the environment. Yes, they do account for disposal but, this only represents the impact of collecting and treating waste. For example, waste that is landfilled must be collected, shipped, dumped, and managed.

There will also likely be an estimate for emissions generated from the landfill, as well as estimates for leaching, and water pollution. However, I have never once seen an LCA on a product that accounts for the impact of plastic entering oceans, food chains, water supplies, and so on. Plastic in landfills may contribute to microplastics in runoff, but mostly their impact stops being accounted for there. Altogether, this means the true impact of plastic is entirely unknown.

Plastic takes a very long time to break down and when it does, it breaks down into smaller pieces of plastic. These smaller pieces, known as microplastics, can be far more hazardous than larger ones. Not only that, but each fraction of plastic can remain in the environment long enough to cause damage again and again. If you have ever seen pictures from Midway Island, you know exactly what I’m talking about. These pictures show birds dead on an island that is midway across the pacific ocean.

There are no sources of plastic for incredibly long distances, which means the dead birds found all of this plastic elsewhere. Birds can mistake items such as plastic bottle caps for food. They cannot digest plastic, and so they eventually die from eating too much of it. Then, the plastic is available to be eaten by the next bird, who can continue to spread plastic waste around the globe.

A Sustainable Toothbrush: The Sustainable Tomorrow electric bamboo toothbrush
A bamboo electric toothbrush from Sustainable Tomorrow

So Which Toothbrush Should I Use?

As a sustainability professional, I recommend using a toothbrush made with as much bamboo as possible. Further, I recommend using an electric toothbrush, especially if you are someone who struggles to maintain a clean mouth using a manual toothbrush. Personally, I use a bamboo electric toothbrush from Sustainable Tomorrow. They also make a manual option.

The replaceable heads are compostable and the bristles are made with castor seeds so there is no ongoing plastic use. The replaceable heads fit some popular electric toothbrush brands, so you can possibly keep your current electric toothbrush and use it with a bamboo head.

I have an article detailing how to compost indoor compost, including the replaceable heads. You can throw the heads right into an indoor compost bin and take them out to a regular compost pile when the bin needs to be emptied.

You can find all of this and more in our review of the Sustainable Tomorrow bamboo electric toothbrush.