Brush your teeth for two minutes, twice a day as recommended, and you’ll spend more than 1,900 hours of your life with a toothbrush in hand. Brushing our teeth is something most of us do on autopilot, but considering the number of toothbrushes we will dispose of in a lifetime, we should probably give a bit more thought to what they are made from.
If you’re diligent about your dental care, and replace your brush every three months as recommended, the average person will get through more than 300 toothbrushes. Plastic, bamboo, electric – billions of all kinds are discarded globally every year. So if you want to make the switch to a more environmentally friendly option, which should you choose?
Academics at Trinity College Dublin and University College London’s Eastman Dental Institute have tried to find the answer. Their study in 2020 compared the four most common options: standard plastic toothbrushes, a plastic toothbrush with a replaceable head, bamboo toothbrushes and electric toothbrushes.
Their “cradle-to-grave” analysis measured the environmental impact of each toothbrush over five years. All aspects of the life cycle were considered, including materials and parts, manufacture, transport, consumer use and disposal.
Impacts measured included climate change, the impact on water quality, human health, land use, resource use and water scarcity. Their findings might surprise you.
The most environmentally sustainable toothbrush was not bamboo, as might be popularly believed, but a continually recycled plastic toothbrush with a replaceable head. This was followed closely by bamboo, according to the study.
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The plastic manual replaceable-head toothbrush and bamboo toothbrush performed better than traditional plastic and electric toothbrushes in every environmental impact outcome measured in the study.
Bamboo isn’t without issue, it should be noted. Growing it may stop land from being put to better use such as increasing biodiversity or growing trees to offset carbon emissions, according to the study. Bamboo however is biodegradable and decomposes naturally which plastic toothbrushes do not.
The environmental impact of the electric toothbrush was 11 times greater than the bamboo toothbrush over its life cycle.
Electric toothbrushes are harmful for the planet and to the people involved in their manufacture and distribution, said lead researcher Dr Brett Duane, associate professor in public dental health at Trinity College.
They are not necessarily better at cleaning your teeth either. Electric and manual toothbrushes are both equally effective at removing plaque from your mouth, says the British National Health System.
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“There is not a lot of evidence to show electric toothbrushes are more effective, unless you struggle to clean your teeth with a normal toothbrush,” said Dr Duane.
The ideal toothbrush is one which uses plastic that’s recycled in a continuous process, said the Trinity researchers. They called for a system where plastic toothbrushes can be collected like batteries and then recycled into new products.
We don’t have that yet, however. Put your old toothbrush in the general waste bin, says MyWaste.ie, the State’s official guide to managing waste. If you want to reduce plastic use, consider swapping to a bamboo or wood toothbrush which can be composted, it advises.
