Scientists at the University of Bath have developed biodegradable microbeads that could replace the plastic ones found in many toothpastes and cosmetics.
Made out of cellulose, the fibre found in wood and other plants, these beads can be quickly broken down by organisms in water treatment plants or the natural environment.
Microbeads are little balls less than half a millimetre in size that are commonly used in toothpastes, scrubs and other cosmetics as exfoliators or for aesthetic appeal. They are too small to be filtered out by water treatment plants and end up in rivers and oceans in large quantities, where they damage ecosystems and potentially enter the human foodchain.
Dr Janet Scott, reader in the department of chemistry at Bath and part of the team that developed the beads, said she hoped they could be used as a direct replacement for plastics.
“[Microbeads] are derived from oil and they take hundreds of years to break down in the environment. We’ve developed a way of making microbeads from cellulose, which is not only from a renewable source, but also biodegrades into harmless sugars,” she said.
Importantly, the team at Bath has developed a technique to continuously manufacture these biodegradable beads in a way that can be scaled up. They do this by forcing a solution of the cellulose through a sieve-like membrane, creating small droplets that solidify into the beads.
Ocean plastic has become a big environmental concern, of which microbeads are just one source. The USA has already banned the sale of cosmetics with microbeads, while a petition in the UK to enact a similar ban reached more than 330,000 signatures. The Ellen MacAthur Foundation predicted that by 2050 there would be more plastic than fish in the oceans unless industry changed the way it used the material.
Separately, more than 600 countries, businesses and civil society groups have made voluntary commitments to improve the health of the ocean, including reducing plastic pollution, at the UN Ocean Conference. Delegates from China, Thailand, Indonesia and the Philippines, some of the world’s worst plastic polluters, have also reportedly promised to work on keeping more plastic out of the sea.
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