Research reveals that melamine sponges, commonly used for cleaning, release more than a trillion microplastic fibers globally each month due to wear and tear. These fibers can contaminate water systems and enter the food chain.
Melamine sponges release trillions of microplastic fibers every month, posing environmental risks. Recommended solutions include making denser sponges and using alternative cleaning methods.
If you have white shoes or have tried to clean crayon marks off the wall, you’re probably grateful for melamine sponges. Known for their ability to remove stubborn stains and abrasions without the need for additional cleaning agents, these sponges rely on their distinctive abrasive properties. However, these “magic” sponges shed microplastic fibers as they wear out. According to a study published in the journal ACS Environmental science and technologyIt is estimated that melamine sponges contribute to the release of more than a trillion microplastic fibers globally each month.
Melamine foam is composed of a poly(melamine-formaldehyde) polymer – a network of tough plastic strands gathered into a soft, lightweight foam that is surprisingly abrasive, making it an ideal material for highly scratchy sponges. But as the sponge wears out after use, the foam breaks down into smaller pieces that can release microplastic fibers that seep into sewer systems. Once released into the environment, the fiber can be consumed by wildlife and make its way into the food chain. Yu Su, Baoshan Xing, Rong Ji and colleagues wanted to see how the density of a melamine sponge and the roughness of the surface it rubs affect how quickly the foam degrades, as well as to count how many microplastic fibers the sponge sheds.
Research results on microplastic emissions
The team purchased several sponges from three well-known brands, then repeatedly rubbed them against the metal surfaces, causing the foam to wear away. They found that sponges made with denser foam erode more slowly and produced fewer plastic microfibers than less dense sponges. Next, the team determined that a single sponge releases approximately 6.5 million fibers per gram of worn-out sponge, and they assumed that all sponges sold, on average, wear out by 10%. To get a rough idea of how many fibers could be released per month, they looked at Amazon’s monthly sales for August 2023. Assuming those numbers remain constant, the team calculated that 1.55 trillion fibers could be released from melamine sponges each month. However, this number only takes into account one online retailer, so the actual amount may be higher.
To help reduce the emission of microplastic fibers, researchers recommend that manufacturers create denser, stiffer, and more abrasion-resistant sponges. Additionally, they suggest that consumers choose natural cleaning products that do not use plastics and recommend installing filtration systems to capture shredded plastic microfibers both at home and in wastewater treatment plants.
Reference: “Chemical-mechanical formation of poly(melamine-formaldehyde) plastic microfibers during wear of cleaning sponges” by Yu Su, Chenqi Yang, Songfeng Wang, Huimin Li, Yiyu Wu, Baoshan Xing, and Rong Jie, 6 June 2024, Environmental science and technology.
doi: 10.1021/acs.est.4c00846
The authors acknowledge funding from the National Natural Science Foundation of China and the Key Area Research and Development Program of Guangdong Province.
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