University of Bonn study identifies household items as microplastic sources

Research from the University of Bonn indicates that common household items are significant sources of microplastic exposure. Beyond plastic food containers, everyday kitchen tools such as dish sponges and salt and pepper grinders can release microplastics into the environment and onto cleaned surfaces.

A study published in March 2026 found that all tested dish sponges lost material during use, releasing an estimated 0.68 to 4.21 grams of microplastics per person per year. This occurs because many sponges are made of polyurethane, which wears down due to friction during washing. Researchers utilized a device called ‘SpongeBot’ to simulate real-world washing forces.

Additionally, salt and pepper grinders often utilize polymer components like polyoxymethylene (POM), polypropylene, or polystyrene. Friction from grinding crystals can wear down these plastic parts, creating small particles. To reduce exposure, experts suggest alternatives such as loofahs, plant-fiber cloths, wooden brushes with natural bristles, or cellulose-based sponges.