German health agency warns kitchen sponges can harbor dangerous bacteria

The Federal Institute for Risk Assessment (BfR) in Germany says that a kitchen sponge’s colour or smell does not indicate whether it is safe. Laboratory tests found sponges deliberately inoculated with Escherichia coli and Salmonella showed no visible signs of contamination, yet the pathogens remained viable. Even light pressure can transfer bacteria from a sponge to surfaces, and handling raw chicken can easily load a sponge with harmful microbes. The BfR recommends discarding sponges after cleaning surfaces that have contacted raw meat, or more frequently when vulnerable people such as children, the elderly, or the ill live in the household. To reduce bacterial load without throwing the sponge away, it can be boiled for at least two minutes in water above 70 °C or washed in a dishwasher on programmes of at least 60 °C. Alternatives such as dish‑brushes or microfiber cleaning cloths, which can be laundered at high temperatures, carry a lower risk of bacterial growth.