German health agency warns that kitchen sponges hide harmful bacteria

The Federal Institute for Risk Assessment (BfR) says that the appearance or smell of kitchen sponges is an unreliable indicator of safety. Laboratory tests showed that sponges contaminated with Escherichia coli and Salmonella looked clean and did not feel greasy, yet they carried high bacterial loads.

Even light pressure when wiping can transfer these pathogens to surfaces. Contamination can occur during the preparation of raw chicken, providing food residues that feed bacterial growth. The BfR recommends replacing sponges more often for households with sick, young, or elderly members, and always after cleaning surfaces that have touched raw meat.

To reduce bacterial load, sponges can be boiled for at least two minutes at temperatures above 70 °C or washed in a dishwasher on programs of at least 60 °C. Alternatives such as microfiber cloths or using sponges less prone to bacterial growth, like scrub brushes, are also suggested.