I have been collecting used kitchen sponges from short term apartments for the last 1,5 years. It is a pity that this kind of material ends up in the rubbish. Τhe synthetic materials that they’re composed of continue to release dioxins and formaldehyde into soil and the atmosphere. Every sponge has its unique color from its use by different people that stayed in each apartment. These are the results of few experiments I did during our stay of the lockdown.