Riesci a indovinare cosa c’è questo strato duro sul fondo del vecchio lavello della cucina in metallo e come è successo? L’ho trovato dopo essermi trasferito nell’appartamento. L’ho sfregato dolcemente con asciugamano di carta secca e nulla di visibile si aggrappava al tovagliolo di carta. Potrebbe essere uno stampo come quelli verdi? È una preoccupazione per la salute?

The residue under the sink appears to be water damage, mold, or mineral buildup from a leak. The discoloration and potential dampness suggest that water has been seeping from the sink drain or connections over time. The yellowish and dark spots could indicate mold or mildew growth due to prolonged moisture exposure.

Possible Causes:
1. Leaky Drain Connection – The seal between the sink and the drainpipe might be loose or deteriorated.
2. Condensation Buildup – If the area is humid, condensation from pipes might be collecting and causing staining.
3. Previous Water Leak – The stain could be from an old leak that has since dried up.
4. Mold Growth – If there’s an ongoing moisture issue, mold can develop on the underside of the sink and surrounding areas.

What to Do:
• Check for Active Leaks – Run water in the sink and inspect the drain connections for drips.
• Clean the Residue – Use a mixture of vinegar and baking soda or a mold remover if mold is present.
• Replace Seals or Pipes if Needed – If leaks are found, tighten fittings or replace damaged parts.
• Improve Ventilation – Ensure there’s proper airflow to reduce humidity under the sink.

It’s insulation, it can be asbestos. Just leave it be.