Hot oil and melted fat seem liquid and harmless when they’re warm, so it’s tempting to wash them down the sink with hot water. But as they cool inside the pipes, they solidify and stick to the inner walls. Over time, this sticky layer catches food particles and other debris, slowly building a stubborn clog.
In your own pipes, that can mean slow drains, bad smells and eventually a full blockage requiring professional help. On a bigger scale, in shared systems or city sewers, fats and oils can contribute to massive solid build-ups that are expensive to remove.
A better habit is to let excess oil cool in a container, then scrape it into the bin, or wipe greasy pans with a paper towel before washing. It’s a small change in routine that keeps your plumbing (and the wider system) much healthier.