Fats, oil and grease (AKA FOG) should never be washed down the drain. A leading cause of plumbing problems, these substances stick to the inside of pipes and when cooled, solidify. "Grease, oils and fats act as a binder for other types of drain waste and can create thick, sticky glops that coat your drain pipes, preventing anything from being able to pass through," plumbing expert, David Cruz at MyJobQuote explains. Despite this, 48% of Brits have admitted to pouring FOG down their drains, according to Lanes Group. Instead, leave them to cool and solidify before placing them in the bin.