Why pouring used oil down the drain can hit your wallet - and how to avoid it

We all took time learning to sort our garbage correctly. As the rules aren't always intuitive, many of us had to rely on guidelines provided by waste management authorities. If you've gone through these instructions, you might have noticed guidance on how to dispose of used oil. Unfortunately, this substance is often mishandled, leading to considerable damage.

We most likely know which bin to use for plastics, glass, or dirty paper. But what about used cooking oil? Because it is a liquid, some might instinctively think to pour it down the toilet or sink. However, these are mistaken approaches!

Before discussing how to get rid of used oil properly, let's understand what happens when we pour it down the toilet. One thing we need to clarify is that oil only remains liquid or semi-liquid for a while. When poured down pipes (potentially damaging their plastic parts if the oil is still hot), it combines with food scraps, eventually forming a hardened “plug” blocking the pipe. This obstruction isn't easy to remove and usually requires professional help.

If the sink or toilet isn't the right place to dispose of used oil, then where should it go? Regulations recommend placing it in mixed waste. This is straightforward if we're dealing with a small amount of oil—we can wipe it up with a kitchen towel. But what should be done with more substantial amounts of used oil?

For larger quantities, the guidelines suggest two possible solutions. First, pour the oil into a bottle, seal it, and dispose of it in the mixed waste bin. The second solution is for more significant amounts of used grease, which should be collected in a container and brought to a Municipal Selective Waste Collection Point.