Updated

Though it might be convenient to just rinse these five common household items with water and flush them down the drain, trust us, it’s worth it to throw them in the trash instead.

Eggshells

You might think that a crushed up eggshell will go down the drain smoothly, but it actually is causing blockage. The sharp, hard edges of the shell will collect other things coming down your drain and eventually cause a clog. These are the 25 things your plumber won’t tell you.

Grease

When you pour grease down the drain it sticks to the inside of your pipes and the pipes in the street. This can cause the entire pipe to become clogged over time. Other oil-based products are also dangerous to pour down your drain, such as cooking oil, salad dressings, butter, mayonnaise, and fat. If needed, make sure to let the grease cool first, then dispose of it in the trash instead.

Flour

Flour coagulates when mixed with water. This can clog your pipes by coating the edges and catching other bits of disposables trying to make their way down. Always throw your flour, whether mixed with water or not, in the garbage. These are the items you should never put in your dishwasher.

Medication

If you flush your unused or expired medication or crush it up and pour it down the drain, those chemicals will be leaked back into your drinking water and the environment. Always make sure to dispose of unwanted medication at your local pharmacy or police department, which will have access to medical waste disposal units.

Produce stickers

Many times people wash their fruit and forget to take the sticker off; it falls in the sink and you eventually just let it go down the drain. Peel them off before you wash your fruit and dispose of it properly. Those little stickers don’t dissolve in water and can clog your pipes and block screens and filters or pumps at the water treatment plant

This story was originally published by Reader’s Digest. Read more things you should never, ever pour down the drain here.