Tossing the wrong things down your garbage disposal can cause damage that is both serious and costly. That’s why we’ve compiled five items that you should remember never to throw down your garbage disposal at home.

Bones

It can be tempting to throw bones down the garbage disposal after you finish eating a piece of meat, but this is actually a bad idea. Though you may be able to get away with throwing small bones down the disposal without causing damage, larger bones can harm the machine. Bones also may absorb grease that can clog the drain, so it’s best to just play it safe and throw your bones in the trash.

Coffee Grounds

Most of us have probably washed our leftover coffee grounds down the sink, but this move can actually clump up and clog the drains. That’s why it’s best to throw your coffee grounds in the trash.

Eggshells

Some think that tossing eggshells down the drain can clean the insides of the garbage disposal. However, the thin membrane beneath the shell can get wrapped around the blades, making it so that egg membrane will shoot up and coat your kitchen sink the next time you turn it on.

Fruit Pits

It’s not a good idea to throw fruit pits down your garbage disposal because they are so hard that they will most likely ruin the blades of your disposal. Think of the pit as a piece of wood, because they would both have the same affect on your disposal.

Onion Skins

The fine membrane under the onion’s thick skin is too thin for the garbage disposal to grind it up, so it escapes unharmed and sits in the pipes. Once it is there, the membrane act as a sort of net, catching other food debris and generally just slowing down the process.