10 Things You Should Never Put Down Your Drain

As a husband, dad, and the unofficial family handyman, I’ve become quite familiar with the quirks of home maintenance, especially when it comes to plumbing. Through trial, error, and a few calls to the plumber, I’ve made a list of culprits that can wreak havoc on your home’s drainage system.

Some of these might surprise you. Understanding what to keep out of your sink and garbage disposal can save you from headaches, unnecessary expenses, and even help protect our environment.

Here’s my rundown of the top 10 things to never put down your drain.

Milk and Dairy Products

Here’s a one that caught me off guard: milk and dairy products are actually pretty tough on our water systems. Turns out, milk has a high biological oxygen demand, or BOD. This just means it requires a lot of oxygen for bacteria to break it down when it hits the water, which can deplete the oxygen needed by fish and other aquatic life.

So, while a little splash of milk down the drain isn’t a catastrophe, dumping large amounts can cause environmental headaches. Next time you’ve got some expired milk, it’s much better for everyone if it goes into the trash instead of the sink.

Flour

Flour might be a staple in the kitchen, but it’s a menace in your plumbing. Have you ever noticed how flour turns into a paste when you mix it with water? That’s exactly what happens inside your pipes too.

This pasty mess can coat the insides of your plumbing and snag other passing bits, leading to a clog faster than you can say “biscuits.”

Produce Stickers

In the shuffle of prepping meals and cleaning up, those tiny stickers on fruits like apples and bananas often go unnoticed—until they start causing trouble down the drain. Despite their small size, these stickers aren’t water-soluble and can stick to the insides of pipes, teaming up with other debris to form blockages. They can also wreak havoc at water treatment facilities.

To keep things running smoothly, make it a habit to peel and dispose of them in your trash can.

Potato Peels

Any family cookout at our house isn’t complete without a big batch of mashed potatoes, but those potato peels have no place going down the drain. Here’s why: potatoes are rich in starch, and when their peels hit the water in your garbage disposal, they transform into a sticky, glue-like paste.

This gunk is notorious for clogging pipes. In fact, the day after Thanksgiving is famously busy for plumbers, largely thanks to these and other starchy culprits.

Flushable Cat Litter

Despite what the packaging says, “flushable” cat litter and plumbing systems don’t mix well. I’ve learned the hard way that these products can still clump and clog up the works, posing a real headache for your home’s drainage system, especially if you have a septic tank.

Uncooked Rice

As the guy who’s often tasked with kitchen duty, I can tell you that uncooked rice is another stealthy sink saboteur. This little grain might seem harmless, but it has a knack for absorbing water and swelling up to many times its original size, leading to serious blockages.

Grease and Oil

As the go-to guy for fixing things around the house as well as someone who has worked for the city for the last five years, let me tell you about the sneaky troublemakers of the kitchen: grease and oil. These slick substances may glide down your drain with ease, but their journey doesn’t end there.

Grease is especially notorious—it cools, hardens, and forms a gummy trap inside your pipes, capturing other passing debris and causing blockages. While oil doesn’t harden like grease, it still creates a sticky coating inside pipes, increasing the risk of clogs.

Instead of sending them down the drain, keep an old can in your kitchen to collect and solidify these fats. Many communities even offer free grease caps for cans, making disposal a breeze.

Pasta and Rice

I’ve seen my fair share of pasta and rice slip into the sink. But here’s why they’re more than just harmless escapees: both are starch bombs that keep expanding with water exposure.

What starts as a few lost pieces can quickly become a plumber’s nightmare, swelling inside pipes and leading to clogs. Next time, keep an eye on these starchy scraps—your drain will thank you.

Household Fluids

Household fluids like cleaners, paints, and automotive products don’t just flow away harmlessly. These aren’t your ordinary liquid leftovers; they’re potent disruptors of the wastewater treatment process and can even corrode the very infrastructure they travel through. Instead of dumping them down the drain, check for local hazardous waste disposal options.

Coffee Grounds

Tossing out yesterday’s coffee grounds might feel like a no-brainer—straight into the sink, right? Actually, let’s reroute that habit straight to the trash or your compost pile. You might not think much of it, but coffee grounds stick together, building up in your pipes over time.

Think of it as the sediment at the bottom of a river; it doesn’t flush away easily and can lead to some pretty hefty plumber bills if you’re not careful.

Eggshells

Here’s the deal with eggshells—they might seem fragile, but they’re tough on your pipes. You might think that mashing them up in the garbage disposal gets rid of them, but all it does is create a gritty, granular mess.

These bits can catch on other things in your drain, like grease or oil, leading to serious blockages. Better to toss them in your compost bin or trash can; your plumbing will thank you for it.