Boiling Water, Bacon Grease, and 8 Other Things You Should Never Pour Down Your Kitchen Sink

Things You Should Never Pour Down a Drain

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Things You Should Never Pour Down a Drain
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Do Not Drain!

You might pour certain substances down the drain out of convenience or habit — think draining your pasta or rinsing batter off your hands as you're making fried chicken. But just because these practices are common doesn't mean you should do them. Even if you have a garbage disposal, there are lots of drain no-nos to keep in mind. Here are 10 things you should never pour down your kitchen sink, especially if you want to avoid plumbing problems

Pour some bleach
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1. Bleach and Other Cleaning Products

Not only can pouring bleach down your drain inspire dangerous chemical reactions and release harmful fumes, but it can also damage your pipes. As such, you should avoid pouring any cleaning products down the drain, especially since doing so can lead to water pollution. If you need to dispose of old cleaning products or bleach, avoid the drain and call your local Hazardous Household Waste collection center to find drop-off locations and hours or to see if they offer specific collection days.

Various vegetable and nut oil in bottles on a bright background.

2. Cooking Oil

Even if you dilute cooking oil with hot, soapy water as you rinse it from a pot or pan, the substance can re-solidify in your drain, causing pipe clogs and blockages. To properly dispose of cooking oil, use a funnel to transfer it to a disposable container with a lid. Once it's full, secure the container and throw it away in the garbage. 

Dirty oily pan with cold solid grease saturated fat from bacon after frying macro closeup as unhealthy leftover cleaning job

3. Bacon Grease

Like cooking oil, bacon grease can solidify as it travels down the drain and cause clogs.  Try wiping the leftover grease out of the pan with a paper towel and throwing it in the garbage, use the funnel method mentioned above for cooking oil disposal, or use one of these Redditor tips for reusing bacon grease.

Chef cooking food, Preparation of soup in silver pan on gas, Kitchenware cooking
Prarinya Thonghyad/istockphoto

4. Boiling Water

We've all done it. The pasta is tender, so you set the colander in the sink, grab the boiling water off the stovetop, and pour the pasta into the colander to drain the water. Nope, think again. Over time, recurrent boiling water down the drain can deteriorate pipes. Instead, wait for the water to cool down a bit before straining and draining. 


5. Coffee Grounds

Think twice before you rinse coffee grounds down the sink. As the coffee grounds travel down the drain, they actually congregate and clump together instead, which can cause build-up and blockages. Opt for the trash can or compost for these grounds instead. If you do the latter, your garden will thank you.

Fresh milk being poured down a stainless steel sink, waste

6. Milk

Next time you go to make a morning bowl of cereal and take a whiff of the milk and discover its gone sour, do not head for the sink. Dairy down the drain can also cause clogs if the milk has curdled, and it can be harmful to the environment, too. Try composting it instead.

Paint cans and paint brushes and how to choose the perfect interior paint color and good for health
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7. Paint

Depending on what type of paint you're looking to dispose of, the recommended method varies, yet one thing remains the same regardless of type: Do not rinse it down the drain. If you're dealing with oil-based paint (which is considered hazardous to the environment), you should avoid discarding it in the trash, even if you dry it up first. Instead, contact your local Hazardous Household Waste collection center. If you need to dispose of latex paint, try leaving the lid off of your can outside if there is only a small amount left, letting the air dry it out before tossing in the trash. Otherwise, try tossing in some kitty litter to turn it into a solid before throwing it away.

Cooking Rice Congee - food preparation.
Adisak Mitrprayoon/istockphoto

8. Rice

Cooking rice is magical. You pour one small-looking cup of dry rice into water and by the time it's done cooking, it doubles itself. Remember that act of expansion as you're doing dishes after dinner. Do not rinse rice down the drain, because once it mixes with the water, it will expand, and can ultimately clog your pipes.

Cough Syrup

9. Medications

If you have leftover medication to dispose of, do not rinse it down the drain. Adding these medications to the drain field can lead to water pollution. Discard medications in the trash or check with your pharmacist or city services for recommended disposal methods. 


10. Flour

If you've ever tried to rinse flour off your hands, you know it creates a messy, gloppy goop when it mixes with water. Avoid breeding that goop in your drain and toss leftover flour in the garbage instead of the sink. Same goes for any type of dough!

Sink drain cleaning process using baking soda and white vinegar
Andrei Zonenko/istockphoto

Safe to Pour Down the Sink

There are plenty of off-limits items you should keep away from your drain, but there are also a few that are great to keep in mind if you're trying to clean your drains, including:

  • Salt
  • Vinegar
  • Hyrdogen peroxide
  • Baking soda
  • Cola and other sodas