Invented in 1972, the garbage disposal is one of the most depended-on appliances in the kitchen. This appliance is standard in most homes today, and some of us would be utterly lost without one. But how much do we know about how this little gadget works? Do you know some less obvious things that don’t go down the drain? Do you know the things that are good for the garbage disposal? Let’s discuss what belongs in the disposal and, more importantly, what does not belong in it.

What Is a Garbage Disposal and How Does It Work?

A garbage disposal is a reservoir mounted underneath your kitchen sink. It is connected to your drain so that everything you wash down the sink goes through the disposal before entering your drain pipes. Inside the reservoir are blades and teeth that help push food through and pulverize it, making it safe to flush through the sewer. Your garbage disposal uses electricity to run, so it must be connected to a power source. You also must run water while the disposal is running to help move the ground-up food through your pipes. Before flipping the switch to turn on your disposal, get your water running and keep it running for about 30 seconds after you’ve turned the disposal off.

Things That Are Safe for the Garbage Disposal

In theory, a garbage disposal is designed to allow for food to go down the drain rather than throwing it in the trash. Using your garbage disposal means less solid waste and cuts down on the stinky stuff in your garbage can. This isn’t true for all foods, but many foods are safe to put down the drain connected to a garbage disposal.

Ice Cubes

Tossing a couple of ice cubes down the drain is shown to be beneficial to your garbage disposal. The large chunks of ice work to push around and scrape up any food residue sitting down inside your disposal, helping to clean it out and wash these foods away.

Citrus Fruits

Lemons, limes, and oranges are not only safe for your garbage disposal but can be beneficial as well. Tossing some citrus down your drain can help freshen up your disposal. Be sure the peels and rinds are cut into smaller pieces so you don’t overwork your machine.

Liquids and Soft Foods

Most liquids and soft foods are safe for your garbage disposal. Along with water, these should flush down without clogging your drain. It is typically thought that if it is safe to feed a toddler, it is soft enough to go through the garbage disposal. Beware of the list of no-no foods below though, as these can create a damaging situation.

Dish Soap and Cold Water

While running cold water down the drain, pour in a bit of dish soap. This will help clean your garbage disposal and eliminate lingering odors.

Things You Should Never Put Down the Garbage Disposal

Don’t be fooled into thinking you can put anything you want down the drain just because you have a garbage disposal. Some food items can wreak havoc on your disposal while others will clog your drainage system. These food items should be tossed in the trash rather than flushed down the drain.

Grease, Oil, and Fat

Hot grease, oil, and fat may seem safe due to being a liquid, but you should never pour these fluids down your drain. As they cool, they will harden, clogging up your garbage disposal and pipes. Instead, pour your grease into a jar and wait for it to cool before tossing it in the trash.

Oily Foods

Oily foods are sneaky as it isn’t quite the same as pouring oil down the drain. However, the oil in the food can still linger inside your disposal and eventually create a clog.


Animal bones from food are hard and irregular in shape and sometimes jagged. Placing them in the garbage disposal makes your machine work harder. It also creates a potential risk of damaging your drains and getting stuck. When the bones get stuck, they will collect other food waste and plug up your pipes.

Coffee Grounds

Coffee grounds may seem harmless but are one of the top things plumbers see in clogged drains. The grounds clump together when flushed with water rather than floating apart or dissolving, creating a clog risk.


When mixed with water, flour clumps form a mass. If you dump flour down the drain, you face the risk of a ball of dough forming inside your disposal.


Some people recommend putting eggshells down the drain as a way to sharpen the blades in your garbage disposal. This is a dangerous idea as there are sticky membranes inside the shell that stick to the components of your disposal and can create a breakdown over time.


The fibrous strands of celery tend to wrap around the blades and other parts of your garbage disposal. Over time, this will cause the disposal to slow down and burn out. Other fibrous and hard vegetables such as asparagus, lettuce, and corn husks should also be avoided. Vegetables are great for composting or tossing in the backyard for wild critters.

Pasta and Rice

When mixed with water, pasta and rice expand. This creates a gooey situation in your garbage disposal where the food will stick and build up. Cooked or raw, pasta and rice should be tossed in the trash.

Potato Peels

Starchy vegetables, such as potatoes and their peels, should be kept out of the garbage disposal. These foods tend to collect in the drain and build into a sludge, creating a backup.


You may be rolling your eyes right now, but some people do toss trash down the drain. Wrappers, fruit stickers, and paper towels are top items people erroneously feel are safe to go down the drain. Non-food items should always be tossed in the trash and never washed down the sink into the garbage disposal.


Yes, even the chemicals marketed to clean your drains should be avoided. Drain cleaners and unclogging agents should be avoided as they are harsh and cause your drain and garbage disposal to weaken over time. Use soap and water as discussed above to clean your drain and disposal. If you have a clog that plunging won’t fix, call a licensed plumber to avoid further damaging your plumbing system.

Knowing what should and should not be washed down the drain into your garbage disposal is an important step to protecting your plumbing. Following the information listed here will help you keep your pipes clear of clogs and your garbage disposal fully functioning. If you find yourself needing professional repairs, call We Care Plumbing, Heating and Air. We’ve been providing trustworthy, skilled plumbing services in Southern California for over 20 years and will make sure your garbage disposal and pipes are up to par.

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