The garbage disposal is one of the most useful appliances in your kitchen. Installed in roughly half of American homes today, garbage disposals have gone from being prohibited by law in many localities (New York City famously banned them until 1997) to being a common feature in newer homes in just a few decades.
Given their relatively recent adoption, it shouldn’t be surprising that there are a lot of myths about garbage disposals. While some of these misconceptions are harmless, others have the potential to cause serious damage to your disposal unit or your pipes.
Here are five of the most common myths:
1: Garbage Disposals Have Blades (and You Can Sharpen Them)
As exciting as it might be to picture a whirling chamber of razor sharp blades inside your disposal, the reality is much more practical. Rather than blades, disposals use a system of small, shredding impellers or teeth that spin at high speeds to grind up food waste. The system works a bit like a cheese grater, and while it doesn’t involve whirling blades, you still shouldn’t stick your hand inside the unit while it’s operating.
Another myth associated with this one is the idea that you can sharpen the disposal’s blades by grinding up ice. Since the unit doesn’t have any blades, dumping ice down the drain won’t accomplish much more than pouring water down the drain. Some people recommend using egg shells for the same purpose, but this can cause significant damage to both the disposal and your pipes. The shells’ membrane layers can become entangled in the impellers and the ground up particles can easily create clogs in your pipes.
2: You Need to Run Hot Water When Using the Disposal
While running cold water can help flush food waste particles down the drain, using hot water can actually cause problems. Hot water causes oils and fats to remain in liquid form, allowing them to easily flow down your drain and then revert to their solid form when they cool deeper down the pipes and create clogs.
Ideally, of course, you shouldn’t be putting any fats or oils down the drain, but forcing them into the disposal with cold water will at least keep them in their solid form. Once ground up into tiny particles, they’re less likely to cause clogs as they flow through the plumbing with the rest of the food waste.
3: Lemons Can Clean the Disposal
It may be true that running lemons or limes through the disposal makes the sink smell better for a short time, but that doesn’t mean it’s any cleaner. The citric acid in these fruits isn’t strong enough to actually disinfect or remove stale food from the disposal, but it can cause the metal inside to corrode over time. Even worse, that pleasant citrus scent can mask the foul odors that might otherwise warn you of a more serious problem in your plumbing.
4: You Can Put Any Food Waste in the Disposal
The garbage disposal is a remarkable piece of technology, but it has limitations. Hard, solid waste such as egg shells, chicken bones, or fruit pits will break or wear down the disposal very quickly. Stringy, fibrous foods like corn husks, celery, and banana peels can become entangled in the impellers and plug up the drain. Starchy materials like potato peels are often quite difficult for disposals to handle.
As a general rule, if it’s something you can’t chew, then your garbage disposal probably can’t either. When in doubt, you’re better off tossing the waste in the trash can rather than risking damage to your disposal or your pipes.
5: Garbage Disposals are Bad for the Environment
Many of the old legal restrictions on garbage disposals were motivated by concerns over the amount of food waste they would add to public sewer systems. While this may have been a concern for the water treatment facilities of past decades, modern wastewater processing systems are more than capable of handling anything a disposal can force down the drain.
In fact, treating food waste in the water is far more energy efficient than disposing of trash in a landfill. Even setting aside the transport costs, food waste in landfills generate harmful methane gas that contributes to air pollution. When separated from the wastewater, the gas from decaying biomatter can be easily captured and converted into useful energy.
By sorting out the truth about your garbage disposal from the widespread fictions, you can take active steps to ensure your unit remains in peak operating condition for years to come. However, in the event that your mother-in-law shoves the leftover chicken wings down the disposal, it’s good to have experienced plumbing professionals you can rely on. Problems with a disposal can often lead to problems with its associated drains and pipes, so it’s often a good idea to consult an expert when something goes wrong.