Should You Buy A Food Waste Disposal Unit? – Pros And Cons

In the EU, 20% of all food ends up as food waste, according to Insinkerator. Most of this food ends up in your bin – but it doesn’t have to. This will be welcome news to anyone who has had to deal with a smelly bin in the heat of summer!

Instead of binning your food waste, you can use a food waste disposal unit. This appliance, installed in your sink, can be a great way to cut down on the food that goes into your rubbish.

While the demand for food waste disposal units is only starting to grow in the UK, they are commonplace in the US. Almost every house in the US will have a food waste disposal unit installed.

So what’s all the fuss about?

What Is A Waste Disposal Unit?

A waste disposal unit, often referred to as a garbage disposal or garbage disposer, is an electrically-powered device installed under a kitchen sink between the sink’s drain and the trap. Its purpose is to shred food waste into small pieces, typically less than 2 mm in size so that they can safely pass through plumbing.

This system is designed to handle organic items like vegetable peels, fruit scraps, coffee grounds, and eggshells. It’s important to note that not all food waste is suitable for a garbage disposal. Items like bones, corn husks, fruit pits, grease, and oil can damage the unit or create clogs in the pipes. I’ll talk more about what you can and can’t put in a waste disposal unit later.

You May Also Like
Best Food Waste Disposal Units – Quick Kitchen Clean-Up

How Does A Food Waste Disposal Unit Work?

Food waste disposal units are fairly simple mechanisms. Although some would consider a food waste disposal unit to be similar to a paper shredder or a food processor, it’s actually a different mechanism.

Installed between the sink’s drain and its trap, this machine does not chop or shred food particles with sharp cutting blades. Instead, it uses a plate or grinder wheel in order to turn medium-sized food pieces into very small scraps.

The wheel is equipped with pointed impellers, also known as lugs. They spin rapidly to create a centrifugal force. When any biodegradable waste is fed into the unit, the wheel will grind up the food forced against a stationary grinder ring. Any remaining particles are then washed down the drain with water.

So, in a nutshell:

  1. When food waste is put into the sink drain, it falls into the waste disposal unit.
  2. The user turns on the cold water tap and then switches on the waste disposer.
  3. Inside the unit, impellers, which are rotated by the motor, force the food waste against a grind ring.
  4. The grind ring breaks down the food waste into very small particles, which are then flushed by water through the grind ring and out of the disposal and into the drain system.

food waste disposal unit

If used properly, a food waste disposal unit should not clog drain pipes and should be fairly jam-free. Like with all machines, however, food waste disposal units can have some issues.

Firstly, any hard or fibrous food waste may cause jams at any part of the system. Celery, for instance, has long strings that can get tangled in the impellers.

Using non-food particles in the unit, such as dishware, can lead to jams. It’s also important to use cold water with adequate volumes in order to wash the food particles away from the unit. When running the unit, keeping a constant stream of water running will help to prevent this problem.

Finally, using hot or warm water when using the food waste disposal unit is a problem. This might seem counterintuitive, but cold water is best. Hot, or even warm, water can cause liquid fat or oil to pass into the drain pipes.

This can then congeal or harden inside the pipes, leading to clogs down the line. Unclogging the pipe is possible, but can be challenging, so it’s better to avoid this problem.

You May Also Like
11 Accessories You’ll Want For Your Kitchen Renovation

Advantages of food waste disposal units

  • Reduce the volume of food waste – lower the amount of food that ends up in the trash
  • Convenient and hygienic – will reduce any rotting food particles that end up in the trash
  • Easy to install – most kitchen sinks can have this unit installed
  • Keeps food scraps from landfills – may be more environmentally friendly than traditional disposal
  • Requires minimal energy – will only be a small addition to your current energy usage

Disadvantages of food waste disposal units

  • Not as eco-friendly as composting – will reduce waste but not the best overall option
  • Loud – running the unit late or early may disturb others
  • Not every unit will fit in the cabinet – standard food waste disposal units may not fit in small or unusually shaped cabinets
  • Bad odours are possible – bacteria build-up can lead to bad odours if not cleaned well
  • Possibility of problems – all units can jam, overheat, or leak water
  • Requires water to run – may not be ideal when water usage is limited

Top Tip: To keep your food waste disposal unit smelling clean and fresh, throw some ice cubes and a few lemon or lime wedges into it. This will help to eliminate any odours and food particle build-up.

Are Waste Disposal Units Environmentally Friendly?

Waste disposal units can be environmentally friendly in certain contexts. Their primary advantage is that they help reduce the amount of solid waste that ends up in landfills.

When food scraps are processed through these units, they are transformed into a form that can be managed by wastewater treatment plants. This is particularly beneficial when considering that food waste in landfills decomposes to generate methane, a potent greenhouse gas that contributes to climate change.

Additionally, food waste sent to wastewater treatment plants can be repurposed. These facilities often convert the waste into biosolids, which can be used to enrich soil, while the methane produced can be harnessed for energy as biogas. In effect, garbage disposals offer a way to redirect waste into a cycle of use and reuse.

However, the environmental friendliness of garbage disposals is not universal and depends on several factors. For instance, operating these units requires water and electricity, contributing to their environmental footprint.

Moreover, the impact on wastewater treatment plants should be considered. While these facilities can convert food waste into useful byproducts, not all are equipped to capture and use the methane generated.

Waste in landfill

The use of garbage disposals can also indirectly lead to other environmental challenges. They can encourage higher levels of fats, oils, and grease in sewer systems, which may cause blockages and overflows. These incidents are not only damaging to the environment but also expensive to fix.

Lastly, it’s worth considering the overall waste hierarchy, which promotes reducing waste production in the first place, then reusing and recycling. While garbage disposals can effectively manage waste, they might discourage other beneficial practices, such as reducing food waste or composting.

Composting food scraps at home is often seen as a more environmentally friendly option because it enriches soil health and reduces the need for chemical fertilizers.

So, while waste disposal units can be environmentally friendly, their actual impact varies greatly depending on the local infrastructure, waste management systems, and water availability, among other factors.

You May Also Like
How To Design And Build A Sustainable Kitchen: 7 Eco-Friendly Tips

What Can You Put In A Waste Disposal?

  • Fruits – preferably without pits or seeds
  • Vegetables – preferably cooked
  • Vegetable and fruit peelings – such as citrus rinds
  • Plain meats – with minimal fat
  • Combination foods – prepared dishes not overly high in grease or fat
  • Baked goods
  • Cereal

What Can’t You Put In A Waste Disposal Unit?

  • Grease, oil, and fat – these can congeal inside the drain pipe and clog a sewer system
  • Extremely fibrous and stringy food waste – celery and corn husks, for example, can be problematic for less powered units and may cause a jam.
  • Meat bones – most disposals will not be able to grind them properly
  • Anything that is not food waste – packaging materials, for example, will clog and jam a disposal unit
  • Expandable foods such as pasta, rice, and oatmeal – can expand in the unit and clog the pipe

Final Thoughts…

For many households, having a unit installed can be a great option. They offer a simple, effective solution to dealing with your daily food waste.

If you are considering having one installed, make sure to research quality models for the best results and keep up with the usage and maintenance directions. You’ll have an odour-free, potentially, more environmentally friendly kitchen in no time.



Michael from

Michael is a kitchen designer from the UK. He's been designing and project managing new kitchen installations for over 10 years. Before that, he was an electrician and part of a team that fitted kitchens. He created Kitchinsider in early 2019 to help give people advice when it comes to getting a new kitchen.