how to dispose of cooking oil

It’s important to know how to dispose of cooking oil responsibly. According to the EPA, vegetable oils and animal fats can have the same devastating impact on the environment as petroleum.

Luckily, there are plenty of other ways to dispose of used oil from the kitchen that won’t clog your drains or harm the environment!

Why you shouldn’t pour cooking oil down the drain

Cooking oil, like other types of grease and fats, will stick to the sides of pipes, quickly building up until the pipe is partially or entirely clogged, and can even damage the walls of your drain line.

If you pour used cooking oil down the drain, it can clog not only your home’s drains, but also the whole local sewage system.

The same goes for flushing cooking oil down the toilet. Some people think this is a safe way to dispose of old cooking oil, but it will end up clogging your drains and sewage system in the same way as if you pour it down the sink.

And of course, you don’t want to put loose oil in your household trash. Not only will this create an unholy mess and attract bugs and vermin, but it can also pose a risk to sanitation workers.

used cooking oil in a wok pan
It may be tempting to just pour used oil into the drain. But you will end up with clogged pipes plus a polluted environment.

Disposing of used cooking oil in any of these ways can also negatively impact on the environment. Because cooking oil is not biodegradable, it will not break down but will eventually make its way into rivers or oceans where it will pollute these waterways.

Once there, it can be extremely hazardous to flora and fauna in a range of ways, including coating animals and plants, meaning they can’t absorb oxygen and literally suffocate. This can have devastating impacts on the ecosystem over time, destroying food supplies and entire habitats.

How to dispose of cooking oil responsibly

Given cooking oil’s negative impacts, from clogging the drains in your home to destroying natural habitats, it’s important to learn how to dispose of cooking oil responsibly. Thankfully, there are plenty of alternatives to pouring kitchen grease down the drain!

Recycle it

Cooking oil can be recycled in some cases: some recycling facilities take cooking oil under the category of household hazardous waste (HHW). Use a finder tool such as Green Citizen’s Green Directory, Earth 911, or contact your local sanitation department to find a recycling center in your area.

green citizen cooking oil recycle search results
Online search is a great way to find recycling centers nearby

These facilities recycle cooking oil into biofuels which are then used to generate electricity or to power vehicles. These fuels include biogas, which can be burned to produce electricity, and biodiesel that can be used in most diesel cars and trucks.

Not only is this a great way to keep your used oil out of the natural environment, but biofuels are a renewable source of energy that burn cleaner than petroleum-based fuels – so it’s an eco win-win!

How to dispose of cooking oil: recycle it

Here’s how to dispose of cooking oil properly – through recycling it:

1. Find a recycling center. Get in touch with your local authority and see if they offer options to recycle used cooking oil. If not, check the Green Directory or Earth 911 to find a recycling center in your area.

2. Prep the oil for recycling. Ask the recycling facility how they would like you to send in the oil – they may ask you to put it in a recyclable container such as a milk carton or plastic bottle. You may also find it easier to freeze the oil in order to deal with it as solid waste.

3. Wait for the container to fill. If you don’t have a large quantity of used cooking oil on hand, store the oil in the container and keep adding to it as you generate more oil. Once it’s full, it’s ready to recycle!

4. Take your old oil to the recycling center. Again, check with the facility to find out how you can submit your old cooking oil for recycling. In most cases, you’ll need to take it to the recycling center, though some facilities only accept HHW during certain periods, while others may pick up your old oil if you pre-arrange it.

How to dispose of cooking oil: compost it

Pure vegetable oil, such as 100% olive, coco, corn, soy, sunflower, or grape-seed oil, is fully compostable, so you can add it to your household compost bin.

A bit of cooking oil in your compost is actually a good thing as it attracts earthworms which love to eat this greasy treat and will help to turn your compost into nutritious mulch for your garden.

However, be careful not to add too much oil in proportion to other food waste, as this may attract less desirable critters. Excessive amounts of oil can also form hydrophobic barriers, which block the necessary flow of air and water around your compost.

You can technically compost animal fats, but the risk is that it will likely attract a lot of bugs and small animals to your compost bin. The same can be true for vegetable oil that was used to cook meat.

How to dispose of cooking oil: reuse it

Another eco-friendly way to dispose of your used cooking oil is to reuse it, either in the kitchen or for another purpose entirely.

For cooking

If the oil is still clean enough, you can use it again to cook more tasty food. You can use cooking oil between two and six times, depending on what you used it to cook.

When you use oil for cleaner-cooking foods like fries, you may be able to use it up to six times. However, you’ll get fewer uses when frying breaded treats like fried chicken – you’ll only be able to use the oil two to four times before it takes on a murky green hue that indicates it’s past its best.

fries in boiling cooking oil
Depending on the previously cooked foods, cooking oil can be reused up to 6 times

As a general rule, if it still looks normal, the texture hasn’t changed, and it smells ok when you heat the oil to high temperatures, it’s still good to use!

To store cooking oil for reuse, wait for it to cool, then put it in an old glass jar, seal it, and store in a cool place. To ensure your oil is suitable for reuse, it’s a good idea to strain it through a piece of cheesecloth or kitchen strainer before storing it.

Just be sure to wipe the oil off the strainer before washing it to avoid it going down the drain!

Keep in mind that the flavors of the food you cook get absorbed by the oil they’re cooked in, so it’s a good idea to store used cooking oil from different dishes separately. For example, you should have one jar for oil used to cook chicken, another for oil for seafood, and another for fries. Be sure to label each jar clearly.

It’s a good idea to refrigerate used cooking oil to extend its life until you want to use it again.

Oil can go bad, just like any other food item. This could pose serious health risks if you use the oil. Cooking oil stored in the refrigerator typically extends the expiry date two times over.

If you want to store the oil for even longer before reusing it, you can freeze it for up to a year. The oil should completely freeze in around a day.

This is also a good way to store unopened oil – new, sealed cooking oil will last about a year in the pantry and two years in the freezer.

How to dispose of cooking oil: upcycle it

One fantastic way to upcycle your old cooking oil is to make soap. Making soap from scratches involves some kind of fat as a key raw ingredient, so why not use leftover oil from your kitchen?

In fact, olive oil-based soaps are highly valued because they’re great for sensitive skin, rich in vitamins, and have anti-aging properties. Check out these cool ideas for making your own DIY soaps.

You can also make weed killer or insecticide from used vegetable oil. Not only is this a great way to recycle your kitchen waste, but it also represents an eco-friendly alternative to chemical-based products.

Simply mix one cup of used vegetable oil with one tablespoon of biodegradable dishwashing liquid in a container, then dilute two teaspoons of the mix in one quart of water. You can then spray the diluted mixture on to your plants to drive away pests, or directly on to weeds.

Use a hazardous household waste service

Another option for responsibly disposing of your used cooking oil is to use a household hazardous waste (HHW) disposal service. These are companies which will usually come to your house and collect your dangerous and difficult-to-deal-with waste, for a fee of course.

This can be an expensive way to get rid of a small amount of cooking oil, but you can make it worth your while by having the service collect other types of waste that you can’t throw in the trash. These companies typically accept materials such as medical waste, paint, cleaner products, pesticides, and batteries.

Get a grease disposal kit

These kits contain everything you need to easily and safely dispose of used cooking oil and other household grease. They typically contain foil-lined bags that you can fill with used oil, seal, and safely throw in the trash.

There are a range of retailers that sell these kits, such as Bed, Bath, and Beyond, and you can also find them online.

However, this is not a very eco-friendly option, as they typically contain aluminum, plastic and other non-biodegradable components that end up in landfill as you use the kit.

Take it to a local restaurant

Restaurants throw out a lot of used cooking oil and so have their own systems for oil waste disposal. Therefore, if you have a friend or family member who owns a restaurant you could ask them to throw out your cooking oil with theirs.

Or you can simply go to a local restaurant and ask if they’d be willing to take your old cooking oil.

Put it in a container and throw it in the trash

Although you should never pour oil directly into the trash can, you can dispose it with your regular household garbage as long as you handle it correctly. Once the oil has completely cooled down, you can pour it into a container such as an empty milk carton, plastic bottle, or take out food container.

used cooking oil in big plastic bottles

As long as it is tightly sealed, you can then put that container in the trash and dispose with your normal household waste. However, avoid using plastic bags to hold the oil before putting it in the garbage – these aren’t strong enough and oil may leak out.

While this is safe to do, it is not exactly responsible, as it means that the container cannot be recycled. For example, milk cartons can be recycled curbside in some areas or through mail-in programs, but not if you fill them with oil and throw them in the trash.

Frequently asked questions

Recycling used cooking oil can be somewhat complex, so we’ve pulled together the answers to the most frequently asked questions on the topic!

Can you recycle cooking oil?

Yes, you can recycle cooking oil, though you won’t be able to recycle it curbside. Some recycling centers accept used cooking oil as part of hazardous household waste (HHW).

a black bin for spent cooking oil
A bin for spent cooking oil in Austin, Texas
Source: Wikimedia / WhisperToMe

If you can’t find a recycling center in your area that takes cooking oil, you can also compost, reuse or upcycle your kitchen grease.

How do I know it’s time to dispose of my cooking oil?

Like most other foodstuffs, cooking oil can go bad and, once this happens, using it for cooking could put your and your family’s health at risk. Besides checking the expiration date on the label, you’ll know that the oil has gone off if there are changes to the appearance, texture, or odor of the oil.

What should I do with expired cooking oil?

Cooking oil generally lasts around one year if stored at room temperature in the pantry. You shouldn’t use oil that is past its expiration date, as this can be a health risk.

The same goes for cooking oil that has been reused too many times – if it’s changed in color, texture, or smell, you should dispose of it.

You can dispose of expired cooking oil responsibly by recycling, composting, or reusing it. Never pour oil down the drain or put it in the trash unless it’s in a sealed container!

You can also extend the life of your cooking oil by storing it in the fridge or the freezer.

Can you freeze cooking oil?

It’s easy to freeze cooking oil – simply put it in a container and then place it in the freezer. It should completely freeze within a day.

Wrapping up

If you want to know how to dispose of cooking oil responsibly, the first thing you need to know is that you should never pour it down the drain, into the toilet, or directly into the trash! You can place the oil in a sealable container and then put this with your regular household trash.

Better yet, recycle it, reuse it, or compost cooking oil that hasn’t been used to fry meat.

If you are concerned about the impact of used cooking oil on your drains and the environment, the best thing you can do is to use less oil. Not to mention that cooking lighter is much better for your health!

Consider baking or steaming your food instead of frying it, or invest in an air fryer to slash your use of cooking oil.

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