Is Olive Oil Biodegradable? (And Ways to Dispose of)

Olive oil is one of the healthiest options for lubricating your food. It contains low amounts of fat, and even then, this type of fat is regarded as healthy. As such, olive oil is pretty popular in the kitchen. Olive oil is anti-inflammatory, prevents stroke, protects your heart, reduces type 2 diabetes, among many other benefits.

It’s also very useful outside the kitchen. For instance, you can use olive oil as a moisturizer for your face. The cosmetic industry also enjoys the benefits of olive oil, and it’s used for the production of a range of cosmetics. Olive oil is also medicinal – you can consume it raw.

Since you know the many benefits of olive oil, you likely have a large amount of it in your home. Well, if you’re curious about the ways to dispose of it, then you’ve come to the right place. If you also have other questions about olive oil, then please, read on. We’re certain we’ll be able to answer these questions adequately.


Does Olive Oil Biodegrade?

Biodegradation can be regarded as nature’s way of disposing of our waste. Any material that can break down fast is biodegradable. However, biodegradation doesn’t happen independently. Instead, some factors come together to facilitate this process.

Now, for biodegradation to occur, there must be factors like microorganisms, moisture, oxygen, and heat. Any biodegradable material will not just break down; it’ll break down fast.

Of course, during the process, it won’t leave any negative impact on the environment. Typically, this is because most natural resources are biodegradable. But, again, natural resources come from nature, so they aren’t capable of harming it. 

Is olive oil biodegradable? Well, it is, and research has shown that 70 to 100% of its components will break down within 28 days.

It’s only reasonable to expect that olive oil is biodegradable; after all, it’s made from olives and has no artificial additive. As such, microorganisms will have no difficulty feeding on it and breaking it down.

So, when you spill some olive oil into the environment, you don’t have to worry about it leaving negative impacts or remaining on the soil for a prolonged time. Instead, it’ll be entirely or almost broken down within four to five weeks.

Does Olive Oil Expire?

Bulk purchases save you good money. So, we sometimes find ourselves buying more than we can use within the shortest period. Now, is it a good idea to bulk-purchase olive oil? Remember, it’s made from fruits, so it’s a form of fruit juice, per se.

You may wonder if olive oil has an expiry date. Well, it certainly does, and we’ll break this down for you.

Typically, the less processed olive oil, or extra virgin olive oil, lasts for about 12 to 18 months after it’s been bottled. The more processed ones can last as long as 18 to 24 months, and that’s because they’ve been altered to last longer.

Now, you have to consider that the expiry date starts from the bottling day, and it doesn’t arrive at your local supermarket that same day. Instead, it undergoes a long journey from where it was manufactured – the countdown already started.

As such, your olive oil may not even last as long as you want it to before it hits its expiry date. So, it’s best to finish the oil 30 to 60 days after you open the bottle. At most, ensure your olive oil doesn’t exceed a year.

It won’t poison you when it expires. You see, the expiry date on the bottle doesn’t necessarily mean that’s the day it’ll go bad. It’s just there to give you an insight into when the product starts losing its value.

You’ll know your olive oil has gone bad because it’ll develop a rancid taste. So again, you won’t get food poisoning from expired olive oil. However, you’ll know it has gone bad from the taste it gives.

If you’d like to know before using it for cooking, you can smell it. Rancid olive oil smells a bit like fermented fruit. Alternatively, you can do the swirl test, and here you’ll put a teaspoon of olive oil to gauge the taste – you’ll certainly be able to differentiate between what tastes normal and what’s gone bad.

Can You Dispose of Cooking Oil in Your Compost Pile?

Once your cooking is done, proper disposal of the oil is an important waste concern. Most people immediately pour their used oils down the drain and assume that’ll suffice, but the reverse is the case. Drains do not have a proper grease management system, and so the problem continues.

Composting is then assumed to be the next best solution. But can cooking oil be composted? You’ve probably tried googling to get an answer to this question. But a simple google search might not provide an adequate answer because the answer is not so straightforward.

In simple terms, you should not compost waste cooking oil. This is because some wastes are more complex than others, affecting the time it takes to break down.

Cooking oils fall into this category of ‘more complex’ waste because they take longer to break down than other waste products like fruits, papers, etc.

Pouring cooking oils in your compost bin can also make it difficult for oxygen to get through, which will make your pile anaerobic rather than aerobic. Anaerobic compost piles can still eventually break down, but it takes longer, is very slimy and smells worse during composting.

However, some types of organic cooking oil can be composted in small amounts. For example, you can compost vegetable oils such as sunflower oil, coconut oil, peanut oil, olive oil, rapeseed oil, corn oil and soybean oil in small amounts.

But they must not come in contact with other foodstuffs such as meat, cheese or fish. Also, if they have been used to the oil to fry fish or meat, you need to be more careful when adding them to a compost pile as the smell of rotting meat or fish or cheese can attract rodents. 

You can soak up these oils in a paper towel, paper plate or a piece of cloth you’re willing to dispose of, but it’s not advisable to pour the oil directly into your compost bin.

Also, if you have a large compost pile that will attain a temperature of about 120°F, you can put a little more vegetable oil in it.

Also, you can use hot composting when adding oils to your compost pile as it’ll break down the fat faster.

Nevertheless, the problems experienced while adding waste cooking oil to a compost heap greatly outweigh the benefits. So, to save yourself and your garden the stress, don’t compost cooking oil.

Can You Throw Olive Oil Down the Drain?

Most seasoned chefs will agree that deep-frying, stir-frying, grilling, searing and shallow frying are cooking processes that require artisan oils such as olive oil to complement your flavors and properly cook your ingredients.

But as a homemaker whose priority is to feed your family with mouth-watering dishes, once your cooking is done, the first thing that most likely comes to your mind is to put your used dishes, pots and pans in the sink, including those containing used oil; and also pour leftover oil down the drain.

Well, if you’ve been doing this, it’ll be better for the environment if you stop. Pouring olive oil down the drain can harden the pipes and create fatbergs.

Fatbergs are soapy, waxy substances created as a result of cooking oil coming into contact with chemicals from cleaning supplies, the oxidation of pipe systems, and decomposing waste.

As fatbergs are created, they stick to the wall of the sewers and pipes and begin to collect bits of debris like coffee grounds or food crumbs that stick to their surface and grow very large over time.

Fatbergs can destroy pipelines and sewer systems. Fatty masses can grow and clog pipes which will hinder them from working effectively. In addition, very large fatbergs can lead to flooding, backwashes and can be very expensive to repair.

Sewer floods and backwashes can wash garbage and raw sewage in the areas and streets around them. This can lead to contamination of plants and wildlife with toxic elements and also cause damage to the environment as well as public health risks. They can also block water treatment processes, becoming dangerous to the water supply within that environment.

How to Dispose of Used Olive Oil?

Many people assume that pouring used olive oil down the drain is the perfect way to dispose of it. But now that we know that this causes detrimental effects to sewage systems, pipes, and the environment at large, what other ways can olive oil be safely disposed of to stop this unsanitary phenomenon?

The first way to safely dispose of used olive oil is to freeze it. You can also freeze your olive oil whether you plan to reuse it or throw it out. Let the oil cool and pour it into an airtight container. Then, you can place it in your freezer and wait for it to solidify. This makes it easy to get rid of the oil.

Used olive oil can also be converted into biodiesel by combining it with alcohol like methanol. It can be a suitable replacement for petroleum because it’s potentially less damaging to the environment and does not release harmful greenhouse gases into the environment when turned into fuel for machines and equipment.

However, most homes do not generate enough cooking oil for this, so it’s advisable to contact your local restaurants to check if they participate in converting olive oils to biodiesel.

Finally, you can combine your used oil with other materials like sawdust, flour, sand or cat litter until the consistency is thick and can be easily thrown out. These materials readily absorb the liquid and prevent you from worrying about oil leaking through your garbage bags or spilling.  

You can also use your used olive oils to kill weeds. Place your oil in a small spray bottle and spray those pesky nuisances in your garden.

If you plan to deep-fry foods anytime again or fry foods often, you might want to store it in an airtight container and store it somewhere dark until you are ready to use it again.

Before you store it, however, you should strain the used oil through a sieve or a piece of clean cloth or a coffee filter to get rid of any debris in it. 


Cooking oil is indispensable in the kitchen – we need it to make an array of dishes and balance our nutritional needs. However, disposing of the leftover oil is a tricky feat, and most people don’t know how hazardous it can be to the environment.

But now you do! So please, make conscious efforts to dispose of your leftover oil in a way that favors the environment henceforth.

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About Rinkesh

A true environmentalist by heart ❤️. Founded Conserve Energy Future with the sole motto of providing helpful information related to our rapidly depleting environment. Unless you strongly believe in Elon Musk‘s idea of making Mars as another habitable planet, do remember that there really is no 'Planet B' in this whole universe.