
In terms of things that are hard to get rid of, cooking oil is up there with cold callers and Bounties at Christmas. Follow our guide to discover how to dispose of cooking oil responsibly, without needlessly damaging your plumbing or the planet. You’ll find out why oil isn’t so fantastic for your pipes or the environment, and learn some clever ways to reuse oil at home.
How to get rid of used cooking oil
When disposing of used cooking oil, there are several major no-nos. But that doesn’t mean it has to be a Hurt Locker-esque operation. You can get rid of cooking oil by putting small amounts in your food waste recycling bin, but only once it’s cooled down so that it doesn’t melt your bin bags.
If you don’t have a food waste recycling bin – or are reading this thinking, “What on earth is a food waste recycling bin?” – fear not. You can also get rid of grease lightning fast (see what we did there?) by pouring it into a sealed container and chucking it in your general waste. Containers with lids are the ones that you want (the ones that you want, want) because they stop the grease from spilling into your bin.
You can keep using old jars, lidded wine bottles and sealable takeaway boxes to store your used oil. Then, when they’re full, just throw them in your general waste.
Can you dump frying oil in the sink?

You should never pour frying oil into your sink. Dumping grease down the drain can create fatbergs in your pipes. These greasy, solidified obstructions cause major blockages in your plumbing and local sewers. They can also attract flies, ants and other pests.
“Hold up, what’s a fatberg?”, we hear you ask. Not to be confused with your local takeaway’s best-selling drunken snack, a fatberg is “a large mass of fat and solid waste that collects in a sewer system”. In other words, the last thing you want dwelling in your drain pipes.
Named Fatty McFatberg, seriously, the world’s biggest fatberg was found in London. Finding Nemo would’ve ended very differently if he’d encountered this on his way back to the ocean, as it weighed 130 tonnes and was the length of two football pitches!
Can you put cooking oil down the toilet?
No, you should not be carrying your frying pans to the toilet and pouring oil down the loo. Greasing up your toilet can, ironically, result in a bog-blocking nightmare for your pipes, as the oil congeals and solidifies to form one giant nugget of fat.
So, to summarise: you can’t spell toilet without oil, but that’s not a good enough reason to chuck grease down your loo.
Bonus tip for cat owners: While you can’t chuck oil down your own toilet, you can mix it into cat litter trays. This is because the litter absorbs the grease, making it easier to throw away. Guess this gives “crude oil” a whole new meaning!
What happens when you pour oil down the drain?
When you’re thinking about how to dispose of cooking oil, your method can have a hefty impact on your plumbing and the planet. We’d say, “No pressure”, but that’s exactly what it can cause if you wrongly dispose of it. Thousands upon thousands of sinks and toilets have fallen victim to the dreaded oil clog, which is about as glamorous as it sounds.
Here’s why you shouldn’t pour cooking oil down the sink or toilet:
- – It damages ecosystems: Ecosystems rely on waterways and riverbeds for food, shelter, oxygen and habitats. Pouring oil down the drain exposes animals to toxic chemicals and choking hazards.
- – It’s a threat to wildlife: Oil wastes vast amounts of oxygen when breaking down in water, snatching it from the critters that rely on it to breathe.
- – It puts the “ew” in sewage: Blockages from oily drains push backed-up sewage into streams, rivers and coastlines. This is a major threat to wildlife and our stunning natural landscapes.
- – It’s money down the drain: As well as the shame of admitting to a professional tradesperson that you’ve greased up your toilet, you also have to deal with call-out costs. Fixing a fatberg-filled drain is a needless expense, which can cost upwards of £40 an hour for plumbers. Just think, that money could’ve gone towards a fancy meal out and saved you a night of cooking and disposing of oil!
What to do with used cooking oil (other than throw it away)
There are other things you can do with used cooking oil which don’t involve your wheelie bin. Here at Modern Milkman, we’re Team Reuse over Team Refuse and love nothing more than finding new ways to reduce food waste at home. So, here’s how you can give used cooking oil a new lease (or should we say, grease) of life:
Stick it in your compost
Organic oils like vegetable, rapeseed, olive and sunflower oil decompose in soil and can be added to your compost bin. But only in small amounts. Anything more than the odd oil-soaked paper towel may slow down the composting process.
If you don’t have a compost bin, learn how to make one with our build guide.
Want to know how to compost small amounts of organic cooking oil? Follow our simple tips below:
- 1. Let them cool down to at least room temperature
- 2. Absorb the oil using a paper towel or another home-compostable material
- 3. Put this in a home-compostable bag
- 4. Toss it in your compost bin or on your heap
Be wary that not all oils are ready for soiling. Synthetic oils can leach hazardous chemicals and toxins into the earth, causing harm to plants, animals and humans.
Looking for more composting tricks and tips? Learn how to use eggshells in your garden and discover the best uses for compost.
Stick it in a lamp
Another lightbulb idea: use your used cooking oil in an old-school oil lamp. Follow these instructions from Primal Survivor to learn how!
Use it as lubricant
Get your mind out of the gutter, we mean for creaking hinges and rusty metals.
Clean your car with it
Used cooking oil (providing it’s not dirtied with leftovers) is great for scrubbing dirt from your car. Just pour it onto a cloth and wipe away!
Speak to your local restaurant
In some areas, used cooking oil from restaurants and catering is now being collected, converted and recycled into fuel for diesel cars. But this is in large quantities and organised with companies like Sundance Renewables. Please don’t try this at home with your wheelie bin!
If you live close to a restaurant, there’s no harm in asking if you can put your used cooking oil in their collection bin, especially if you’ve collected a lot.
Looking for more waste-themed wisdom?
You’re in the right place! Now you know how to keep your veggies sautéed and your waste sorted, burn the midnight oil by reading our other waste-saving guides, including how to keep fruit fresh, food miles 101 and our wide range of eco-friendly recipes.
Got the waste-fighting bug? Check out our sustainably packaged groceries available from our fresh produce delivery before you sign up for milk delivery!
Join our milkround
Now you know how to dispose of cooking oil in the right way, you can keep your pipes clog-free and the environment free of waste too.
Here at Modern Milkman, it’s our mission to reduce waste one doorstep at a time. That’s why our doorstep milk delivery, tea subscription and cereal refills arrive on your doorstep in sustainable packaging that you can either return, recycle or home-compost.
For more helpful tips and insightful info on how to be a little greener, take a look at our blog. And if you’re looking for more ways to reduce waste at home, check out our new milk and food products.