Most people don’t think twice about pouring oil down the sink. It’s liquid, so it must wash away, right? But that one small action can create major problems. As it cools, the oil can solidify inside your pipes, sticking to the walls and catching other debris until you’re facing blocked drains, bad smells, and potential plumbing repairs. From there, it can move through the sewer system and into natural waterways, where it chokes oxygen levels and puts aquatic life at risk.
It’s one of the reasons Environmental Oils offers a free collection service for used cooking oil, to help stop the damage before it starts. So what actually happens when you pour oil down the sink? And how does oil spill affect the environment? Let’s take a closer look.
The Dirty Truth About Oil Down the Drain
A question we get often is: Can oil go down the sink? The short answer? Absolutely not.
It might seem harmless, pouring a bit of leftover oil down the sink after frying up dinner. But give it a few hours and that warm, runny oil starts to cool and harden. What was once a liquid slips into your pipes and sticks around, literally. It clings to the side of your plumbing, building up over time and catching whatever else goes down it.
Once that buildup starts, the consequences can stack up fast:
- You’re looking at blocked drains that backup sinks and dishwashers.
- Plumbing repairs that aren’t cheap, especially if the blockage is deep in the system.
- Overflows or leaks that can cause property damage – plus water damage which tends to snowball if it’s not caught quickly.
And it doesn’t stop there.
That oil continues its journey through the sewer system, where it mixes with things like wet wipes, nappies, and other waste. The result? Fatbergs. Huge, rock-slid clumps that clog up entire sections of the network. One in London got so big it nearly caused raw sewage to flood the streets. It took a full crew in full-body suits to dig it out by hand, and they said it was like trying to break through concrete.
Where the Oil Inevitably Ends Up (And Why It’s a Problem)
It might seem harmless in the moment. Tip the pan, rinse with hot water, and it’s gone. Unfortunately, pouring oil down the sink doesn’t make it disappear. It just sets off a chain reaction underground. And yes, we’ve heard the question before: Can you put cooking oil down the sink if you flush it with hot water? Still no. That combo might delay the damage, but it doesn’t prevent it.
Once it hits the sewage treatment system, the problems stack up fast. These plants are designed to handle wastewater, not greasy buildup. Here’s what starts to go wrong:
- Oil clogs machinery, slows down operations, and sends maintenance costs through the roof.
- It messes with the biological treatment process, making the plant less effective.
- In worst-case scenarios, untreated sewage can end up discharged into the environment.
And even if it makes it past all that, the oil doesn’t vanish there. Worst of all, it ends up in our waterways, spreading across the surface and cutting off oxygen. That suffocates fish and plant life, and weakens ecosystems we all rely on, whether we realise it or not.
The great news is, oil isn’t waste if it’s handled properly. In the UK, data from the Renewable Transport Fuel Obligation shows that recycled cooking oil now accounts for 28% of certified sustainable biodiesel. It’s the most widely reported feedstock, showing just how much value cooking oil recycling can actually deliver.
The Responsible Choice? Recycling with Environmental Oils
It might seem like a small thing, but what you decide to do with leftover oil can have a big impact. Environmental Oils offers a smarter alternative to pouring oil down the sink, helping households and businesses in Australia recycle it properly instead. We offer a free collection service, making it easy and convenient to deal with used oil the right way.
This work supports genuine environmental outcomes too, with every pickup handled in line with local regulations and sustainability goals. With over 20 years in the game, we’re also accredited by the Australian Renderers Association and ISCC, which means you’re working with a team that knows exactly what they’re doing.
If you still have questions, like can oil go down the sink? Or wondering how to dispose of oil at home, the easiest answer is to let a team of experts take care of it. Contact Environmental Oils now to book your free pickup.
How Environmental Oils Australia Makes a Difference
It’s surprising how much value can come from what many see as just used oil. Environmental Oils collects the oil and passes it on to specialist facilities where it’s recycled into renewable energy and animal feed, giving it a second life instead of going to waste. This process helps reduce reliance on fossil fuels and supports sustainable farming practices.
Choosing our service comes with a range of benefits:
- Protect the environment by keeping oil out of waterways and drains, which helps preserve local ecosystems and wildlife.
- Enjoy the convenience of free, reliable oil collection that easily fits into your schedule.
- Stay on the right side of regulations and avoid potential fines – all while showing a commitment to eco-friendly practices.
Take Care of Waste Oil the Right Way
Out of sight doesn’t mean out of impact. Pouring oil down the sink might feel like the easiest option, but it leads to blocked pipes, overloaded treatment plants, and pollution that seeps into rivers, oceans, and the environments we all depend on. It doesn’t disappear; it lingers, causing bigger problems for waterways, wildlife, and clean-up efforts in the future.
Let Environmental Oils handle it properly. Our free oil collection service makes it simple to keep waste oil out of the wrong places, while giving it a chance to be reused in a way that actually helps the planet.
