Waste cooking oil disposal
Waste cooking oil is inevitable in any business with a kitchen, and the latest regulations require them to arrange for its separate collection and recycling.
Dumping it down the drain or simply disposing of it in the general or food waste bin can lead to hefty fines if caught by your regulator.
But don’t fret; correctly managing waste cooking oil is very simple. This article explains exactly how to dispose of it legally and safely, and perhaps even how you can turn it into a new revenue stream!
Contents:
- What is classed as waste cooking oil?
- How to dispose of waste cooking oil
- How is waste cooking oil recycled?
- Environmental effects of waste cooking oil
- Waste cooking oil costs (and profit opportunities)
What is classed as waste cooking oil?
In the UK, waste cooking oil is classified as vegetable oils and fats used in cooking or food preparation. Regular “cooking oil” becomes “waste cooking oil” when it has deteriorated to a point where it is no longer suitable for its intended culinary use.
This occurs when the oil undergoes significant changes in its chemical composition, typically marked by increased acidity, off-flavours, off-odours, or excessive smoke or foam formation during heating. It also includes oils contaminated with moisture, food particles, sauces, soaps, detergents, other oils and fats, and other contaminants.
These oils must be disposed of or recycled appropriately to comply with environmental and waste regulations. When generated by a business, cooking oil waste is a subgroup of commercial food waste.
Waste cooking oil vs Used Cooking Oil (UCO)
Waste cooking oil and Used Cooking Oil (UCO) are terms often used interchangeably but have slightly different connotations.
While “waste cooking oil” refers to any discarded cooking oils, including fats, UCO is waste oil that needs to meet purity standards (i.e., low moisture levels, contaminants, and free fatty acids). UCO can be directly used in biodiesel manufacturing, and producers will typically pay you if you produce it in enough volumes.
💡 According to a 2014 study, the UK generates approximately 700,000 to a million tons of used cooking oil (UCO) annually.
Typical waste cooking oils
Here is a list of typical spent products generated by UK businesses that are officially classified as “waste cooking oils”:
Type of Oil | Business Source | Common Use |
---|---|---|
Vegetable Oil | Restaurants, fast food outlets | Frying, sautéing |
Sunflower Oil | Restaurants, bakeries | Frying, baking |
Olive Oil | Restaurants, cafes | Salad Dressing, light cooking |
Canola Oil (Rapeseed) | Restaurants, food producers | Frying, baking |
Palm Oil | Food producers, restaurants | Frying, processed food production |
Coconut Oil | Restaurants, bakeries | Frying, baking |
Lard | Restaurants, butchers | Frying, baking |
Tallow | Butchers, food producers | Frying, industrial uses |
The majority of these are generated from restaurant waste.
What is NOT considered a waste cooking oil?
Here is a list of foods that can be easily confused as “waste cooking oils” but are not considered within this category:
NOT waste cooking oil | Description |
---|---|
Fresh, unused oils | Oils that have not been heated, used for cooking or prepared into products like dressings. |
Unused solid fats | Unused fats like margarine, lard or tallow. |
Kitchen waste liquids | Non-oil based liquids like water, broths, soups or sauces. |
Dairy products | Items like cream, butter or cheese used in cooking, even when melted. |
Residential vs commercial waste cooking oil
The difference between commercial and residential waste cooking oil lies primarily in the following:
- waste volumes generated, and,
- handling and disposal requirements.
💡 Commercial waste cooking oil cannot usually be disposed of in household recycling centres. For further information, refer to our guide on what is classed as commercial waste?
Commercial waste cooking oil
Commercial waste oil typically arises in larger quantities from restaurants, caterers, and food processing facilities and must be collected and disposed of by licensed waste carriers. The exact compliance requirements differ in each home nation, with Scotland, Wales and Northern Ireland typically being more stringent than England.
Residential waste cooking oil
On the other hand, residential cooking oil accumulates in smaller amounts from household kitchens. While it is preferable to dispose of it at local recycling centres or via special collection schemes provided by the council, local services are often limited.
💡Cooking oil and fat shouldn’t be poured down sinks as it can cause blockages. If you do not have access to a food waste recycling service, put it in a sealed container and place in the general waste bin.
How is waste cooking oil produced?
Any cooking oil used in frying, baking, dressings, or other cooking methods or stored past its use-by date is classified as “waste cooking oil.”
This is because its chemical composition has changed from the original culinary oil due to repeated heating, exposure to air contamination with food particles, washing-up liquids, sauces, etc.
How to dispose of commercial waste cooking oil
Commercial waste disposal is a regulated process involving several steps. While there are slight local variations in waste cooking oil disposal due to varying devolved policies and local council practices, the recommended process is generally the same for all UK businesses:
Waste cooking oil segregation
Any waste cooking oil that can be reasonably separated from other food wastes should be segregated and stored in specialised containers for storage, collection and recycling.
Note that unless your business is trying to produce (Used Cooking Oil) to sell to biodiesel producers, there is no need to process waste cooking oils any further besides reasonably not mixing it with food waste.
💡Safe handling: Cooking oil is flammable and can cause severe burns.
Waste cooking oil storage
Businesses should store waste cooking oil in designated, sealed containers to prevent leaks, spills and odours. These bins must be:
- solid/strong (cannot be a plastic bag),
- kept in sound condition (cannot be broken or fractured),
- kept in a secure but accessible location (that can be kept clean and free of pests)
- easy to clean and disinfect to ensure it doesn’t become a biohazard.
Your business should have enough storage capacity to fulfil its needs and leave a buffer in case of unexpected higher volumes.
Waste cooking oil collection
UK waste regulations mandate that waste cooking oil must be collected and transported by licensed waste carriers to ensure the oil is handled safely and is either recycled or disposed of in compliance with regulations.
The easiest and cheapest way to arrange this is by comparing food waste collection providers available in your local areas.
💡 Don’t be a victim: Waste regulations mandate that your business is responsible for contracting a fully licensed collection service. Your business can receive hefty fines for hiring the wrong people!
Waste cooking oil documentation
All businesses must keep waste documentation for at least two years, including Waste Transfer Notes of each collection, which must detail the quantities of waste oil collected and the details of the disposal process. Your business and the carrier co-sign this.
💡 Not hazardous: Since waste cooking oil is not typically classified as hazardous waste, so filling out a consignment note is not necessary.
How is waste cooking oil recycled?
Waste cooking oil can be recycled into multiple products, with the vast majority used to produce biodiesel for the transportation industry.
Here is a summary of all the possible recycling pathways for waste cooking oil and whether they are followed in the UK:
Recycling Pathway | Description | Done in the UK? |
---|---|---|
Cosmetic and Industrial products | Can be a core ingredient to manufacture soaps, cosmetics, and industrial lubricants, replacing virgin oils. | Yes |
Biodiesel production | Converted into biodiesel through transesterification. Biodiesel can be used as a renewable fuel in diesel engines to replace fossil fuels. | Yes, the majority of UCO is destines for biodiesel production. |
Energy (Recovery) | Co-generation energy facilities use waste cooking oil as a direct fuel for electricity and heat production. | Yes |
Animal feed | After proper treatment to ensure safety, waste cooking oil can be incorporated into animal feed as an energy-rich ingredient. | 0% as it's illegal to use UCO in the UK since 2004. |
Composting | While small amounts of cooking oils will degrade and contribute to a soil amendment, industrial amounts are detrimental to the composting process. | 0%, as it's not feasible at industrial scales |
Unlike commercial glass or metal waste, waste cooking oil cannot be recycled in perpetuity due to degradation over multiple cycles. Once the oil has been used for cooking and as cosmetic or industrial products, it will be degraded into a low-quality organic liquid that is only useful as feedstock for co-generation power stations.
Any waste cooking oil recycling process contributes to the UK circular economy by preventing this useful resource from ending up as waste in landfills or, worse, causing damage to plumbing, sewers or the environment due to its inadequate disposal.
Recycling Pathways for waste cooking oil
Each recycling pathway begins with the reception of the waste oils, where the pertinent documentation is checked and co-signed. In all cases, the waste cooking oils must undergo a cleaning and filtering pre-treatment to remove impurities such as water, solids, and free fatty acids.
Then, each process takes a different route to end with a distinct end product:
Soaps, cosmetics and industrial products
Soap-making: The filtered oil is mixed with sodium hydroxide to form soap and glycerol. The mixture is then moulded, cured, and finished. The process is known as Saponification.
Cosmetics and industrial lubricants: The filtered oil is reacted with alcohol and an acid catalyst to produce esters. The esters are purified and blended with other ingredients to create the final products, including:
- Lip balms, moisturisers, hair products,
- Hydraulic fluids, machinery lubricants, or metalworks fluids.
Biodiesel
To turn filtered waste cooking oil into biodiesel, it has to go through a process of transesterification, separation and purification:
- Transesterification: Mixing the filtered oil waste with an alcohol (usually methanol) and a catalyst (typically sodium hydroxide or potassium hydroxide) to form methyl esters (biodiesel) and glycerol.
- Separation: The mixture is allowed to settle. Biodiesel floats to the top and is separated from glycerol and other by-products.
- Purification: The resultant biodiesel is purified through washing and drying to remove any residual catalyst, alcohol, and by-products to meet the required quality standards (such as EN14214 in the UK) for certification.
Biofuel is an important additive to regular petrol to reduce the effective carbon emissions of diesel engines.
Used cooking oil is recycled into biodiesel at the following UK facilities:
- Olleco: Located in Liverpool, Olleco operates the UK’s largest biorefinery dedicated solely to processing used cooking oil into biodiesel
- Greenergy: Greenergy operates two biodiesel manufacturing plants on the east coast of England, located in Hull and Newcastle.
Energy recovery
A proportion of waste cooking oils generated in the UK are sent to co-generation power stations such as the 18-megawatt REG Bio-Power Plant at Whitemoor, North Yorkshire, which serves for grid stabilisation purposes when requested by the national grid.
The used oils are also filtered to remove impurities, resulting in bioliquids best suited for combustion and generating the fewest emissions. These generate heat and electricity in specialised boilers designed to run optimally on this fuel source.
💡 While this process is essentially ‘waste-to-energy’ energy ‘recovery’, it is typically not categorised as such because the used cooking oils are re-processed into biofuel (a commodity) before being combusted. In contrast, incineration typically burns a large assortment of loosely segregated combustibles.
Environmental impacts of waste cooking oils
Improper disposal of used cooking oil (UCO) has significant environmental consequences, affecting wildlife, water quality, soil contamination, and infrastructure. Here is a summary of the effects:
Wildlife
Waste cooking oil that is left inappropriately stored or illegally dumped can have serious consequences on wildlife.
For animals it can coat feathers or fur, reducing insulation and buoyancy, leading to hypothermia or drowning.
In waterways, waste cooking oil will form a film on the water’s surface, blocking oxygen exchange and harming aquatic life.
Sewer blockages
When cooking oil is poured down drains (a practice that remains a global issue), it can solidify and combine with other sewer waste, forming large blockages known as fatbergs. These can cause sewage overflows and expensive repairs within business premises and the public sewerage network.
💡 Case study: The 2017 Whitechapel fatberg
A massive fatberg, measuring 250 meters (820 feet) long and weighing over 130 tonnes, was discovered clogging the sewers of Whitechapel, London. It consisted of congealed fat from used cooking oil, congealed with wet wipes and other waste materials. Removing it required 24/7 operations for several months and cost about £1 million per month, and this shows why environmental agencies are cracking down on the improper disposal of used cooking oils.
Like other fatbergs in the UK, the Whitechapel fatberg was used to produce biodiesel.
Recommended reading: Environmental impacts of commercial waste
Waste cooking oil management costs for businesses
There are a few direct and indirect costs of properly managing your waste cooking oil:
Cooking oil waste collection costs
Businesses must legally have their waste cooking oil collected by licensed carriers. These companies charge a fee for this service, which typically includes the provision of bins and all the necessary documentation. The fee will depend on:
- Your business location: How far does the carrier need to travel for collection or whether it lies within an established route?
- Volumes: How much waste cooking oil your business generates, as it determines bin and collection vehicle sizes.
- Collection Frequency: How many times per month or week must they come to collect your waste oil?
Check out our full guide to commercial waste collection costs.
Turning a profit (for larger businesses)
This is the hottest tip we could probably give you. If your business makes the extra effort to separate its purest waste cooking oils from the dirtiest, most contaminated ones, it could produce Used Cooking Oil (UCO).
Unlike typical waste oil, UCO can be directly used by biofuel producers, and if you produce large enough volumes regularly, they will pay you for its collection!
However, you must be very careful, as UCO collection companies will reject it if it lies outside a purity threshold. Typically, moisture, impurities and free fatty acids must be present in minimal amounts, less than 2% and 10%, respectively.
Waste cooking oil disposal – FAQs
Our business waste experts answer commonly asked questions on waste cooking oil disposal in the UK.
Can used cooking oil be used to produce animal feed?
Used cooking oil (UCO) has been illegal in the UK as an ingredient in animal feed since 2004, when the Animal By-Products Regulation EC 1774/2002 came into effect. This regulation aims to protect both animal and human health from the risks associated with its use in animal feed, namely chemical contamination, microbial risks and potential toxicity.
Can waste cooking oil be composted?
While cooking oils are technically organic and will eventually degrade into a useful soil amendment, composting them at industrial quantities will disrupt the balance of a compost heap.
Oils can create odours, attract pests, and slow composting by reducing aeration. Small amounts of vegetable oil (like those typically found in food waste) can be composted if mixed well and spread thinly, but avoiding adding cooking oils directly to compost bins is best
See our recycling section for other more suitable alternatives.