Sustainable Solutions for Used Cooking Oil

Rothsay offers used cooking oil collection (UCO) and grease trap services to Canadian restaurants, supermarkets and others in the hospitality industry. These FAQs focus on used cooking oil in a general sense - how is used cooking oil used, how to dispose of used cooking oil safely, what to do with your home cooking oil, and recycling your Thanksgiving turkey grease. For more information on our UCO services and how we collect used cooking oil from our customers, see our Restaurant FAQs.

How much used cooking oil is generated in a year?

According to the National Renderers Association, approximately 4.4 billion pounds of used cooking oil is collected annually from restaurants, grocers, hotels and casinos, and other foodservice providers in Canada and the US.

How do I dispose of used cooking oil?

Whether you are a homeowner or a business owner, used cooking oil should never be disposed of down the drain, as it can clog pipes causing problems that can be costly to fix. Overflows from clogged pipes can also result in fines for business owners who incorrectly dispose of their grease. Businesses should contact a reputable service provider to provide collection bins or tanks and who will pick up your used oil on a regular basis.

What happens to my used cooking oil after it’s picked up from my store?

After our service tech has removed the used cooking oil from your store, we take it to one of our processing facilities. There it is put through strainers to remove contaminants (grill bits and debris), heated to remove water and kill off any pathogens, and marketed as a commodity whose value is tracked and published daily. Most of the processed cooking oil our company collects in Canada and the U.S. is used to produce biofuel.

What can you do with used cooking oil?

Almost all of the used cooking oil our company collects from restaurants, supermarkets and other foodservice establishments is used to produce biofuel. The demand for sustainable fuel is high, and used cooking oil is an inexpensive, sustainable feedstock. The used cooking oil is dewatered and cleaned at our processing facilities, and produced into biodiesel (Darling Ingredients owns two biodiesel plants: our Rothsay facility in Ste. Catherine, Quebec and another facility Butler, Kentucky) or into renewable diesel (we co-own a renewable diesel refinery with Valero Energy in Louisiana).  A co-product of the biodiesel production is glycerin, which can be used in numerous applications including hand sanitizer, cleansers, lotions, solvents, and much more; co-products of renewable diesel production are renewable propane, renewable butane, and renewable naphtha, which is used in solvents, paint thinners, varnish, plastics and more.

Processed used cooking oil can also be used as a nutritional supplement for animal feed and in the production of numerous common household and commercial products.

  • Pie charts on how cooking oil and fats are used

How do homeowners dispose of their kitchen grease?

NEVER pour used grease down your kitchen drain unless you like to personally support the local plumbers. If the used grease is strained and stored in a cool place, it can safely be reused a few times. Once the oil is spent, contact your city; many offer used cooking oil drop-off points, particularly during the holidays. If no drop-off is available, put the used oil in a disposable container and discard in your trash.

How can you recycle used cooking oil at home?

We are limited on what we can do with our used grease at home. Virtually the only 'recycling' available to us is to save the used grease in a clean can, in a cool place, for later re-use when frying potatoes or meats.  If stored properly, the grease can be re-used a few times before the nose-test says it's time to dispose of it.  To discard, secure it in a closed container and place it in the trash.  For larger amounts, like a fried holiday turkey, contact your local city or fire department; they often have grease days for residents to turn in their used grease for recycling. If you have a compost pile, you can add small amounts of grease at a time. Too much could be a problem. See our next answer below.

Can I put used cooking oil in my compost pile?

Avoid adding used cooking oil to your compost pile; small amounts may not be problematic, but too much can emit an unpleasant odor attracting rodents and animals and can encourage pathogens. Too much grease can also slow down or even halt the compost action.

Will you pick up my turkey grease?

We are not able to collect used cooking oils from homes. To adhere to sourcing and tracking requirements of the materials we use in the fats, oils, proteins and greases we produce, our company can only collect from contracted customers. Check with your city or local firefighters. During the holidays, there are often special drop-off spots for the grease that deep fried that yummy turkey your family and friends enjoyed.

Do you recycle motor oil?

No, we only recycled used cooking oils from businesses, industrial, institutional and commercial establishments. If you have motor oil to discard, contact your city or local automotive retailer and ask if they have drop off locations. Many cities offer periodic hazardous waste collection days; store your old motor oil safely and drop it off at those events. Motor oil contains chemicals that could be dangerous to groundwater, vegetation, or water supplies, so should never be poured onto the ground or down a drain.