How to Dispose of Cooking Oil
Everyone has to eat, whether that means preparing our own meals or going to places where someone serves us. And in many cultures and styles of cooking, food preparation includes frying in oil. The relative health of this method is the subject for another discussion. We’re just acknowledging that many people enjoy fried food, that frying all this food requires an enormous amount of cooking oil, and that adding used cooking oil to our waste stream presents some challenges. So how can we properly dispose of cooking oil?
What do we mean by cooking oil?
The oils that most Americans use in preparing food are derived from plants: olive, peanut, palm (tree or kernel), corn, coconut, vegetable (a blend of various refined oils), canola, soybean, cottonseed, grapeseed, avocado, sunflower seed, sesame (raw), hempseed, flaxseed, and toasted seed/nut oils (such as sesame, walnut, and pistachio). Some of these oils can’t tolerate heat at all, while others have a smoke point low enough to make them impractical for high-heat recipes. Some are also just too costly for pouring into a fryer. For the most commonly used oils in the U.S., a quick web search shows what the giant fast food chains are using to fry our food: vegetable, canola, corn, soybean, and cottonseed. (For large-scale use, all of these are blended with natural and chemical additives that you’d be unlikely to have in your home kitchen.)
Organic Authority reports that animal fats are making a comeback as well, and while small amounts of organic lard, beef tallow, chicken fat, and milk-based fats may be healthier than once feared, the American diet still tends overwhelmingly toward fry oils derived from plants.
Why is discarding cooking oil a problem?
There are a few reasons for being mindful about how we discard our used cooking oil. The San Francisco Bay Area’s East Bay Municipal Utility District (EBMUD) offers helpful FAQs from which we learn the following:
- Any kind of grease poured down a drain contributes to a non-water-soluble buildup that will eventually clog home waste pipes or public sewer systems, leading to overflows that may cause health and environmental hazards.
- Hot water, detergents, and in-sink garbage disposals won’t prevent the grease poured into a drain from clotting somewhere down the line.
- Grease poured into or leaked inside a trash can attract rodents and insects, impair the efficiency of garbage trucks, and create messes and hazards at solid waste disposal sites.
EBMUD also reminds us that, while used cooking oil can be recycled (see below), mixing it with used motor oil will just create a useless, toxic mess. Food waste and automotive waste should never be combined.
How can I dispose of cooking oil?
- Cool the cooking oil before you handle it. It’s much easier and safer to work with. (Remember that in medieval times, people defended their buildings and walls by pouring hot oil on the invaders!)
- If you prefer to deal with solid rather than liquid waste, put the oil in your freezer.
- Pour or scoop the cooled or frozen oil into a non-breakable container with a lid that you can seal.
- A plastic bag might seem like an acceptable alternative for getting this stuff out of your house, but depending on how your trash is handled, a broken bag of oil could make for messy problems somewhere down the waste stream.
- Another way of turning oil into solid waste is by mixing it with an absorbent substance like flour, sawdust, or cat litter. Your waste hauler would probably appreciate your putting this mixture into a sealed container.
- After pouring out the oil, wipe down your cookware with a rag before washing. (If you’re tempted to use a disposable towel, read our blog about How to Stop Using Paper Towels.)
Where can I dispose of cooking oil in the San Francisco Bay Area?
The good news about disposing of used cooking oil is that you can probably find a number of businesses in your area willing to accept it. Please note, however, that the following locations are mostly for residential users. If you operate a restaurant that generates gallons of used fry oil, your best bet would be contacting a grease-hauling service.
Outside the San Francisco Bay Area
For locations of cooking oil disposal sites near you, please consult earth911.com, a nationwide search engine for recycling centers. Just click “Where To Recycle” in the top nav bar, and then enter “cooking oil” and your zip code to find the drop-off locations closest to you. earth911.com can find recycling centers for many household items.
Can I reuse cooking oil?
With something as messy as oil, there’s an understandable temptation to get rid of it ASAP. But as a green citizen, you might consider options for reusing your cooking oil.
Cook with it again!
With a bit of kitchen craft and common sense, you can use the same batch of cooking oil for a few more meals. LIVESTRONG.com offers a guide to do’s and don’ts, including best practices for temperatures, ingredients, straining, and storage. Some of this will enhance your food’s taste and nutrition, while some of it is critical for minimizing the risk of cancer and food poisoning.
Make your own soap.
Since oil or fat is a critical component for making soap, just filter the impurities out of your used cooking oil, and you’re ready to get started. Instructables.com shows the basics of soap making through a simple classroom experiment.
If you want to get deeper into the process, here are a number of good resources: https://amzn.to/2Of3Iou
Compost your cooking oil.
Is it okay to put used cooking oil in your compost? Gardening Know How says yes, as long as it isn’t animal fat or plant-based oil that was used for frying animal products. These things will turn your backyard compost into scavenger central for rats, raccoons, skunks, and other unwanted guests. Plant-based oils are acceptable in very small amounts, since too much oil will create water-resistant barriers around everything it touches, reducing the airflow and moisture needed for efficient, stench-free composting.
Use it as nontoxic herbicide and pesticide.
While you don’t want to inhibit airflow and moisture in the compost bin, these properties of cooking oil make it effective for killing weeds and insects. The best way to control and concentrate the dosage is with a spray bottle. When getting rid of insects on plants that you care about, spray lightly on cooler, less humid days and never in direct sunlight.
Cooking oil as biofuel?
Yes, you really can run an internal combustion engine on vegetable oil. The idea has been around ever since Rudolph Diesel demonstrated a peanut-oil-powered engine at the 1900 Paris Exposition. Even though diesel engines were later adapted for petroleum-based fuel, it’s surprisingly easy to convert an antique Mercedes-Benz (early 1980s or older) to run on used cooking oil. Inhabitat explains that, while people might wonder who’s making French fries as you drive past, you’ll cut your CO2 emissions by up to 70% and, after your initial investment in a conversion kit and a safe storage setup, you’ll save a lot of money on fuel. Conversion kit prices range from $595-$2000 for cars and $1500-$3000 for trucks. The cooking oil is usually free — most restaurants would rather give it to you than pay a grease hauler.
Take a look at these biofuel conversion kits for ideas about how to proceed: https://amzn.to/2QcO5AN
A word of warning:
If you plan to store a quantity of used cooking oil for any reason, be aware that it’s highly flammable. Keep your containers out of direct heat and sunlight, locate them a safe distance from structures or inside a fire-safe storage container, and learn how to contain and extinguish a grease fire.
While oils and fats aren’t unhealthy in small quantities, many of us would be healthier if we reduced their presence in our diet. But far too many Americans love the flavors that are enhanced by frying, so this category of food won’t go away any time soon. At the very least, let’s be mindful about what’s left in the skillet or the deep fryer once we’re cleaning up after the meal.
Alan Lipton, GreenCitizen’s writer/editor, firmly believes in the company’s mission to make every day Earth Day. His background in educational nonprofits, health literacy podcasts, experiential marketing, and storytelling helps him shape GreenCitizen’s message. Alan also writes fiction and songs, performs music at farmers’ markets and open mics, and battles unwanted vegetation in the yard.