Eco-Friendly Ways to Dispose of Oil

Medically Reviewed by Dany Paul Baby, MD on November 03, 2022
5 min read

Cooking oil is something that we use regularly in the kitchen, but this common ingredient may not be as harmless as it looks. If not handled well, used oil can be dangerous to both your home and the environment. 

Read on to learn more about cooking oil's environmental impact and its eco-friendly disposal, how to recycle cooking oil, and more.

Disposing of fats, oils, and grease properly is a serious matter. Fats, oils, and grease are together termed FOG, a category that includes cooking oils, animal fats, shortening, lard, gravies, sauces like mayonnaise, soups, butter, food scraps, and ice cream. FOG may be solid, semi-solid (viscous), or liquid in consistency.

Unfortunately, animal fat, vegetable oils, and petroleum oils are all harmful to the environment in various ways. These include:

  • Turning into toxic products
  • Forming products that don’t decompose easily and pollute the environment for years
  • Corroding concrete and metals and polluting the groundwater
  • Contaminating current and future sources of water and food for wild and domestic animals 
  • Coating aquatic plants and animals in oil, causing them to die of suffocation due to oxygen depletion
  • Coating wildlife in oil, causing them to die of starvation, hypothermia, diarrhea, and dehydration
  • Blocking pipes and sewers, causing backups, leaks, and overflows of contaminated water
  • Contaminating seashores and water treatment plants, becoming a fire hazard due to the flammable oils

Cooking oil needs to be managed and disposed of carefully and responsibly to safeguard the environment.

Yes, cooking oil can be recycled and reused in many ways. 

If you’d like to reuse it for cooking, cool it down, strain it with a coarse cloth, store it in a glass jar, and tightly seal the container. 

That being said, you can only reuse oil a finite number of times. The number of times will vary. For example, you shouldn’t use leftover oil from a batter-fried dish more than 3 to 4 times, but you can reuse the clearer oil from frying potato chips up to 8 times. 

You can also use old oil to make weed killers or insecticides for your garden by mixing it with soap. 

If you have large quantities of oil to recycle (e.g., if you work at a restaurant), then you could ultrafilter the oil to use as a fuel directly or use a chemical conversion process to produce biodiesel from cooking oils like soybean oil. 

FOG is also used as a raw material for the petroleum industry to produce fertilizers, feedstock, and other household products like soaps and cosmetics.

There are many environmental benefits that come with recycling used oil:

  1. You can protect the soil and water from being contaminated by residual oil.
  2. You can repurpose a valuable source and prevent waste while also minimizing pollution.
  3. Compared with crude oil, a much smaller amount of used oil is required to produce the same quantity of repurposed oil (for example, if you want to produce 2.5 quarts of lubricating oil, you’d need 42 gallons of crude oil but only 1 gallon of used motor oil).

Thus, recycling is a safe, efficient, environment-friendly, and economical method for handling used oil.

Cooking entire meals can often be exhausting, and it can be tempting to rush through the cleanup, pouring the leftover oil into the sink and being done with it. Unfortunately, the residual oil will not only clog up your kitchen pipes but also contaminate the entire sewage system.

The safety of your home and environment is in your hands. Here are some basic methods to use, disposing of FOG in an environmentally friendly manner:

  • Always let the oil cool before throwing it out.
  • Pour the oil into a separate disposable container before getting rid of it. You could use old plastic bottles, empty milk cartons, or takeout containers.
  • Ensure that the disposable container is properly sealable so that the oil doesn’t spill out into the remaining garbage once it has been packed.
  • Once sealed, these containers can be disposed of in the household trash bin.
  • Oil requires around a day to completely solidify. Consider freezing the oil into solid form for ease of handling and disposal. 
  • To dispose of large quantities of cooking oil, pour it into the vegetable oil tank at your nearest recycling area.
  • If there’s a hazardous waste disposal at a restaurant, hospital, or company near you, you could opt for a doorstep pick-up service for optimal waste disposal.
  • Manual grease disposal systems containing foil-lined plastic containers are also available for disposing of used oil in an eco-friendly way.
  • Vegetable oils can sometimes be composted.
  • You can mix used cooking oil with waste materials like sand, flour, sawdust, or pet litter, which can soak it up and turn it into solid waste. This can make it easier for you to store and dispose of the oil at your convenience.

Don’t pour used oil down the sink, toilet, or dishwasher. This will only make the oil stick to the sides of the pipes and clog the drains eventually. 

No amount of soap or water can clean it. It will gradually solidify and turn into a gel, producing a foul odor and causing blockages and backups. You may have to spend a lot of money to clean or replace your plumbing.

Also, don’t throw out hot oil in the garbage. This will attract a lot of vermin like bugs and mice. Don’t leave used oil by the curbside or use plastic bags to dispose of used oil, either, as plastic bags aren’t strong enough and are likely to spring leaks, making your garbage flammable.

Cooking oil disposal can be tricky. Unfortunately, taking shortcuts or improper handling of used oil can have serious consequences for the environment. 

On the other hand, you can reuse, recycle, or repurpose used oil, depending on your preference. Try to dispose of oil in a careful and responsible manner so that you don’t add to the ever-increasing global pollution.

You could also consider using less oil in your cooking and opt for alternative cooking methods like steaming, baking, and air frying. This is often not only good for your health but also great for the environment.