Decide whether the oil needs to be discarded. Oil used for deep-frying can usually be reused several times. Strain it into a clean sealable container. To throw it away, carefully pour it into a strong sealable container, such as an old plastic jar with a lid. Many households save jars for this purpose.
Plastic jars are better than breakable glass ones.
If the amount of oil is small, place the filled, sealed jar in the trash. Take large amounts of cooking oil to the local landfill. Alternatively, recycle large amounts of used cooking oil with the help of a cooperative local restaurant. Most restaurants have used grease bins, whose contents are recycled into consumer products. Ask if you can add your used oil to their grease bin.