How to Store Used Oil?

Properly storing used oil is crucial for safety and preventing spoilage. The best method depends on the type of oil and your intended use.

Storing Used Cooking Oil

For used cooking oil, especially frying oil, follow these steps:

Strain the oil: Use a fine-meshed sieve lined with cheesecloth to remove food particles. This extends the oil's lifespan and improves its quality. (Bon Appétit)
Choose a container: Select a sealed, light-proof container. Avoid using containers that previously held other substances, like milk jugs or coolant containers, as residues can contaminate the oil. (BobIsTheOilGuy) Empty oil containers or clean, airtight food-safe containers are ideal.
Store in a cool, dark place: A cool, dark environment prevents oxidation and rancidity. Storing it in the refrigerator is recommended for longer storage and better quality if you intend to reuse it. (Reddit, USDA)
Check for spoilage: Inspect the oil regularly. Discard it if it becomes cloudy, foams, or develops an unpleasant odor or taste. (Various Sources) Store used frying oil for up to 3 months. (Various Sources)

For used motor oil, regulations are stricter:

Use appropriate containers: Use only designated containers for used motor oil, clearly labeled as "Used Oil." (EPA)
Maintain container integrity: Ensure containers are in good condition, without rust, leaks, or other structural defects. (EPA)
Dispose properly: Used motor oil should be disposed of according to local regulations. Do not pour it down the drain or into the garbage.

For artists' used oil paints, preservation is key:

Protect from air: Store used oil paints on a glass plate, covered, in a freezer to prevent drying. (My Sketch Journal)

Important Note: Always check local regulations for proper disposal of used oil.