When it has expired, there are a couple of things you can do. First and foremost, you should dispose of it properly. After expiration, the oil can become rancid, leading it to create off-putting flavors and smells when used in cooking or baking.  Here are some creative ways to use expired oil: 1. Rust-proof survival gears. 2. Remove rust. 3. Make emergency fuel (biodiesel). 4. Lubricate a chainsaw. 5. Lubricate squeaky joints. 6. Protect your gardening tools. 7. Create light. 8. Keep pests away. (Reference: 10 Surprising Emergency Uses for Expired Cooking Oil)