How to deal with expired edible oil

Expired edible oil is not recommended for continued consumption, but it can be disposed of through recycling, making handmade soap, and using as a lubricant. Expired edible oil may produce harmful substances, and direct disposal may pollute the environment. Expired edible oil is prone to oxidation and rancidity at high temperatures, producing harmful compounds such as aldehydes and ketones. Long term intake may increase the burden on the liver. Sour and rancid fats can destroy vitamins in food and reduce its nutritional value. A small amount of expired oil can be used at home to lubricate door hinges, bicycle chains, or mixed with sawdust as a combustion enhancer. If there is a biodiesel recycling point in the community, it can be handed over to a professional organization for disposal to avoid direct discharge into the sewer causing pipeline blockage and water pollution.

Some catering institutions will collect expired oil for industrial use and need to contact local qualified processing units. When making homemade soap, it is necessary to filter the expired oil and mix it with sodium hydroxide in proportion. This process has a certain degree of corrosiveness, so protective gloves should be worn during operation. If plant-based oils have a rancid taste or darkened color after expiration, it indicates a high degree of oxidation, and even high-temperature heating is difficult to eliminate harmful components. After expiration, animal fats are more prone to bacterial growth and are not recommended for secondary use.

In daily life, edible oil should be avoided from long-term exposure to light and high temperature environments, and should be used up within 3 months after opening. Choose small packaging when purchasing and store according to household usage. Regularly check the condition of the oil and replace it promptly if any odor or sediment is found. Waste oil can be adsorbed with newspapers or coffee grounds before treatment to reduce flow pollution. Environmental protection departments usually have designated recycling stations, and some cities provide door-to-door recycling services to properly dispose of expired oil, ensuring both health and protecting the ecological environment.