Kitchens, both home and commercial, often generate a lot of used cooking oil. Disposing of it properly can be challenging. A simple and eco-friendly solution is converting it into multipurpose soap. The process, called saponification, involves using cooking oil, coconut oil, water, and sodium hydroxide (NaOH). The resulting soap can be used for washing hands, cleaning dishes, washing clothes, and more, offering an environmentally responsible way to reuse waste oil.