Effect of Variation of Cocamide DEA, Activated Carbon, and Addition of Orange Peel Extract on the Characteristics of Liquid Hand Soap from Cooking Oil

Abstract

The reuse of used cooking oil poses health risks, while its disposal contributes to environmental pollution. One sustainable alternative is to utilize used cooking oil as a raw material for the production of hand washing liquid soap. In this study, hand washing liquid soap was formulated using purified used cooking oil. Additional ingredients included cocamide DEA, a surfactant that enhances foam stability, and activated carbon, which improves the soap's cleaning effectiveness. The research involved two main stages: the purification of used cooking oil and the formulation of the liquid soap. The purification process consisted of three steps—removal of spices and impurities, neutralization, and bleaching. The soap-making process involved saponifying the purified oil with a potassium hydroxide (KOH) solution, followed by dilution of the soft soap with distilled water. The final formulation stage included the addition of cocamide DEA and activated carbon. The results demonstrated that the final product met acceptable quality standards, with a suitable pH level, low levels of free alkali and free fatty acids, and satisfactory foam stability and cleaning performance. These findings indicate that liquid hand soap derived from used cooking oil is not only feasible but also represents an eco-friendly alternative for waste oil management and hygiene product development.