Used cooking oil is often carelessly discarded by the community, which can pollute the environment and endanger health. Addressing this issue, the community service team from the Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Semarang (UNNES), held an activity themed “Used Cooking Oil Becomes a Blessing” in RW 05, Pakintelan Village, Gunungpati District, Semarang City, on Sunday, May 25, 2025.
This activity aimed to raise environmental awareness while empowering the community through the utilization of household waste. Around 30 housewives from RW 05 Pakintelan participated in the training. They were taught how to process used cooking oil into useful and economically valuable products such as dishwashing soap, aromatherapy candles, and eco-friendly briquettes.
The FMIPA UNNES community service team consisted of lecturers and students from the Chemistry and Physics groups. The activity was chaired by Dr. Nuni Widiarti, S.Pd., M.Si., with lecturer members Dr. Triastuti Sulistyaningsih, M.Si., Dr. Budi Astuti, M.Sc., and Devy Lestari, S.Pd., M.Pd. Meanwhile, the student team consisted of Roja Maysa Rohamh, Nala Izzul Muna, and Amanda Farizka Maylani.
The program began with remarks from the head of RW 05 Pakintelan, who expressed appreciation for the implementation of this educational initiative. He emphasized that processing used cooking oil into soap, aromatherapy candles, and briquettes not only reduces environmental pollution but also creates new business opportunities for housewives.
The first material presented was the recycling process of used cooking oil. The oil needs to be left for 1-2 days to allow impurities to settle, then filtered using a fine cloth or filter paper to remove residue. After this, the oil is ready to be used as a base material for other products.
The second session focused on making aromatherapy candles. The ingredients included 250 ml of clean used cooking oil, 200 grams of paraffin, fragrance of choice, a cotton wick, and candle molds made from glass, used cans, or eggshells. The process began by melting paraffin over low heat, then mixing in used cooking oil and fragrance while stirring gently. The mixture was poured into molds with a wick and left to harden.
The third session explained how to make dishwashing soap. The ingredients were 1 liter of clean used cooking oil, 130-150 grams of caustic soda (NaOH), 300 ml of water, essential oils, natural dyes, and soap molds. The process began by dissolving NaOH in water (which produces heat and must be cooled to 40°C), then mixing it with the oil for 30 minutes while stirring. Essential oils and dyes were then added, and the mixture was poured into molds. The soap was left for 2-3 days, then cured for 3-4 weeks until its pH was safe for use.
The fourth session covered making eco-friendly briquettes. The materials included 1 kg of sawdust or rice husk charcoal, 100 ml of used cooking oil, 100 grams of starch, sufficient water, and briquette molds. All ingredients were mixed until sticky, then molded and sun-dried for 2-3 days until ready to use as an alternative fuel.
After the presentations, the RW 05 residents had a hands-on practice session in making aromatherapy candles, soap, and briquettes, guided by the UNNES team. The training atmosphere was interactive, with participants showing great enthusiasm. Some even expressed their intention to continue independent production.
This activity brought tangible positive impacts. First, it increased residents’ knowledge in managing household waste to prevent environmental pollution. Second, it opened new business opportunities for housewives through soap, aromatherapy candle, and briquette products. Third, it contributed to environmental protection and climate action by reducing pollution from the careless disposal of used cooking oil.
The “Used Cooking Oil Becomes a Blessing” program also supports the targets of the Sustainable Development Goals (SDGs), particularly in climate action, waste management, and community empowerment. With the commitment of residents to continue processing used cooking oil independently, this activity carries sustainability aspects and the potential for business development that can improve family welfare while preserving the environment.
