• Researchers: Marcia Halim, Queen Wijaya, Ray Widjaya, and Phonlaphat Waechawatchana
  • Level/Campus: Primary 4 - Semarang
  • Abstract: This project investigates the effectiveness of a natural lemon spray as an alternative to commercial chemical cleaners. Made from lemon peels, vinegar, salt, and water, three samples were tested over different extraction periods (7, 14, and 21 days). Tests on cleaning power, surface safety, and pH showed that Sample 1 (7-day extraction) performed best, maintaining cleaning effectiveness and safety with no surface damage. The spray remained mildly acidic (pH 4), ideal for stain removal and odor control. This natural cleaner supports sustainable practices and offers an affordable, eco-friendly solution that is most effective when used within the first week.
  • Coach: Ms Hana Vetriana