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Wash your hands! + ward ' s science Recommended Grade Level(s): Appropriate for: K–8th Grade Time Requirements: Prep Time: 5 minutes Activity Time: 5 minutes Teaching Topics & Concepts: This activity will provide your students with visual evidence that handwashing is the best way to reduce germs. Materials: • Bread • Ziploc bags • Gloves • Hand Sanitizer • Water (ideally sterile water) Safety • Beware of students touching their eyes after applying hand sanitizer. • Water should be warm (but not hot) when washing. • Though the mold that grows on your bread is harmless and already present in the environment, it is still best not to inhale mold spores in a concentrated form. At the end of the growth period, completely seal the Ziploc bags before allowing the students to handle them to perform their observations. • Students with a penicillin allergy can participate in the setup of the experiment, but should not participate in the data collection after incubation. ! Procedure: 1. Label at least 1 clean, unused Ziploc bag for each of the test conditions below. "Gloved Hands" • Apply gloves. Remove a piece of bread from the bag and place it into the corresponding Ziploc bag. 2. "Bare Hands-Hand Sanitizer" • Roll up sleeves. Apply hand sanitizer and allow to dry. Using bare, sanitized hands, remove a piece of bread from the bag and place it into the corresponding Ziploc bag. 3. "Bare Hands-Unwashed" • Using bare hands that have not been washed, remove a piece of bread from the bag and place it into the corresponding Ziploc bag. 4. "Bare Hands-Soap/Water" • Roll up sleeves and wash hands thoroughly with soap and warm water. – Scrub and lather for the entire time while singing the alphabet song. 5. (Mostly) Seal the bags • You'll need to allow for air exchange for the mold to grow. Only zip about ¾ of the zipper. Leave it un-zipped, but do not leave it gaping open. • Place bags in a dark, warm spot where they will not be disturbed for at least 10 days. Record the changes you see day-to-day.