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demonstrations:uv_beads_and_sunscreen_test

UV Beads and Sunscreen Test

Materials: ★★★ Requires materials not commonly found in school laboratories
Difficulty: ★★☆ Can be done by science teachers
Safety: ★★☆ Some safety precautions required to perform safely

Categories: Electromagnetic Spectrum and Waves, The Atmosphere, Weather and Climate

Alternative titles: UV Paper and Sunscreen

Summary

This experiment uses UV-sensitive beads or paper to test how well different sunscreens and materials block ultraviolet (UV) radiation. By comparing the color change in treated versus untreated samples, students can evaluate the effectiveness of SPF and UPF protection.

Procedure

  1. Prepare UV-sensitive paper or beads, dividing them into separate transparent bags or sheet protectors.
  2. Label each bag with a test condition, such as “SPF 15 sunscreen,” “SPF 30 sunscreen,” “sunglasses,” or “fabric.” Include one untreated control group.
  3. Apply sunscreens or place materials so that they block the UV light from reaching the beads or paper.
  4. Expose the samples to direct sunlight or a UV lamp for the recommended time (1–10 minutes, depending on the product instructions).
  5. Compare the intensity of color change between conditions and record observations.

Solar Science UV Beads - Cool Science Experiment - SpanglerScienceTV:


Sunscreen Protection Experiment - Summer Science Series - Dr Boyd The Chemist:


📄 UV exposure experiment - Cancer Institute NSW: https://www.cancer.nsw.gov.au/getmedia/e87dd299-0e3b-40c3-880e-71ed7e5c08f9/4-3-4-a-UV-exposure-experiment.pdf

Variations

  • Test different brands or forms of sunscreen (creams, sprays, lip balms, makeup with SPF).
  • Compare different fabrics, such as cotton, polyester, or tightly woven versus loosely woven cloth.
  • Test sunglasses with and without UV protection labels.
  • Use a UV lamp indoors to repeat the test independent of weather.

Safety Precautions

  • Avoid looking directly at UV lamps.
  • Do not apply sunscreen to skin during this test – apply it only to bags or sheet protectors.
  • Dispose of used UV paper as directed by the manufacturer.
  • Work outdoors in shaded intervals to prevent prolonged sun exposure.

Questions to Consider

  • Why do UV beads or paper change color in sunlight but not in indoor light? (Because they react to ultraviolet radiation, which is present in sunlight but mostly filtered out indoors.)
  • Why do some materials block UV light more effectively than others? (Denser, darker, or specially treated materials absorb or reflect more UV radiation.)
  • Does a higher SPF rating always mean better protection? (Generally yes, but proper application and reapplication are also critical for effectiveness.)
  • Why is testing UV protection important in everyday life? (Because UV exposure can damage skin and increase the risk of skin cancer, making effective protection essential.)