UV filter in a bottle

Students test how sunscreen lotion blocks UV radiation using light-sensitive colour-changing beads.

Steps

1. Conversation: what the ozone layer is and what natural and chemical factors deplete it.
2. Students observe photochromic UV beads in classroom shade (white) versus outdoor sunlight (vibrant colours).
3. They spread sunscreen with high SPF across transparent cling wrap and wrap a bundle of beads.
4. They compare colour intensity of beads wrapped in sunscreen film versus unprotected beads.
5. Key takeaway: how atmospheric ozone protects Earth and how we protect our skin.

Tip: Photochromic UV beads are inexpensive and can be reused for World Health Day activities.

Materials needed

• colour-changing UV beads (1 pack)
• Plastic cling wrap (1 roll)