The Effects of Sunscreen Brand, SPF Rating, and Type on the Penetration of UV-B Radiation
The objective of this experiment was to determine what brand, SPF rating, and type (chemical or physical) of sunscreen lets the least amount of UV-B radiation pass through to the skin. Each sunscreen (Avon SPF 8, 15, and 30; Banana Boat SPF 8; Coppertone SPF 8; Target SPF 45; and zinc oxide) was spread thinly on an index card covered in plastic wrap over a hole in the card. The cards were placed into a black light box above a UV-B sensor for two minutes while a UV light bulb emitted rays. The UV reading was measured using the UV-B sensor and a Vernier LabQuest. Seven two-sample t-tests were run to find out if the amount of UV-B (mW/m2) that passed through each sunscreen was significantly different from the amount that passed through the other sunscreens. All of the t-tests showed that the amount of UV-B passing through was significantly different except for Avon SPF 8 vs. Coppertone SPF 8, which means that they allowed approximately the same amount of UV-B radiation through. Other than the Avon SPF 8 vs. Coppertone SPF 8, the amount of UV-B passing through was significantly different because the t-tests had a p-value less than 0.05. This means that there is almost no chance that the amount of UV-B rays that passed through one sunscreen was the same as the amount of UV-B rays that passed through another sunscreen.
Research Done By:
Mandie Buchowski
Sterling Heights High School
Melissa Zuteck
Sterling Heights High School
Warren Consolidated Schools