Determining the Effectiveness of Store-bought and Homemade Sunscreen
Sunscreen is the main source of protection people use against the sun. The United States Department of Health and Human Services and the World Health Organization's International Agency of Research on Cancer panel have declared ultraviolet (UV) radiation from the sun to be a known carcinogen (cancer-causing substance). The purpose of this experiment was to determine if a homemade physical sunscreen (zinc oxide, almond oil, beeswax) SPF 15 can be as effective as Badger Physical Sunscreen SPF 15.
Physical sunscreen protects people from dangerous UV rays by reflecting UV rays due to its main ingredient: zinc oxide. It was then hypothesized that the homemade physical sunscreen would work as well as the store-bought sunscreen, due to the fact that they both had the same active ingredient. To test the hypothesis, the net change in UVA/UVB rays (mW/m2) was evaluated with the control as the full spectrum light bulb lit up through the hole in the card. There was 0.1 g of homemade and store-bought sunscreen spread onto the index card, and the net UVA/UVB (mW/m2) was taken after the treatment and then used to execute two two-sample t tests. Each t test resulted in a p-value more than the alpha level of 0.05, meaning that the sunscreens did not yield significantly higher changes in UVA or UVB intensity, supporting the hypothesis that homemade sunscreen was as powerful as store-bought sunscreen.
Research Conducted By:
Rogina Hanna
Warren Mott High School
Lara Thomas
Sterling Heights High School
Warren Consolidated Schools