Sunscreen soap and UV radiation
The hypothesis that higher concentrations of Octyl salicylate in a soap mixture would result in greater blockage of UV radiation, has been proven to be true.
The use of sunscreens will block the UV-B and prevents sunburn but it may not necessarily be able to block the UV-A radiation. People who use sunscreen regularly risk overexposure to UV-A and increase their chance of getting a kind of skin cancer called melanoma. Moreover, using the sunscreen too often can also result in vitamin D deficiency.
Would the results of our science fair project differ if it were to be repeated using different types of sunscreen chemicals like oxybenzone or zinc dioxide?
The science project experiment can be also repeated using a UV lamp and performing the experiment indoors, for a more regulated amount of UV radiation.
Sunscreen - http://en.wikipedia.org/wiki/Sunscreen
Octyl salicylate - http://en.wikipedia.org/wiki/Octyl_salicylate
Why measure UV? - http://www.solatell.com/Why%20measure%20UV.htm
How to measure the UV index using the UV meter? - http://www.bom.gov.au/info/weatherkit/section2/pdf/uv.pdf
Avoid long, unprotected exposure to the sun. Handle glass extremely carefully. Adult assistance required.