September 13, 2013
Period 7
UV Lab
Purpose:
What sunscreen protects the most using UV sensitive beads?
Background Research:
I used UV sensitive beads to test how effective sunscreens are. The UV sensitive beads can be used because it contains different pigments that change color when exposed to ultraviolet light from any source. In this experiment I used sunlight. The beads are all white but in UV light they will change colors. The beads can change colors about 50,000 times before the pigment will no longer respond to UV light and it will not work.
SPF is the sun protection factor. It measures how well a sunscreen will protect skin from UVB rays which cause sunburn, damage skin, and contribute to skin cancer. If you take the time it takes your skin to burn and multiply it by the SPF, it would give you the amount of minutes the sunscreen is going to protect you from burning. It depends on your skin type, intensity of sunlight, amount of screen used and activities you do.
UV radiation is part of the light that reaches the earth from the sun. It has wavelengths shorter than visible light, making it invisible to the naked eye. These wavelengths are UVA, UVB, or UVC. UVA is the longest. UVB ranges from 290-320 nm. UVC has shorter rays and most of them are absorb by the ozone layer and does not reach the earth. UVA and UVB penetrate the atmosphere and cause premature skin ageing, aye damage, and skin cancers.
Both sunscreens had almost the same chemicals such as oxybenzone. The use of this chemical has been approved by the FDA and government agencies in Canada and the EU. They say it’s a safe and effective sunscreen ingredient. Vobenzone is another chemical in the sunscreen that absorbs the full spectrum of UVA rays. Octisalate has a good safety profile. Lastly, octinoxate is shown to have hormone-mimicking effects on laboratory animals. This chemical is found in humans, including mother’s milk samples.
Hypothesis:
If the 2