Presentation on theme: "An Analysis of the Protection of Different SPF Levels in Sunscreen Becca Gleeson Grade 9."— Presentation transcript:
An Analysis of the Protection of Different SPF Levels in Sunscreen Becca Gleeson Grade 9
Problem Is there a limit to the maximum amount of protection you can get from UV radiation by increasing the SPF of sunscreen? My experimentation could help fair skinned people decide whether it is beneficial to buy a high SPF of sunscreen.
Research There are three different types of ultraviolet (UV) radiation from the sun: UVA, UVB, and UVC. UVA and UVB radiation can cause skin cancer. Broad Spectrum sunscreens are designed to block UVA and UVB rays. The UV lamps that were used radiated UVA and UVB rays. UV Fastcheck Strips® measure the energy absorbed from the entire UV spectrum of radiation.
Research SPF stands for Sun Protection Factor. The SPF number multiplied by the time it typically take a person to burn equals the length of time it takes to receive the same UV exposure as if no sunscreen was used. As the SPF increases, the amount of additional protection gained decreases.
Hypothesis H 0 : There will not be a statistically significant difference between the amount of protection provided by the different SPFs of sunscreen. H A : There will be a statistically significant difference between the amount of protection provided by the different SPFs of sunscreen. If the UV protection provided by sunscreens of SPF 15, 30 and 50 is measured, then there will not be a statistically significant difference between the amount of energy absorbed when using SPF 30 or SPF 50.
Procedure The UV lamps were set up at a set distance from where the strips were to be laid. Three of the UV Fastcheck Strips® were laid under the lamps. The sunscreen was added to two microscope slides (except for when testing the control trials). One glass microscope slide was placed on top of two of the UV Fastcheck Strips®. The other microscope slide was placed on top of the other strip. The lamps were turned on. A timer was set for 900 seconds. The strips were checked every 900 seconds for a total of 5,400 seconds. When checked, the color of the strips was compared against the Comparative Dose Chart. All of the steps were repeated for each SPF and the control.
Procedure Steps for adding sunscreen: The glass microscope slide was placed on an electronic balance. The electronic balance was zeroed. A one tenth gram of SPF 15 sunscreen was added. All of these steps were repeated for the second slide. All of the steps above were repeated for the SPF 30 and 50 sunscreen trials.
Variables Independent variable: The SPF of Sunscreen Dependant variable: The amount of millijoules of UV radiation absorbed by the UV Fastcheck Strips® Control: The three trials without any sunscreen Constants: The UV lamps power, the amount of sunscreen used, the brand and type of sunscreen, the distance from the lamp, the glass microscope slides, the time tested, the UV Fastcheck Strips® and Comparative Dose Chart
Time (seconds)Trial 1Trial 2Trial 3Average Standard Deviation Data Amount of UV Radiation Absorbed (mJ per cm 2 ) Control Time (seconds)Trial 1Trial 2Trial 3Average Standard Deviation Amount of UV Radiation Absorbed (mJ per cm 2 ) SPF 15
Data Time (seconds)Trial 1Trial 2Trial 3Average Standard Deviation Time (seconds)Trial 1Trial 2Trial 3Average Standard Deviation Amount of UV Radiation Absorbed (mJ per cm 2 ) SPF 50 Amount of UV Radiation Absorbed (mJ per cm 2 ) SPF 30
Control AverageSPF 15 AverageSPF 30 AverageSPF 50 Average y = 0.014x y = x y = x y = x R² = R² = R² = 0.99R² =
Conclusion Hypothesis was supported. There was a significant difference between the control and SPF 15 compared to SPF 30 and 50. There was not a significant difference between the protection given by SPF 30 and 50. This shows that after a certain SPF, the protection provided does not significantly differ. Further experimentation could include testing for longer periods of time or with higher SPFs of sunscreen. Sources of Error may include the position of the lamps and not checking the strips at exactly the right time.
Thank You! Thank you for listening to my experiment and presentation! At this time, I would like to invite any questions about my experiment.
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