The Effect of Different Brands, SPFs, Types of Sunscreens, and the Amount of Sunscreen on how well They Protect Against UV Light

Student: Joyce Xia
Table: 3
Experimentation location: Home
Regulated Research (Form 1c): No
Project continuation (Form 7): No

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Additional Project Information

Project website: -- No project website --
Additional Resources: -- No resources provided --

Research Plan:


Background Research Questions/Topics:

  • What does sunscreen do?/What is  the purpose of sunscreen?

            Sunscreen protects the skin from harmful UV radiation, and minimizes the chances for severe sunburns, skin cancer, and various skin disorders.

  • What is SPF and how does it affect the sunscreen?

            SPF stands for sun protection factor, and is a measure of how much solar energy it will take to penetrate the skin and cause sunburn with sunscreen in comparison to how much solar energy it will take when fully exposed. The higher the SPF, the more protection the sunscreen provides against UV light.

  • What are the types of sunscreen and the differences between them?

            The types of sunscreen are chemical and mineral, which is also commonly referred to as physical. The main difference between the two is how they protect against sunlight. Mineral/physical sunscreen physically sits on the skin and reflects the sun’s rays, acting as a barrier. In contrast to this, chemical sunscreens form a thin layer and are absorbed into the skin. They continue to absorb the UV light the skin is exposed to, and convert them into heat. The different ingredients as well as the different consistencies can help you determine whether a sunscreen is chemical or mineral.

  • What types of materials do chemical sunscreens contain?
    •    Active ingredients in chemical sunscreen are oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate.
  • What types of materials do mineral sunscreens contain?

            Active ingredients in mineral sunscreen are titanium dioxide and zinc oxide.

  • What will be used to find how well the sunscreen protects skin? How do UV sensitive materials work?

            UV sensitive cards will be used to find how well a sunscreen protects the skin. UV sensitive materials are coated in chemicals that will respond when exposed to light waves by changing color. The darker the color, the less protection there is.

  • How will the experiment be conducted and performed?

            Cards will be coated with different sunscreens and taken outside to be exposed to the sunlight. The colors will be recorded in different time increments; instantly, after 10 seconds, 30 seconds, 1 minute, 3 minutes, and 5 minutes. These colors will be evaluated by their RGB values. Due to the fact that the sunscreen cannot be perfectly applied in an even layer, the lightest and the darkest hues on the card will be recorded and averaged.

  • What are RGB values and what do they mean? What are some important rules of RGB values?

            RGB values are a way of color coding different colors. The r stands for red, the g stands for green, and the b stands for blue. The RGB color coding system states that every color is composed of red, green, and blue. The first prominent rule about RGB values is that the larger the numbers are, the lighter the color will be. The second most prominent rule is that when all the values of R, G, and B are equal, the color produced will be neutral (white, black, gray). Lastly, when the values are closer together, they are closer to being neutral. The farther the colors are away from each other, the purer and stronger the color.



  • UV sensitive cards or paper
  • Portable trays
  • A cover for the tray
  • Coppertone Tanning Sunscreen Lotion
  • Neutrogena Ultra Sheer (I had one with 30 SPF, one with 55 SPF, and one with 70 SPF)
  • Neutrogena Sheer Zinc
  • Coppertone Pure & Simple Baby Sunscreen Lotion
  • Ultrasun Professional Protection Face (I had one with 30 SPF and another with 50+ SPF)
  • Skinceuticals Physical Fusion
  • Sun Bum (I had one with 30 SPF, and another with 50 SPF)
  • Lamer UV Protecting Fluid
  • Coppertone Kids Tear Free Sunscreen Lotion
  • Banana Boat Sport Ultra Spray
  • Tatcha Silken Pore Perfecting Sunscreen
  • Device with Apps to determine color (I used Pixel Picker)
  • Device to record and take pictures
  • Device to record time



  • Remember when using substances like sunscreen to keep it away from your eyes and mouth.
  • Try to use portable trays that are very light in order to minimize the risk of dropping items and hurting yourself.



Step 1: Gather all materials for the project.

Step 2: Label all the cards and sunscreens with numbers.

Step 3: Spread a layer of the corresponding sunscreen onto the cards. You can try adding different thicknesses and amounts of sunscreen, but make sure that every type receives the same amount.

Step 3: Place the cards on a portable tray that you will be able to carry outside.

Step 4: Cover the tray with another tray or a cloth. If your tray is completely flat, it will be difficult to cover.

Step 5: Bring the covered tray outside into where the cards will be exposed to the sunlight.

Step 6: Quickly remove what is covering the tray and begin recording the time the cards have been exposed to the sunlight. The cards will begin to change color when exposed to UV rays.

Step 7: Take a picture the instant the cards are exposed.

Step 8: Use a timer and take more pictures of the cards in 10 seconds, 30 seconds, 1 minute, 3 minutes, and 5 minutes. These are the time intervals I used in my experiment, but they are completely able to be altered to your choice.

Step 9: After you are done taking your pictures, cover the tray again and bring it back inside.

Step 10: Wait for the cards to change back to their original color and wash off the excess sunscreen on the cards.

Step 11: Repeat steps 3-9 until you have finished three trials. You can alter step 3 slightly in each trial by adding more sunscreen to the cards if you did not add enough.

Step 12: Evaluate the colors of the cards in Pixel Picker, or another app that can determine the color values from an image.

Step 13: Record the lightest hue and the darkest hue on each card. Find the average and compare the differences between the sunscreens.

Step 14: After examining the colors, rate the color on a scale from 1-5, with 1 being the most protective to 5 being the least protective.




Questions and Answers

1. What was the major objective of your project and what was your plan to achieve it? The major objective is to find out the effectiveness of different kinds of sunscreens. Therefore, it can provide a guide for buying different sunscreens. The plan to achieve it is to design experiments to find out.

       a. Was that goal the result of any specific situation, experience, or problem you encountered?  Yes. Because there are so many choices of sunscreens on the market and their prices are very different. It is very hard to make the right choice.

       b. Were you trying to solve a problem, answer a question, or test a hypothesis? I was trying to solve a problem and also test my hypothesis.


2. What were the major tasks you had to perform in order to complete your project? The major task is to design the experiments to test out my hypothesis.

       a. For teams, describe what each member worked on.


3. What is new or novel about your project? The novelty of my project is to use UV light card to mimic the human skin and visualize the UV effect on human skin.

       a. Is there some aspect of your project's objective, or how you achieved it that you haven't done before? I am not sure how well it will work to use the artificial UV cards to mimic human skin. 

       b. Is your project's objective, or the way you implemented it, different from anything you have seen? The experimental results were more complicated than I initially expected. 

       c. If you believe your work to be unique in some way, what research have you done to confirm that it is? The UV cards I got were used to test the strength of UV rays in the sun light to provide a guidance for choosing sunscreens. They were not designed to study the effectiveness of sunscreens. Therefore, my experiments were unique.


4. What was the most challenging part of completing your project? The color changed happened very fast and the color changed were not easy to see from naked eyes. 

      a. What problems did you encounter, and how did you overcome them? The color change speed was very fast for each card. To solve this problem, I had to shorten the exposure time. In addition, the color change was not easy to see from naked eye. To solve the problem, I had found an app tool that can measure the color scientifically. The color was characterized by color coordinates, which can precisely define the color.

      b. What did you learn from overcoming these problems? What I learned is that to think creatively and do more research.


5. If you were going to do this project again, are there any things you would you do differently the next time? It is difficult to determine whether SPF truly matters in an experiment like this, however there are many sources with real, practical scenarios that prove the importance of SPF. There is no distinct difference between how well chemical and mineral sunscreens perform, however mineral sunscreens must be applied more thickly. Some things I would do to improve the experiment would first be to minimize the area for human error and outside factors. The cards I had used are reusable, and revert back to white after it is brought back to an environment without exposure to UV light. If I were to try this experiment again, I would also see how long each sunscreen would take to revert back to normal, or find a way to see how water resistant each sunscreen was. I would also search for a more efficient and accurate way to represent how it would work on actual skin.

6. Did working on this project give you any ideas for other projects? Yes. I have learned a lot of lessons from this project. The experiments may not clearly give the results you expect. It is important to design the experiments well and do thorough preparation before doing experiments.


7. How did COVID-19 affect the completion of your project? No effect.