Science Models
Science Fair Projects

Its Not About The Money

Published on Sep 16, 2023


The objective: To see if the price of the sunblock is proportional to the effectiveness of the SPF in the product. In the summer do you always wonder what sunblock to use? Well, I can help to see if you are buying the right type of product at a resonable price.


My hypothesis is that the cost of the product will not change the effectiveness of the sunblock. That is, a more expensive product will not be more effective than a less expensive product.


1. 4types of sunblock each with an SPF of 30

2. Banana Boat- $8.49 – 240mL

3. Coppertone- $10.49 – 237mL

4. Ombrelle- $14.27 – 120mL

5. Arbonne - $39.00 – 168mLOIL

6. Case of developing paper

7. 4 clear plastic report folders

8. Distilled water

9. A dish pan

10. Sodium thiosulfate

11. Masking tape

12. Sunny weather

13. A semi-darkened room

Its Not About The Money


For the first part of my project, I bought some distilled water and 4 types of sunblock that had the same SPF of 30. The sunblock’s were Coppertone, Ombrelle, Arbonne, and Banana Boat. The price of each sunblock varied in price and quantity. I then purchased a case of developing paper and 4 clear plastic report folders from a local photography store. A type of chemical called sodium thiosulfate was purchased online.

I used a dish pan from my mom’s kitchen. I then conducted the experiment in the following way: I divided the report folders in 4 equal squares using masking tape. I labeled each sunblock 1, 2, 3, or 4. I did the same thing to each square, and matched the numbers to the correct square, putting sunblock on each square. I dimmed the lights very low, took out a piece of developing paper, making sure to close the case afterwards to keep the light away from the other sheets. I put the glossy-side up of the developing paper in each report, taking it outside for 5 minutes, where it is sunny.

While it was outside, I made the mixture of the sodium thiosulfate and the distilled water in the dish pan. After the 5 minutes, I brought the report folders inside to a semi-darkened room, carefully taking out the developing paper out of the folders, placing them glossy-side down in the mixture for three seconds. I immediately rinsed it with cold water, and let it dry for 15 minutes. I then recorded my observations.


Its Not About The Money


In conclusion, my hypothesis was correct, the cost of the product will not change the effectiveness of the sunblock. One of the cheapest sunblocks came in first, then the highest price sunblock came in second. In third place was also one of the cheapest, and in the fourth position it was an average price for sunblocks. Through my experment, I learned that it is important to know what sunscreen is good for you and which is bad. I learned that sunblock can not work so well on your skin if you don't know what you are getting to protect your body.


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Science Fair Project by Samantha DeSouza