Hello, Sunscreen! Do I know you?:

By Huijing Y., with contributions from Hannah Gibson and Chahana P.

When summer comes, people like to visit beaches and enjoy outdoor activities. Sunscreen becomes indispensable for people to protect their skin from sun damage and skin cancer. As consumers, we determine what sunscreens to use and buy. Do the public/consumers know enough information about sunscreens? Do they actually protect our skin? Let’s find out.

To investigate how much people know about sunscreen, we distributed a survey to approximately 60 people. 33 responded. Most were high school students. Some were teachers or adults from non-profit organizations. Their ages range from 15 to 40.

Here is a summary of our survey results:




According to our survey, 76% of the respondents use sunscreen. It is a good sign that the majority of people are aware of the harm of being exposed to sunlight. So they take their first action and start to use sunscreen. However, most of the respondents do not use the sunscreen when it is cloudy or cold outside; indicating that people do not believe that they could still be harmed by UV when it is cloudy or cold.

Let’s talk about how much people know about sunscreen. Half of the respondents state that they know what the SPF is. But none of the respondents could write it out in this 2-minute survey. In fact, SPF stands for Sun Protection Factor. It refers to the theoretical amount of time you can stay in the sun without getting sunburned. For instance, if your skin starts to redden in 10 minutes without using sunscreen, applying a sunscreen with SPF 15 increases that time by a factor of 15, indicating you could stay in the sun for 150 minutes. Also, a higher SPF blocks out more UVB: a product with SPF 15 could filter out around 93%, a product with SPF 30 filters out around 97%.

It seems like higher SPF means better protection for your skin. 59% of respondents believe higher SPF would provide more for their skin. In fact, there is not enough evidence to prove that higher SPF provides better protection since the amount of skin protection depends on how sunscreen is used. For example, the longer sunscreen stays on the skin, the more it will be wiped off by clothes and sweat and the less skin protection it provides. Sunscreen should protect skin from UVA and UVB. But SPF is only applied to the UVB. Consumers should be aware of the ingredients—zinc oxide and titanium dioxide, which can protect skin from UVA. Above all, consumers only know basic information about sunscreen.

We found out what we can do to educate people about sunscreen. We found out most respondents buy sunscreen in a convenience store where the salespeople don’t know much about sunscreen. Consumers hardly get sufficient information when they ask salespeople questions about sunscreen. Also, salespeople in cosmetic stores are considered to be professionals. Consumers are likely to trust what they say about the sunscreen. However not all salespeople in cosmetic stores understand how to use sunscreen properly and how to choose a good sunscreen. Based on this, we propose these tips for consumers looking to buy sunscreen.

  • Find credible articles online about SPF and sunscreen protection.
  • Read the ingredients on the product before buying it.
  • Ask your family doctor how to use sunscreen properly and effectively.

Now we know sunscreen. Next time you see some, say out loud, ”Hey sunscreen, how’s it going?”

Sunscreen Talk: What is really in our sunscreen?

By Rakeb Girma, Teya Stevens, Venus Montgomery, and Hannah Gibson

On November 7th we called Neutrogena and asked them three questions regarding our sunscreen experiment and sunscreen regulations. After a long wait and one crazy story to tell(a whole other story), we talked with a representative named Geoff. The first question we asked was “What is the highest effective SPF value?” In reply the Neutrogena representative said the highest effective SPF value is 100 because that is the highest allowed by the FDA. In reality, the highest approved SPF value is 50. “The FDA now says that there is no legitimate evidence to suggest that anything above SPF 50 will provide increased protection (Wazer, 2011, Why You Don’t Have To Wear SPF 100 Anymore).”  Another question we asked the representative was, “What is the difference between sunscreen and sunblock?” His response was, “Sunscreen is a chemical substance used to protect skin from UV from the sun.”

Sunscreen contains many chemicals and we wanted to learn more about the sunscreen manufacturing process.

After chemists and dermatologists develop the formula for sunscreen, they make small ten gallon batches in stainless steel vats to be tested by the company and the FDA. If the sunscreen is approved, more batches of sunscreen are made in bigger vats that hold up to 1,000 gallons of sunscreen. Purified water is a key ingredient in sunscreen. Water is purified by reverse osmosis, where it is pushed through a filter that removes dissolved salts and metals. The other ingredients are then added. To make the containers, molten plastic is blown into a mold shaped like the bottle. The plastic cools to form a hollow container in the exact shape of the mold. Sometimes a bottle manufacturer stamps a logo onto the plastic while it is hot.  The bottles are filled by tubes connected to the 1,000 gallon vats and capped by a capping machine.

We also wanted to learn about harmful chemicals in sunscreen.

In sunscreen there are many different types of harmful ingredients. A harmful ingredient in sunscreen is retinyl palmitate. Retinyl palmitate may cause cancer or tumor growth. If women who are pregnant use products that have retinyl palmitate in it, their unborn child may have birth defects. A second harmful ingredient in sunscreen is oxybenzone.  Oxybenzone can cause hormone disruption. Oxybenzone can also cause cell damage. Another thing oxybenzone can cause is allergies. Finally, mothers who are expecting baby girls should not use products that have oxybenzone in it. When born, the baby girls would be underweight as a result.

Beach day gone wrong! Our sunscreen experiment.

By  Courtney E., Nathy M., and Chahana P.

Is your skin really safe from the sun when you use sunscreen? Science Club for Girls Media Team did a full experiment to test the difference between using sunscreen and no sunscreen. In our experiment, we first began with a petri dish with a layer of Yeast-Extract Dextrose (YED), a gel-like substance that allows the yeast to grow. We then applied a UV-sensitive yeast strain on top of the gel evenly (the UV-sensitive yeast uses the YED to grow when exposed to sunlight). We decided to use UV-sensitive yeast because this particular strain has a similar structure to DNA; it repairs itself when exposed to UV radiation with sunscreen.

We marked the petri dish into four sections, each labeled with: Sun (no sunscreen), No sunscreen and sunlight, sunscreen type A, and sunscreen type B. We had one side labeled “no sunscreen and sunlight” because we wanted to see the effect of not wearing sunscreen versus having it on; we had this section covered with duct tape. The duct tape represented clothing or zero sunlight. The left sections were exposed to sunlight for about 20-30 minutes. After leaving the yeast alone for a week, the majority of the data confirms that the areas with sunscreen were more protected than the area with no sunscreen. The section that was covered with duct tape was able to grow yeast even though it was covered.

In conclusion, our skin needs sunscreen because it protects us. Not using sunscreen can make our cells unrepairable due to the UV-radiation damage. Next time you head for the beach, apply sunblock!