Science Buddies: "Ask an Expert"

Hi -
I am in 7th grade and wanted to do the experiment with the UV monitor where you test the effectiveness of different sunscreens. But it is cold here in Chicago and the UV index has not been over 1. So I don't think it would be possible to do this outdoors and see a change. Would it be OK to do the experiment indoors, with a special UV light or in one of those tanning places in the mall?

Hi,

Yes, it should be possible to use a UV light or a tanning bed to obtain results for this project. I would suggest a UV light, because then you will know the exact strength of the light. Some tanning beds may also attempt to decrease harmful UV radiation.

Good luck!

Thank you so much! Can my mom & I get a UV light bulb at a store like Home Depot? Is there a special kind we should look for? Again - thank you so much for helping me save my project!! You are the best!!

Hello cheeselover101,
Thank you for your question! This sounds like a fun project and I will be interested to learn what you find out.

Is this the one you are doing? https://www.sciencebuddies.org/science- ... #materials

For this project you will need a UV monitor, it costs about $25 on Amazon (look for the link on the project page). Keep in mind that this tool is not very effective for measuring UV for lightbulbs. As far as the light is concerned, sunny weather will be an issue for you, and the UV index is low. You can definitely do this project indoors using a UV light. Read the project to learn more about the different wavelengths of ultraviolet light. You can buy a black light, which will provide you with UVA light.
If you go the lightbulb route, you will need additional UV blocking safety glasses, which you can find on amazon or industrial materials store.

Here are some questions for you to explore:
What did you find out about different sunscreens: which lightwaves do they block? What is the difference between long (ultraviolet A), medium (ultraviolet B), short wavelengths (ultraviolet C) and how does each affect the person exposed to them? How does low UV index affect the effectiveness of sunscreens.

Here is a good start for information on sunscreens.
http://en.wikipedia.org/wiki/Sunscreen
http://www.presun.com/UV.html
http://www.epa.gov/sunwise/uviscale.html

1. One thing you might do is to use UVA/ blacklight instead of how the experiment is normally setup. You can discuss the significance of UVA light and how it differs in coverage than UVB light.
2. Another idea is to complete the experiment where you live, even though it is cold, the UV index can still be high. Also, because of the reflectiveness of snow (and also water), this causes sunlight to bounce of the surface and onto our skin. That is why you can still get a sunburn while being in the snow (see weblinks above for more explanation).
3. Questions to consider, and putting into your final analysis/ conclusions: Does UV index affect whether or not sunscreen is effective? Why do skiiers wear sunscreen even in the cold weather? Can you get a sunburn when it is cloudy outside?

Please let me know if any of that information was confusing or you have more questions about it. I'd be glad to help and follow your progress. Cheers!

I'm doing this project in New Zealand and its going into winter here so I'm worried the UV index won't be strong enough to test the sunscreen. I've purchased the UV monitor from Amazon and am waiting for it to arrive.

What type of UV light do you recommend to do the test indoors. Is there a UV light which has UVA and UVB?

Hi Sofia,

As mentioned in the above posts, you are able to do this experiment indoors. They do sell lights on Amazon that emit both UVA and UVB light. Is this where you were planning to buy one from? But I would think that you would be able to use many different kinds of UV lights to perform the experiment.

Let us know what you plan to do and we can try to help you further.

Best,
Pharma