Curtis Brown, a science teacher in Aberdeen, South Dakota, says there are several different types of cosmetic science projects that you can do for a science fair or just for fun at home. He says cosmetics are an important part of society, so it is a relevant topic to discuss in a science project. He reminds you that you should always be asking a question when doing a science fair project.

Do an experiment about different types of cosmetics and how long they last. You can do this by putting cosmetics on and seeing if they wear off. Choose a variety of different types of cosmetics, and test them on a wax dummy or on your own face. Brown says if you are going to do this, you should enlist the help of several people to try each cosmetic, so you can have a result that isn't tainted. If you are doing the experiment on your own, you might rub off the cosmetic or there might be another reason that one lasts longer or for less time for you in particular. Get several people to participate, and then have them try out various cosmetics and make an experiment based around which of them last the longest amount of time.

Other cosmetic science projects might revolve around how to best remove cosmetics. This is a major thing people are concerned with when they think about cosmetics. Choose a thing, like your face, your clothing or a piece of paper, that you want to get cosmetics off of, and then do an experiment that finds out what removes the cosmetics the best. You can see which type of soap gets cosmetics off your face the best, or you can rub cosmetics onto a piece of fabric and try to use different things, like laundry soap, dish soap or bleach, to see which removes the cosmetics the best.

Remember to follow the scientific method when creating a science experiment on cosmetic. Brown reminds you that you first must must decide on a question that you would like to discuss. After you choose a question, you need to come up with a hypothesis or a guess a to what the answer might be. If you were doing an experiment on lasting cosmetics, your question might be "which cosmetic lasts the longest" and your hypothesis might be "NYC Cosmetics." The next step is to do research on the topic--research on cosmetics, or on what you are doing with them, such as removal. Then, you need to do an experiment, in which you actually test your hypothesis. Have several cosmetic types and see how long they last, or expose them to water or other liquids and see which ones stay put the longest. After you do your experiment and collect data, look at your data to determine whether your hypothesis was right or wrong. Then, display your answer as your conclusion.

Brown reminds you that experiments about which type of cosmetics work best or which look best, are going to be subjective and aren't going to be good for a science fair. See if you can find a question about cosmetics that you can test, and then build an experiment from there.