Cosmetic Science: Testing Lip Balm Recipes
AbstractDid you know that cosmetics companies employ teams of specialized scientists to develop and test each new line of makeup, perfume, lotion, or soap? This science project lets you be the cosmetics scientist. You will create your own lip balm right in your kitchen using a short list of ingredients, then test it, and follow up with some creative cosmetics science of your own!
Thanks to volunteers at the Science Education Council at PPG industries for feedback and advice on this science project.
The idea for this project came from the DragonflyTV podcast: Twin Cities Public Television, 2007. "Makeup by Jazi and Danielle," PBS Kids Go! DragonflyTV, https://www.youtube.com/watch?v=5w_DHb6sZ2o.
- Q-tips is a trademark of Unilever United States, Inc.
Create your own homemade lip balms, test your products quantitatively, and (optionally) evaluate costumer preferences.
Believe it or not, the glamorous world of cosmetics and beauty products is actually based on serious science. Cosmetics companies employ teams of specialized scientists to develop and test each line of makeup, perfume, lotion, and soap. Their research leads to top-secret formulas that are carefully analyzed for safety, stability, performance, and customer appeal.
Cosmetics chemists choose from thousands of ingredients when they create new products, but they are always careful to select ones with chemical properties that enhance the look, feel, and use of the product they are making. For instance, no one wants lip balm to be too hard, which is why most homemade lip balm recipes call for some type of oil or butter. Oils are generally thick, viscous liquids at room temperature and are usually emollients, meaning that they soften and smoothen the skin. Butters are another kind of emollient; they are soft, but not liquid, at room temperature. On the other hand, a super soft, runny lip balm would be too messy, so waxes, like beeswax, which are solids at room temperature, are added to thicken the recipe. The "perfect" product means getting just the right ratio of emollients to waxes.
Oils, butters, and waxes are excellent ingredients for lip balms because they are occlusive agents, which means they create a physical barrier between the moisture in the lips and the outside environment. A "good" product creates a protective barrier with just one or two swipes across your lips. No one wants to go over their lips again and again before there is enough to adequately protect their lips!
What other properties do you like your lip balm to have? How about a fragrance? But be careful—no one wants a lip gloss that smells good, but tastes awful! This is another case where the chemist making the product needs to think about the properties (in this case, fragrance and flavor) of the ingredients they are using. Also, should the balm be stable and functional under cold and hot circumstances? What if people take it on a ski trip, or leave it in their car on a sunny day? The slipperiness and stickiness of a balm when applied with a specific pressure and speed is yet another parameter; scientists use machines to test these.
Are you curious about how you can replicate the process of creating and testing lip balm at home? Follow the Procedure in this science project and create four different lip balms, then put them to some rigorous quality tests. Maybe you would even like to call in a test panel to evaluate their preferences, and from there, who knows? You might come up with a recipe so good that you can use it for birthday and holiday gifts!
Terms and Concepts
- Occlusive agent
- Qualitative data
- Quantitative data
- Random order
- Why do people use lip balm? Can you relate these reasons to properties of ingredients typically found in lip balm?
- What are emollients, and why would you use them in a lip balm?
- How would you quantify or measure properties of lip balm?
- Do some research online. Can you find scientific tests that commercial companies perform on lip balm?
- Neudahl, G. (n.d.). Cosmetic Formulation Basics: What's in a Lip Balm and Why. Chemists Corner. Retrieved June 29, 2016.
- Dobos, K. (2016). How Do Skin Moisturizers Work. Chemistry Corner. Retrieved July 7, 2016.
- Castro, J. (n.d.). Cosmetic Chemistry. Chemistry Explained. Retrieved July 7, 2016.
- Twin Cities Public Television. (2007). Makeup by Jazi and Danielle. PBS Kids Go! DragonflyTV. Retrieved July 7, 2016.
- Roberts, D. (2012). Qualitative vs. Quantitative Data. Oswego City School District Regents Exam Prep Center. Retrieved July 7, 2016.
Materials and Equipment
A project kit containing the specialty items needed for the lip balm is available for purchase from Amazon.com. You will need the following items from the kit:
- Beeswax beads (30 g)
- Shea butter (2 oz)
- Sweet almond oil (2 oz)
- Lip balm tubes (12)
- Lip balm jars (4)
- Wooden stirrers (6)
- Labels to put on your tubes and jars
You will also need to gather these items (not included in the kit):
- Glass measuring cups or small, heat-proof containers; at least 1 ½ inches high and about 1/3 cup capacity (4)
- Soapy water and kitchen towel
- Digital scale with 0.1 g increments. A digital scale that would be suitable (the Fast Weigh MS-500-BLK Digital Pocket Scale) is available from Amazon.com
- Optional: Permanent markers, preferably 4 different colors.
Additional items needed for testing:
- Construction paper
- Medicine dropper or eye dropper
- Cutting board
- Paring knife
- Metric ruler
- Clean drinking glasses (4)
- Pennies (12)
- Bottle caps or small cups (4)
- Coins for a total of about 60 g; such as 11 United States quarters or other small weights
- Lab notebook
If you want to test your products on a test panel:
- Cotton swabs (Q-tips®) or flat-edge toothpicks
- Volunteers (10 or more); Note: To find out how many volunteer subjects you need, check out the Science Buddies resource
Sample Size: How Many Survey Participants Do I Need?.
- Important Notes:
- Ask each volunteer if they have any allergies or sensitivities to makeup or lip sticks. If they do, do not use them as volunteers for your experiment.
- For ISEF-affiliated science fairs, studies involving human subjects require prior approval. For more information, see Projects Involving Human Subjects.
- Important Notes:
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Making the Lip Balms
|Ingredients||Recipe A||Recipe B||Recipe C||Recipe D|
|Beeswax||6 g||6 g||6 g||2 g|
|Almond oil||9 g||18 g||0||9 g|
|Shea butter||9 g||0||18 g||9 g|
|TOTAL||24 g||24 g||24 g||20 g|
Click through the slideshow for step-by-step instructions for making the lip balm.
Testing the Water Seal
Lip balm is used to prevent the sensitive skin on our lips from drying out. This test will verify if a layer of lip balm can create a water seal. A good seal acts like a barrier and prevents moisture in the skin from evaporating.
Before you start, copy Table 2 in your lab notebook. It will help you record the data.
|Can The Lip Balm Create a Water Seal?|
|Recipe A||Recipe B||Recipe C||Recipe D|
|% of Times a Water|
Seal is Created
Testing Performance at High Temperatures
Occasionally, people leave their lip balm in the car on a sunny day, which is an environment that can get very hot. This test will examine which lip balm holds best under hot conditions.
Before you start, copy Table 3 in your lab notebook. It will help you record the data.
|Melting time in minutes when placed in an environment at 170° F|
|Recipe A||Recipe B||Recipe C||Recipe D|
Testing Stickiness at Different Temperatures
When you apply the lip balm, you want the balm to stick to the skin, regardless of the weather or ambient temperature. This test will quantify how well the lip balm sticks at room temperature, refrigerator temperature, and freezer temperature.
Before your start, copy Table 4 three times in your lab notebook: one for room temperature, one for refrigerator temperature, and one for freezer temperature. These tables will help you record the data.
|Stickiness of lip balms at ...temperature|
|Recipe A||Recipe B||Recipe C||Recipe D|
Testing Yield at Room Temperature
Some lip balm sticks create complete coverage in one rub, while others need several rubs. Some sticks seem to last forever, while others are used up quickly. These are important characteristics of lip balm, and hard to quantify with home equipment. Why is it so hard to measure them scientifically? They depend on how you apply your lip balm: whether you press firmly or softly on your stick, or whether you rub fast or slowly over your lips. This test will compare the yield when one specific pressure is applied. Do your best to keep rubbing speed constant as well.
Note that the yield could depend on the roughness of the skin or paper used. Stick to one type of paper (such as one brand and weight of construction paper) for this test. The Variations explain how you can study the yield for various roughness of skin.
Before you start, copy Table 5 in your lab notebook. It will help you record the data.
|Yield Under Constant Pressure and Speed of Application|
|Recipe A||Recipe B||Recipe C||Recipe D|
|Mass of Stick|
and Added Coins
|Number of Rubs to Create a Seal|
|Number of Seals in 10 mm stick|
Testing Customer Preference
Previous tests mainly provided quantitative data. The results were captured in numbers that can be analyzed statistically. This test will help you capture valuable qualitative data, like preferences or how volunteers rate the texture, smell, taste and appearance. The video in the Introduction shows an example. Jazi and Danielle used a test panel to study the look, feel (texture), taste, and overall performance of their products. You can also perform this type of test for three characteristics of your choice.
Before you start, make a table like Table 6 in your lab notebook. Feel free to switch the characteristics "Look," "Feel," and "Overall Performance" with the three characteristics you would like to test.
|Test Panel Results|
Analyzing Your Results
You collected a lot of data, now it is time to bring it all together. For help with data analysis and setting up graphs, check out the resource Data Analysis & Graphs.
For your quantitative data tests (these are the high-temperature performance, the stickiness tests, and the yield tests):
- Calculate the averages of all three trials and write them down in your data tables.
- Create bar graphs to represent your results. Put the lip balm recipes (A,B,C, and D) on the horizontal axis and the averages of the studied variable on the vertical axis.
- Draw conclusions. What did you learn from this test? What do your measurements tell about the lip balms? How did changing an ingredient in the recipe influence the variable studied?
For your qualitative data tests (these are the water seal test and the customer preferences test):
- Count how many times a particular answer ("yes" for the water seal, or A,B,C, or D for the customer preferences) was given.
- To translate these total counts in percentages, divide this number obtained in step 1 by the number of trials for the water seal test or the number of volunteers tested for the customer preferences test. Multiply the obtained number by 100.
- Write the percentage for the water seal test in the last row of that data table (see Table 2). Create a new table to list the percentages that a particular answer was given for the customer preferences test.
- Represent the percentages in a bar graph, where you have the lip balm recipes (A,B,C, and D) on the horizontal axis and the percentage on the vertical axis. You will have one graph for the water seal test and three graphs (one for each characteristic tested) for the customer preference test. More advanced students can visualize the customer preference test data in 1 graph where different colors represent the different characteristic.
- Draw conclusions. What did you learn from the test? What does that mean for the lip balms? How did changing an ingredient in the recipe influence the variable studied?
- Can you draw conclusions from your study? Are there areas that need more study? Did your project bring about new questions?
Ask an Expert
- This project lists four recipes. Search online for other recipes to test and try, or make your own recipe. You can also switch ingredients to different products from the same category, like switching almond oil to coconut oil. Use the things you learned from your background research to make your new recipes complete.
- Perform the quantitative tests on commercial lip balms and see how these compare to your lip balms. Also compare the ingredient lists. Which ingredients are commonly added to commercial lip balms that are not in your lip balms? What is the function of these ingredients? How could you replace it in a homemade lip balm if you wish to do so?
- Analyze the "shelf life," or stability, of your lip balms. After testing is completed, leave the lip balm samples out at room temperature, with their lids securely fastened. Carefully observe your lip balms each week and watch for signs of spoiling, such as changes in color, texture, or smell. Record your observations and note how long each sample remains stable. Research the preservatives and stabilizers used in commercial lip balms or cosmetics. Are there similar ingredients in your balms?
- Research the typical shelf life of cosmetics. Ask your friends and family how long they usually keep their makeup, soaps, or lotions. How many of them know or follow the manufacturer's guidelines?
- This project studied the yield of the lip balm sticks when applied with one particular pressure and at one particular speed. Could you extend this study and see how yield changes with pressure and/or speed? You can also keep the pressure and speed constant, but study how the yield changes with roughness of surface by applying the test on paper with increasing roughness, or you can study how the yield changes with changing temperature.
- Do research on rheology (the science of flow and deformation) and biotribology (the science of friction and lubrication related to humans or animals) and how these are used in skincare products. Can you reproduce scientific tests used in these disciplines on your products at home?
- If you would like to test the moisturizing effect of the balms, check out the following project to get ideas of how this can be done: The Skinny on Moisturizers: Which Works Best to Keep Skin Moist?.
- Create a different product like hand lotion or soap. Do some research to find how commercial products of this category are tested. Perform an at-home version of the tests on your products and/or do a customer preferences test.
If you like this project, you might enjoy exploring these related careers:
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