The Chemistry of Lipstick

Format
Subjects
John Woodliffe
Readability
8.48

How does this align with my curriculum?

Learn about the organic compounds that make up lipstick as well as about some of the chemistry that goes into this popular cosmetic.

Did you know that cosmetics have probably been used for over 6 000 years? In ancient Egypt and China, both women and men used chemicals to darken their eyelids and paint their nails. Over time, people have used clay to create cosmetic pastes, and crushed rocks and minerals to create body paint. 

Woman Applying Color to Her Lips (woodblock on paper, 1920).
Woman Applying Color to Her Lips (woodblock on paper, 1920). (Source: Goyō Hashiguchi. Public domain image via Wikimedia Commons).

 But what about the cosmetics you might see in your local drugstore? What is the chemistry behind modern makeup, and is it really safe to use?

What's in makeup?

Cosmetics are made up of many different components. One of the main ones is water. Many cosmetics are based on oil-in-water emulsions, small droplets of oil dispersed in water. Many others are based on water-in-oil emulsions, small droplets of water dispersed in oil. The cosmetics also contain an emulsifier, a substance that allows liquids to mix when they otherwise wouldn’t. In cosmetics, emulsifiers hold the water and oil together in a nice mixture, stopping them from separating and forming layers.

Many cosmetics also contain alcohol, which works as a solvent. A solvent is something that carries or dissolves other ingredients. A nice example of solvent use in cosmetics is in nail varnish or polish. The solvent carries a polymer with colour pigments. After it evaporates, you’re left with a colourful film on your nails.

The common substances in makeup include preservatives, thickeners and emollients
The common substances in makeup include preservatives, thickeners and emollients (©2019 Let’s Talk Science).

 

Infographic - Text Version

Preservatives prevent the growth of microorganisms, thickeners give products a nice texture and feel and emollients soften the skin by preventing water loss.

 

Makeup manufacturers then add colour, shine and a fragrance to give you an attractive and pleasant-smelling product!

What are the ingredients in lipstick? 

Let’s now look specifically at lipstick, where the main components are waxes and oils. These are compounds containing mainly hydrogen and carbon. The wax is what gives the lipstick its structure and glossiness. Chemists add a wide range of naturally-occurring waxes to lipstick. For example, they might add beeswax, which mostly contains esters, organic acids and hydrocarbons.

Did you know? 

During the Second World War, British Prime Minister Winston Churchill rationed all cosmetics except lipstick. He said lipstick boosted morale!

Chemists add various other ingredients to lipstick. For example, they add oils, such as olive oil, which soften the lip skin and add glossiness. Pigments and dyes provide the colours, and fragrances then cover up the nasty smell of the other chemicals. 

Did you know? 

A common pigment in red lipstick is carmine red, which is derived from boiling an insect! 

 

Chemical structure of carminic acid and scale insect
Left: Chemical structure of carminic acid (Source: Dschanz via Wikimedia Commons). Right: The scale insect (Dactylopius coccus) produces a red dye when crushed (Dick Culbert [CC BY 2.0] via Wikimedia Commons).

Some lipsticks even contain the compound capsaicin,  which is the cause of spiciness in chili peppers. Capsaicin irritates the skin and causes it to plump up! 

Hot peppers and chemical formula of capsaicin
Left: Hot peppers (Source: Elle Hughes via Unsplash). Right: Chemical formula of capsaicin (via chemspider.com).

The chemist’s job doesn’t end with the basic ingredients. Chemists have to overcome certain issues so that their products will be effective - and popular.

One such issue is melting. Lipstick wouldn’t be much good if the solid waxes melted on  your lips and ran down your chin! To solve this problem, chemists mix in some carnauba wax, which has a high melting point of around 87°C.

Is lipstick safe?

Now that you know about all the chemicals in lipstick, you may ask if it’s really safe to put lipstick on your lips. In general, yes. The Canadian government maintains a Cosmetic Ingredients Hotlist of ingredients that are not safe to use in cosmetics.  Products that contain these ingredients cannot be sold in Canada.

Also, cosmetic products are extensively tested. Sometimes, cosmetics are tested on animals before they are sold to humans. But many countries have stopped using animals for cosmetic testing. In fact, many countries have banned all products tested using animals. As of 2019, the Canadian government is considering banning these products, too. The animal advocacy group PETA lists computer modelling, research with cells and tissues, and human volunteers as ways to test cosmetics without using animals.

 

Starting Points

Connecting and Relating

  • Do you wear lipstick? Do you like the look of lipstick? Why or why not? 
  • Would you use a lipstick if you knew that it had been tested on rabbits? Why or why not?
  • Do you read the ingredients list on the makeup you use? Have you considered the types of ingredients that go into making lipstick? Do you ever worry about putting unfamiliar ingredients on your lips? Why or why not?

Connecting and Relating

  • Do you wear lipstick? Do you like the look of lipstick? Why or why not? 
  • Would you use a lipstick if you knew that it had been tested on rabbits? Why or why not?
  • Do you read the ingredients list on the makeup you use? Have you considered the types of ingredients that go into making lipstick? Do you ever worry about putting unfamiliar ingredients on your lips? Why or why not?

Relating Science and Technology to Society and the Environment

  • What health and safety testing goes into cosmetic products such as lipstick?
  • What other industries and resources does the cosmetics industry rely on?  

Relating Science and Technology to Society and the Environment

  • What health and safety testing goes into cosmetic products such as lipstick?
  • What other industries and resources does the cosmetics industry rely on?  

Exploring Concepts

  • What are the chemical formulae and structure of beeswax and carnauba wax? What are the melting point temperatures of each? What can account for the difference in melting temperature?
  • Lipstick and other cosmetics come in a wide variety of colours. Conduct research to learn more about the sources of some of these colours? 
  • Research the alternate methods to animal testing that are available to cosmetics companies.

Exploring Concepts

  • What are the chemical formulae and structure of beeswax and carnauba wax? What are the melting point temperatures of each? What can account for the difference in melting temperature?
  • Lipstick and other cosmetics come in a wide variety of colours. Conduct research to learn more about the sources of some of these colours? 
  • Research the alternate methods to animal testing that are available to cosmetics companies.

Nature of Science/Nature of Technology

  • There are differing opinions about using animals for testing cosmetics. What is your opinion? Explain. 
  • Using animals to test the safety of cosmetics is an ethical issue. Many people dislike and disagree with this practice of safety testing. How can the public influence and effect change when is comes to ethical issues such as this? What processes are more effective at creating permanent changes in practice?

Nature of Science/Nature of Technology

  • There are differing opinions about using animals for testing cosmetics. What is your opinion? Explain. 
  • Using animals to test the safety of cosmetics is an ethical issue. Many people dislike and disagree with this practice of safety testing. How can the public influence and effect change when is comes to ethical issues such as this? What processes are more effective at creating permanent changes in practice?

Media Literacy

  • Gather examples of recent lipstick advertising. How is science used to promote these products? Do you think it matters to consumers if the science in this advertising is accurate and relevant? Why or why not?  

Media Literacy

  • Gather examples of recent lipstick advertising. How is science used to promote these products? Do you think it matters to consumers if the science in this advertising is accurate and relevant? Why or why not?  

Teaching Suggestions

  • This article can be used to look at the application of chemistry and the sources and properties of materials in a common item – lipstick. The concepts covered in this article include chemical formulae and physical properties of matter, including melting point. The article also addresses the concept of health and safety of chemical ingredients in personal products.  
  • Before reading the article, the teacher could conduct a short class discussion to get students thinking about the cosmetics and personal products they use everyday and the chemical ingredients they contain. Questions to lead the discussion might be:
    • What cosmetics and grooming products do you regularly use on or in your body?
    • Do you know what chemicals are in these products? 
    • Do you ever read the ingredients list? What do you know about each of these ingredients? Do you know why they are included in the formulation of the product?
    • Do you have safety concerns about the chemicals that may be in these products? Why or why not? 
  • After reading the article students could examine ingredients labels from some common grooming and make-up products and attempt to classify the ingredients by their purpose in the product and/or their chemical properties. This task could require additional research to find out more about the chemistry and properties of each ingredient. 

Teaching Suggestions

  • This article can be used to look at the application of chemistry and the sources and properties of materials in a common item – lipstick. The concepts covered in this article include chemical formulae and physical properties of matter, including melting point. The article also addresses the concept of health and safety of chemical ingredients in personal products.  
  • Before reading the article, the teacher could conduct a short class discussion to get students thinking about the cosmetics and personal products they use everyday and the chemical ingredients they contain. Questions to lead the discussion might be:
    • What cosmetics and grooming products do you regularly use on or in your body?
    • Do you know what chemicals are in these products? 
    • Do you ever read the ingredients list? What do you know about each of these ingredients? Do you know why they are included in the formulation of the product?
    • Do you have safety concerns about the chemicals that may be in these products? Why or why not? 
  • After reading the article students could examine ingredients labels from some common grooming and make-up products and attempt to classify the ingredients by their purpose in the product and/or their chemical properties. This task could require additional research to find out more about the chemistry and properties of each ingredient. 

Learn more

The chemistry of cosmetics (2017)

Article by the Australian Academy of Science provides more extensive information with pictures and an interactive tool that shows the chemical contents of typical cosmetics.

What’s that stuff? Lipstick (1999)

Article from Chemical & Engineering News giving an entertaining personal account by a scientist of her interest in lipstick, its history, and what goes into it.

The Compounds in Red Lipstick (2014)

More details of what goes into red lipstick including an interesting infographic from Compound Interest and some discussion of health concerns.

References

Johnson, R. (1999). What's that stuff? LipstickChemistry & Engineering News77(28), 31.

Rodger, C., & Broughton, D. (1998). The in-situ analysis of lipsticks by surface enhanced resonance Raman scattering. Analyst123(9), 1823–1826. DOI: 10:1039/A805275A