Cosmetics are a very broad spectrum with a plethora of chemistry incorporated into it. More specifically, lip cosmetics are practically built on the basis of chemistry. There is a range of lip products, from lip balms, to lip glosses, to lipsticks. One side of the spectrum is more aimed towards dermatology and actual skin care, while the other side is more focused on cosmetic appearance with a dramatic and eye-catching look. However, all of these share very similar chemical components in their make-ups. These products are used all over the world and chemically constructed specifically and safely for their purposes. Waxes, oils, emulsification and other additives make up a greater whole in lip cosmetics.
Lip balms are the base of lip products. They provide moisture and a smooth base to apply other aesthetic cosmetics. Dry air, mostly occurring during the winter in northern regions, can pull moisture from the lips and cause the thin skin to easily become dry and cracked. Lip balm is most recommended to be applied before lips can become dry, or especially before one enters a dry air climate. “Occlusive materials help prevent moisture loss by forming a barrier over the upper layer of the skin” (Brunning, 2016). Occlusive materials include an umbrella of compounds such as petroleum jelly, dimethicone and other waxes. Petroleum jelly is often seen as medicinal soft paraffin wax, including multiple hydrocarbons such as “paraffins (15-60%) naphthenes (30-60%) aromatics (3-30%) asphaltics (remainder)” (Helmenstine, 2018). “Petroleum jelly provides a good base ... because it is chemically inert. Since it is made of hydrocarbons and there are no dipoles, the only force occurring in this substance is London Dispersion Force (LDF), which is stronger because of the long chain of hydrocarbons, creating a melting point up to 75°C. London dispersion forces occur when the electrons of a molecule are arranged so that the electron density on one side of a molecule or atom is much greater than that of the other side of the atom” (Anne, 2018). This makes it difficult for water to leave the barrier on the lips, simply because the London Dispersion Forces will prevent this because the molecules in the petroleum jelly only contain both hydrogen and carbon atoms. Dimethicone (C11H28O4Si2), like petroleum jelly, provides a barrier to seal moisture into skin.
Less commonly known is the idea that lips are one of the easiest parts of the human body to be sunburnt. This is why many cosmetic “manufacturers will often include molecules that absorb UV light” (Brunning, 2016). Oxybenzone (C14H12O3), an aromatic ketone, is just one component that is used to protect against UV light that could cause sun damage. Additionally, manufacturers will add “linalool, citral, and geraniol” (Brunning, 2016) to improve scent, which greatly aids in the process of advertising products. Linalool and geraniol are both floral fragrances while citral, as the name would suggest, is a citrus scented.
Lip glosses begin to enter the realm of decorative and dramatic cosmetics. Lip glosses are used less often than lip balms and enhance the gloss of the lips. Normally, they are not advertised as medicinal and otherwise, a cosmetic care product. However, lip glosses do provide moisturizing and protecting properties, similar to lip balm. “[London Dispersion Forces] create hydrophobic interactions” (Anne, 2018), meaning that these weak intermolecular forces do not let petroleum jelly, another reoccurring ingredient in lip products, form intermolecular attractions with water. This creates a barrier between the lips and the air, making it more difficult for H2O to leave the skin. Oils are another ingredient in lip gloss, which help keep the lip gloss on the lips, and also help keep the lips moisturized. Oil molecules are nonpolar, making them also hydrophobic.
Waxes will help to extend the wear of the lip gloss. Most commonly used is beeswax (C15H31COOC30H61). “The molecules of waxes typically found in lip gloss are composed of ester and alcohol groups, in addition to many carbon-hydrogen molecular bonds. The presence of the ester and alcohol groups allows part of the molecule to be polar. Therefore, the alcohol ends participate in dipole-dipole intermolecular forces” (Anne, 2018). The section of the molecule containing hydrocarbons, however, is nonpolar. This will attract other nonpolar molecules. This establishes the texture of lip glosses. Lip gloss contains both hydrophobic substances, such as oil, and hydrophilic materials like aloe vera. These still become a homogeneous mix that we call lip gloss, because lip gloss is an emulsion. “In an emulsion, the hydrophobic materials attach to the emulsifier and divide into many microscopic micelles” (Anne, 2018). Because of this, the nonpolar molecules of the lip gloss are not as often exposed to H2O, lessening the hydrophobia. Without the emulsion, oil would be suspended in the water. Or, if less used, the oil would entirely separate from the water. This would make the lip gloss nearly unusable for its actual purpose. The added emulsifiers homogeneously suspend the oil throughout the water, making it usable like the lip gloss that is seen today. “Van der Waal’s forces relate to the non-polar attractions between molecules due to transient polarization of electron clouds. Though LDF is one of the weakest forces, it is most prominent in lip gloss by preventing water molecules from passing through the solution and being evaporated” (Anne, 2018). Conclusively, lip gloss aids in moisturization and lessens the drying of one’s lips from the further evaporation of moisture that could take place.
Lipstick is likely the most well known lip cosmetic on the market. This, while can have some enhancing properties, is mostly advertised for aesthetics and eye-catching makeup. Red lipstick is a common example of this. Red lipstick is a red colored, solid tube made of “65% castor oil, 15% beeswax, 10% other waxes, 5% lanolin, and 5% dyes, pigments and perfumes” (Compound Interest, 2017). Oils give skin softening properties along with making it easier to apply. The oils also attribute to the possible glossy appearance that a lipstick could hold, and it also acts as a solvent for dyes later added to the lipstick composition. Most commonly used is castor oil (C57H104O9), which is a vegetable oil. It is typically stable in high heat. Waxes also make up a large portion of the lipstick, as they are the base of it. They are crucial for both the structure and shape of the lipstick. “Beeswax is composed of around 300 different chemical compounds; the principal compounds are esters, which make up around 70% of the composition. The remaining 30% of compounds includes organic acids and hydrocarbons” (Compound Interest, 2017). Another wax that is commonly used is Carnauba wax “which at approximately 87˚C has the highest known melting point of any wax” (Compound Interest, 2017). This wax is used because of its extremely high melting point. Lipstick is meant to hold its form and shape so it can be applied. If it is kept in a warmer area, because of this wax, it is less likely to deform and melt. Both waxes help to emulsify and bind other ingredients in the mixture of the lipstick composition.
Pigments and dyes, though are the focal point are lipstick, are actually a very small percentage of the lipstick composition. Carmine red, or carminic acid, is a very commonly used red pigment which is derived from shelled bugs. “It is prepared by boiling the insect bodies in ammonia or sodium carbonate solution, filtering, and then adding hydrated potassium aluminium sulfate (more commonly known as alum)” (Compound Interest, 2017). Eosin is also a dye that is used. When applied, it subtly changes color. The actual lipstick tube is a brighter red with a blue tinge or undertone. When applied, it actually reacts with amine groups found in proteins in the skin, deepening and intensifying the red. This also makes the lipstick more long lasting. Iron oxide, or more commonly coined as rust, is used as an inorganic, man-made coloring agent in some lipsticks, as well. They are often made by the precipitation of iron salts with oxidation. Iron oxides molecular formula is Fe3O4. Red is also not the only lipstick color on the market. There are a huge spectrum of shades available to purchase. Titanium dioxide, for example, is solemnly a white compound, but when added to red pigments, it becomes a lighter color, changing to pink. Depending on how much or how little is added, it can change the color of pink that the lipstick holds. Lipstick often does not have a pleasant smell without some kind of fragrance, so esters are added to help mask the scent and flavor. Capsaicin is a compound found in chilis that is responsible for the spicy aspect of them, and is actually added to lipsticks and other lip products. This compound irritates the skin just enough to plump lips, which is often sought among recent years in the cosmetic industry.
The industry in itself is not perfect. There could most definitely be dangers among these products, as they are applied directly to one’s face, which is one of the most vulnerable skin areas on the body. “A 2013 study by the University of California Berkley examined the metal content of 32 different lipsticks. Researchers found traces of aluminium, manganese (which can cause neurological problems) and titanium in all the products they tested, while three-quarters of the products contained lead (which affects the nervous system, and can cause learning disabilities in children). Many of the lipsticks and lip glosses also contained nickel and cobalt, as well as cadmium and chromium—both known carcinogens” (Jones, O., & Selinger, B., 2017). While this may be the case, manufacturers do not actually include these ingredients purposefully into their products. They often naturally occur in the other ingredients added. While these were, no doubt, found in common lipsticks, it does not necessarily mean that they will directly cause everything as listed. The actual amounts of such traces were so small that they could, realistically, cause little to no harm to ones body. However, in response to this, many companies have removed as many ingredients as possible that were listed.
Cosmetics and chemistry go hand in hand. The chemistry of lip cosmetics, while not perfected, is an advanced industry that continues to grow every year. While the actual composition of lip products has not changed much in many decades, there is no predicting of what is to happen in the future. Could there be chemical advancements in the very close future that completely flips the lip cosmetic industry upside down? Absolutely. Improvements are made everyday and the industry can only grow and get better from here.
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