1. Definition Glycolic Acid:

Glycolic acid is a type of alpha hydroxy acid (AHA) derived from sugar cane. It is known for its exfoliating properties and ability to penetrate the skin deeply, making it a popular ingredient in skincare products.

2. Use:

Glycolic acid is commonly used in cosmetics for its exfoliating properties. It helps to remove dead skin cells, unclog pores, and improve the overall texture and tone of the skin. It is often found in products such as cleansers, toners, serums, and peels.

3. Usage Glycolic Acid:

When using products containing glycolic acid, it is important to start with a lower concentration to avoid irritation. It is recommended to gradually increase the frequency of use as your skin becomes accustomed to the ingredient. It is also important to use sunscreen daily when using glycolic acid, as it can increase skin sensitivity to the sun.

Precautions: While glycolic acid can be beneficial for many skin types, it may not be suitable for those with sensitive skin or certain skin conditions. It is important to do a patch test before using products containing glycolic acid to check for any adverse reactions. It is also recommended to consult with a dermatologist before incorporating glycolic acid into your skincare routine.

4. References:

- Ditre, C. M., Griffin, T. D., Murphy, G. F., Sueki, H., & Telegan, B. (1996). Effects of alpha-hydroxy acids on photoaged skin: a pilot clinical, histologic, and ultrastructural study. Journal of the American Academy of Dermatology, 34(2), 187-195.

- Kornhauser, A., Coelho, S. G., & Hearing, V. J. (2010). Applications of hydroxy acids: classification, mechanisms, and photoactivity. Clinical, Cosmetic and Investigational Dermatology, 3, 135-142.

- Sharad, J. (2013). Glycolic acid peel therapy – a current review. Clinical, Cosmetic and Investigational Dermatology, 6, 281-288.

1. Definition Allantoin:

Allantoin is a compound that is naturally found in plants such as comfrey and is also synthetically produced for use in cosmetics. It is known for its soothing, healing, and moisturizing properties, making it a popular ingredient in skincare products.

2. Use:

Allantoin is commonly used in cosmetics for its ability to promote skin regeneration and repair. It helps to soften and smooth the skin, making it an effective ingredient in products designed to treat dry, rough, or damaged skin. Allantoin is also known for its anti-inflammatory properties, making it a great option for soothing irritated or sensitive skin.

3. Usage Allantoin:

Allantoin is typically found in creams, lotions, serums, and other skincare products. It can be used in a variety of formulations, including moisturizers, exfoliants, and anti-aging treatments. When using products containing allantoin, it is important to follow the instructions provided by the manufacturer and to patch test the product before applying it to larger areas of the skin to ensure compatibility.

4. References:

- Draelos, Z. D. (2010). Cosmeceuticals. Elsevier Health Sciences.

- Mukherjee, P. K., & Maity, N. (2011). Acute oral toxicity study of Allantoin in Swiss albino mice. International Journal of Research in Pharmaceutical and Biomedical Sciences, 2(3), 1247-1251.

- Vaughn, A. R., Clark, A. K., Sivamani, R. K., & Shi, V. Y. (2019). Natural oils for skin-barrier repair: ancient compounds now backed by modern science. American Journal of Clinical Dermatology, 20(3), 285-295.

1. Definition Zinc Pca:

Zinc Pca (Zinc Pyrrolidone Carboxylic Acid) is a compound that combines Zinc with L-Pyrrolidone Carboxylic Acid. It is commonly used in cosmetics for its anti-inflammatory, antimicrobial, and sebum-regulating properties.

2. Use:

Zinc Pca is primarily used in skincare products such as cleansers, toners, serums, and moisturizers. It is known for its ability to help control excess oil production, reduce acne and blemishes, and soothe irritated skin. Zinc Pca is also used in hair care products to help regulate sebum production on the scalp and promote a healthy scalp environment.

3. Usage Zinc Pca:

When using products containing Zinc Pca, it is important to follow the instructions provided by the manufacturer. It is generally safe for most skin types, but individuals with sensitive skin may want to do a patch test before applying it to their face or body. It is recommended to start with a lower concentration of Zinc Pca and gradually increase the usage if needed. Overuse of products with Zinc Pca may cause dryness or irritation, so it is important to monitor how your skin reacts to the ingredient.

4. References:

- Draelos ZD. Essential fatty acids in dermatology. J Drugs Dermatol. 2010;9(6): 669-673.

- Pazyar N, Yaghoobi R, Rafiee E, Mehrabian A, Feily A. Skin wound healing and phytomedicine: a review. Skin Pharmacol Physiol. 2014;27(6):303-310.

- Brandt S. The clinical effects of zinc as a topical or oral agent on the clinical response and pathophysiologic mechanisms of inflammatory acne. J Drugs Dermatol. 2013;12(5):542-545.

1. Definition Potassium Hydroxide:

Potassium Hydroxide, also known as caustic potash, is a strong alkaline compound that is commonly used in cosmetics as a pH adjuster and emulsifying agent.

2. Use:

Potassium Hydroxide is used in cosmetics to regulate the pH levels of products, ensuring that they are gentle and non-irritating to the skin. It is also utilized as an emulsifying agent, helping to blend oil and water-based ingredients together to create stable and uniform formulations.

3. Usage Potassium Hydroxide:

When using Potassium Hydroxide in cosmetics, it is important to handle it with care due to its caustic nature. Proper safety precautions should be taken, such as wearing protective gloves and goggles, and ensuring good ventilation in the workspace. It should be added to formulations slowly and with caution to prevent splashing and skin irritation. Additionally, it is crucial to follow recommended usage levels to avoid potential skin sensitization or chemical burns.

4. References:

- "Potassium Hydroxide." Cosmetics Info, cosmeticsinfo.org/ingredient/potassium-hydroxide.

- "Potassium Hydroxide in Cosmetics." Truth In Aging, truthinaging.com/ingredients/potassium-hydroxide.

- "Safety Assessment of Potassium Hydroxide as Used in Cosmetics." Cosmetic Ingredient Review, cir-safety.org/sites/default/files/potassium.pdf.

1. Definition Sodium Benzoate:

Sodium Benzoate is a preservative commonly used in cosmetics to prevent the growth of bacteria and fungi in products. It is a sodium salt of benzoic acid and is known for its antimicrobial properties.

2. Use:

Sodium Benzoate is used in a wide range of cosmetics, including skincare products, hair care products, and makeup. It helps extend the shelf life of these products by inhibiting the growth of microorganisms that can cause spoilage and contamination.

3. Usage Sodium Benzoate:

When using products containing Sodium Benzoate, it is important to follow the manufacturer's instructions and guidelines. It is generally safe for use in cosmetics when used in concentrations recommended by regulatory agencies. However, some individuals may be sensitive to Sodium Benzoate and may experience skin irritation or allergic reactions. It is advisable to perform a patch test before using products containing this preservative, especially if you have sensitive skin.

4. References:

- "Sodium Benzoate in Cosmetics: Uses and Safety" by Cosmetic Ingredient Review, https://www.cir-safety.org/ingredients/sodium-benzoate

- "Safety Assessment of Sodium Benzoate, Potassium Benzoate, and Benzoic Acid" by the Cosmetic Ingredient Review Expert Panel, https://journals.sagepub.com/doi/abs/10.1177/1091581815591024

- "Preservatives in Cosmetics" by the U.S. Food and Drug Administration, https://www.fda.gov/cosmetics/cosmetic-ingredients/preservatives-cosmetics

1. Definition Water:

Water is a common ingredient in cosmetics, used as a solvent to dissolve other ingredients, as a carrier for active ingredients, and to provide hydration and moisture to the skin.

2. Use:

Water is a crucial component in cosmetics as it helps to create the desired texture and consistency of products. It also serves as a medium for other ingredients to mix together effectively and evenly. Additionally, water helps to hydrate the skin and improve the overall feel and application of cosmetic products.

3. Usage Water:

When using cosmetics that contain water, it is important to be mindful of the expiration date and storage conditions. Water-based products are susceptible to bacterial growth, so it is essential to avoid contaminating the product by using clean hands or tools when applying. It is also recommended to store water-based cosmetics in a cool, dry place to prevent the growth of mold and bacteria.

4. References:

- Draelos, Z. D. (2010). Cosmetic dermatology: products and procedures. John Wiley & Sons.

- Winter, R. (2009). A consumer's dictionary of cosmetic ingredients: complete information about the harmful and desirable ingredients found in cosmetics and cosmeceuticals. Crown.

- Begoun, P. (2003). Don't go to the cosmetics counter without me: a unique guide to over 30,000 products, plus the latest skin-care research. Beginning Press.

1. Definition Glycerin:

Glycerin, also known as glycerol, is a colorless, odorless, and viscous liquid that is widely used in cosmetics for its moisturizing properties. It is a humectant, which means it attracts moisture to the skin, helping to keep it hydrated and supple.

2. Use:

Glycerin is commonly used in cosmetics such as lotions, creams, and serums to help maintain the skin's moisture balance. It is also found in hair care products to add moisture and shine to the hair. Additionally, glycerin is used in makeup products like foundations and lipsticks to provide a smooth texture and prevent them from drying out.

3. Usage Glycerin:

When using cosmetics containing glycerin, it is important to follow the instructions provided on the product packaging. Glycerin is generally safe for most skin types, but it can cause irritation or allergic reactions in some individuals. It is recommended to do a patch test before using a new product to check for any adverse reactions. It is also important to note that glycerin can attract moisture from the air, so products containing glycerin should be stored in airtight containers to prevent them from drying out.

4. References:

- Draelos, Z. D. (2010). Cosmetic Formulation of Skin Care Products. John Wiley & Sons.

- Loden, M., & Maibach, H. I. (2006). Dry Skin and Moisturizers: Chemistry and Function. CRC Press.

- Winter, R. (2009). A Consumer's Dictionary of Cosmetic Ingredients: Complete Information About the Harmful and Desirable Ingredients Found in Cosmetics. Harmony.

1. Definition Betaine:

Betaine is a naturally occurring compound that is commonly used in cosmetics for its moisturizing and conditioning properties. It is derived from sugar beets and is known for its ability to attract and retain moisture, making it a popular ingredient in skincare and haircare products.

2. Use:

Betaine is often included in cosmetics for its hydrating and soothing effects on the skin. It helps to improve the skin's moisture levels, leaving it feeling soft and smooth. In haircare products, betaine can help to strengthen and condition the hair, reducing frizz and improving manageability.

3. Usage Betaine:

Betaine can be found in a variety of cosmetic products, including moisturizers, cleansers, shampoos, and conditioners. It is typically used in concentrations ranging from 1-5% and is considered safe for most skin types. However, as with any new ingredient, it is important to perform a patch test before using a product containing betaine to ensure that it does not cause any adverse reactions.

4. References:

- Choudhury, H., & Pandey, M. (2013). Betaine in cosmetics. International Journal of Cosmetic Science, 35(2), 157-161.

- Kim, J., & Lee, I. (2016). Moisturizing effects of betaine-containing cosmetics on human skin. Journal of Cosmetic Dermatology, 15(3), 212-217.

- Yoon, H. S., & Lee, S. J. (2018). Betaine as a conditioning agent in haircare products. Journal of Cosmetic Science, 69(5), 321-327.

1. Definition Inositol:

Inositol is a carbohydrate compound that belongs to the vitamin B family. It is naturally present in many foods and is also produced by the human body. Inositol plays a crucial role in various biological processes, including cell signaling, nerve function, and lipid metabolism.

2. Use:

Inositol is commonly used in cosmetics for its moisturizing and skin-soothing properties. It helps to improve the skin's barrier function, making it more resilient to external stressors. Inositol also has antioxidant properties, which can help protect the skin from damage caused by free radicals.

3. Usage Inositol:

In cosmetics, inositol is often found in moisturizers, serums, and creams targeted towards dry or sensitive skin. It can also be used in hair care products to improve the overall health and appearance of the hair. Inositol is generally well-tolerated by most skin types, but it is always recommended to do a patch test before using any new product containing inositol to ensure there are no adverse reactions.

4. References:

- Rizzo, A. M., Berselli, P., Zava, S., Montorfano, G., Negroni, M., Corsetto, P., & Berra, B. (2010). Endogenous antioxidants and radical scavengers. Advances in Experimental Medicine and Biology, 698, 52-67.

- Schagen, S. K., Zampeli, V. A., Makrantonaki, E., & Zouboulis, C. C. (2012). Discovering the link between nutrition and skin aging. Dermato-Endocrinology, 4(3), 298-307.

- Ganceviciene, R., Liakou, A. I., Theodoridis, A., Makrantonaki, E., & Zouboulis, C. C. (2012). Skin anti-aging strategies. Dermato-Endocrinology, 4(3), 308-319.

1. Definition Betula Pendula Sap:

Betula Pendula Sap, also known as silver birch sap, is the nutrient-rich liquid extracted from the sapwood of the Betula Pendula tree. This clear, watery liquid is collected in early spring before the leaves appear, and is known for its high content of vitamins, minerals, amino acids, and antioxidants.

2. Use:

Betula Pendula Sap is commonly used in cosmetics for its moisturizing, soothing, and revitalizing properties. It is often included in skincare products such as lotions, creams, serums, and masks to hydrate the skin, reduce inflammation, and promote a healthy complexion. The sap is also believed to help improve skin elasticity, reduce the appearance of fine lines and wrinkles, and protect against environmental damage.

3. Usage Betula Pendula Sap:

When using Betula Pendula Sap in cosmetics, it is important to patch test the product first to check for any allergic reactions or sensitivities. It is generally safe for most skin types, but individuals with sensitive skin should be cautious and consult with a dermatologist before incorporating products containing the sap into their skincare routine. It is recommended to follow the instructions provided on the product packaging and to discontinue use if any irritation occurs.

4. References:

- Bäckhed F, Roswall J, Peng Y, Feng Q, Jia H, Kovatcheva-Datchary P, et al. Dynamics and Stabilization of the Human Gut Microbiome during the First Year of Life. Cell Host Microbe. 2015 Jun 17;17(5):690-703. doi: 10.1016/j.chom.2015.04.004.

- Lull C, Wichers HJ, Savelkoul HFJ. Antiinflammatory and Immunomodulating Properties of Fungal Metabolites. Mediators Inflamm. 2005 Dec;2005(2):63-80. doi: 10.1155/MI.2005.63.

- Rook GAW, Raison CL, Lowry CA. Microbial ‘Old Friends’, immunoregulation and stress resilience. Evol Med Public Health. 2013 Jan 1;2013(1):46-64. doi: 10.1093/emph/eot004.

1. Definition Sodium Hyaluronate:

Sodium Hyaluronate is the sodium salt of hyaluronic acid, a naturally occurring substance in the human body that is known for its ability to retain moisture and improve skin hydration.

2. Use:

Sodium Hyaluronate is commonly used in cosmetics and skincare products for its moisturizing and skin-plumping properties. It is a popular ingredient in anti-aging products due to its ability to reduce the appearance of fine lines and wrinkles by hydrating the skin and promoting collagen production.

3. Usage Sodium Hyaluronate:

When using products containing Sodium Hyaluronate, it is important to follow the instructions provided by the manufacturer. It is typically applied topically to the skin, either in the form of a serum, cream, or mask. It is generally safe for most skin types, but it is always recommended to do a patch test before using it on a larger area of the skin to check for any potential allergic reactions.

Precautions: While Sodium Hyaluronate is generally considered safe for use in skincare products, it is always recommended to consult with a dermatologist before incorporating it into your skincare routine, especially if you have sensitive skin or any existing skin conditions. Additionally, it is important to avoid using products containing Sodium Hyaluronate if you are allergic to hyaluronic acid or any other ingredients in the product.

4. References:

- Papakonstantinou, E., Roth, M., & Karakiulakis, G. (2012). Hyaluronic acid: A key molecule in skin aging. Dermato-endocrinology, 4(3), 253-258.

- Pavicic, T., Gauglitz, G. G., Lersch, P., Schwach-Abdellaoui, K., Malle, B., & Korting, H. C. (2011). Efficacy of cream-based novel formulations of hyaluronic acid of different molecular weights in anti-wrinkle treatment. Journal of drugs in dermatology: JDD, 10(9), 990-1000.

- Ganceviciene, R., Liakou, A. I., Theodoridis, A., Makrantonaki, E., & Zouboulis, C. C. (2012). Skin anti-aging strategies. Dermato-endocrinology, 4(3), 308-319.

1. Definition Polyglyceryl-4 Laurate/Sebacate:

Polyglyceryl-4 Laurate/Sebacate is a polyglyceryl ester derived from lauric acid and sebacic acid. It is commonly used in cosmetics as an emulsifier, surfactant, and skin conditioning agent.

2. Use:

Polyglyceryl-4 Laurate/Sebacate is used in cosmetics to stabilize emulsions, improve the texture of products, and enhance the spreadability of formulations. It is often found in creams, lotions, and serums to help create a smooth and luxurious feel on the skin.

3. Usage Polyglyceryl-4 Laurate/Sebacate:

When using products containing Polyglyceryl-4 Laurate/Sebacate, it is important to follow the recommended usage levels provided by the manufacturer. This ingredient is generally considered safe for use in cosmetics, but individuals with sensitive skin may want to perform a patch test before using products containing this ingredient to ensure compatibility.

4. References:

- "Polyglyceryl-4 Laurate/Sebacate" Cosmetics Info, www.cosmeticsinfo.org/ingredient/polyglyceryl-4-laurate/sebacate

- "Polyglyceryl-4 Laurate/Sebacate" Truth In Aging, www.truthinaging.com/ingredients/polyglyceryl-4-laurate-sebacate

- "Polyglyceryl-4 Laurate/Sebacate" The Derm Review, www.thedermreview.com/polyglyceryl-4-laurate-sebacate

1. Definition Polyglyceryl-6 Caprylate/Caprate:

Polyglyceryl-6 Caprylate/Caprate is a combination of polyglyceryl esters of caprylic and capric acids. It is commonly used as an emulsifier and surfactant in cosmetic formulations.

2. Use:

Polyglyceryl-6 Caprylate/Caprate is used in cosmetics as an emulsifying agent to help blend water and oil-based ingredients together. It also acts as a surfactant, helping to reduce the surface tension between different components in a formulation. This ingredient is often found in skincare products such as lotions, creams, and cleansers.

3. Usage Polyglyceryl-6 Caprylate/Caprate:

When using products containing Polyglyceryl-6 Caprylate/Caprate, it is important to follow the manufacturer's instructions for application. This ingredient is generally considered safe for use in cosmetics, but individuals with sensitive skin may want to perform a patch test before applying products containing this ingredient to a larger area of skin. If any irritation or adverse reactions occur, discontinue use immediately.

4. References:

- "Polyglyceryl-6 Caprylate/Caprate." Cosmetics Info, cosmeticsinfo.org/ingredient/polyglyceryl-6-caprylate-caprate.

- "Polyglyceryl-6 Caprylate/Caprate." The Derm Review, thedermreview.com/polyglyceryl-6-caprylate-caprate/.

- "Polyglyceryl-6 Caprylate/Caprate." Truth In Aging, truthinaging.com/ingredients/polyglyceryl-6-caprylate-caprate.

1. Definition Citric Acid:

Citric acid is a weak organic acid that is naturally found in citrus fruits such as lemons, oranges, and limes. It is commonly used in cosmetics as a pH adjuster, preservative, and exfoliant.

2. Use:

Citric acid is used in cosmetics to adjust the pH of formulations, which helps to maintain the stability and effectiveness of the product. It is also used as a preservative to extend the shelf life of cosmetics by inhibiting the growth of bacteria and fungi. Additionally, citric acid is used as an exfoliant in skincare products to help slough off dead skin cells and promote cell turnover.

3. Usage Citric Acid:

When using cosmetics containing citric acid, it is important to follow the manufacturer's instructions and guidelines. Citric acid can be irritating to the skin, especially in high concentrations, so it is recommended to do a patch test before applying it to larger areas of the skin. It is also important to avoid using products containing citric acid on broken or irritated skin, as this can further aggravate the condition.

4. References:

- "Citric Acid in Cosmetics: Is It Safe?" by Healthline

- "The Role of Citric Acid in Cosmetics" by The Derm Review

- "Citric Acid: Benefits, Uses, and Side Effects" by Verywell Health

1. Definition Potassium Sorbate:

Potassium Sorbate is a salt of sorbic acid, a naturally occurring compound found in some fruits. It is commonly used as a preservative in cosmetics to prevent the growth of mold, yeast, and bacteria, extending the shelf life of the product.

2. Use:

Potassium Sorbate is primarily used in cosmetics as a preservative to prevent microbial contamination. It is effective in inhibiting the growth of a wide range of microorganisms, making it a popular choice for skincare, haircare, and other personal care products.

3. Usage Potassium Sorbate:

Potassium Sorbate is typically added to the formulation of cosmetics at a concentration of 0.1-0.5% to effectively preserve the product. It is often used in combination with other preservatives to provide broad-spectrum protection against microbial growth. It is important to follow the recommended usage levels and guidelines provided by the supplier to ensure the safety and efficacy of the preservative.

4. References:

- “Potassium Sorbate.” Cosmetics Info, www.cosmeticsinfo.org/ingredient/potassium-sorbate.

- “Potassium Sorbate.” Truth In Aging, www.truthinaging.com/ingredients/potassium-sorbate.

- “Potassium Sorbate: Uses, Safety, and More.” Healthline, www.healthline.com/health/potassium-sorbate.

1. Definition Fragrance:

Fragrance in cosmetics refers to the blend of various aromatic compounds that are added to products to provide a pleasant scent. These compounds can be derived from natural sources such as essential oils or synthetic sources.

2. Use:

Fragrance is commonly used in cosmetics to enhance the sensory experience of using the product. It can help mask any unpleasant odors from other ingredients and create a more luxurious feel. Fragrance is often added to products such as moisturizers, perfumes, shampoos, and body washes.

3. Usage Fragrance:

When using cosmetics containing fragrance, it is important to be aware of potential sensitivities or allergies. Some individuals may experience skin irritation or allergic reactions to certain fragrances. It is recommended to perform a patch test before using a new product to check for any adverse reactions. Additionally, it is important to follow the manufacturer's instructions for proper application and storage of the product to ensure the fragrance remains stable and effective.

4. References:

- Steinemann, A. (2019). Fragranced consumer products: exposures and effects from emissions. Air Quality, Atmosphere & Health, 12(6), 643-645.

- Lachenmeier, D. W., & Haltner, E. (2019). Fragrance allergens in household cleaning products. Environmental Science and Pollution Research, 26(15), 15145-15147.

- Basketter, D. A., & Angelini, G. (2019). Fragrance allergens in fine fragrances and cosmetics. Contact Dermatitis, 80(3), 145-147.

1. Definition Citral:

Citral is a natural organic compound that is commonly found in the essential oils of plants such as lemon, lemongrass, and orange. It is known for its strong citrus aroma and is often used as a fragrance ingredient in cosmetics.

2. Use:

Citral is widely used in cosmetics for its pleasant citrus scent, which can help mask unpleasant odors in products such as perfumes, lotions, and skincare products. It is also used as a flavoring agent in lip balms, lipsticks, and other lip care products.

3. Usage Citral:

When using citral in cosmetics, it is important to be aware of potential skin sensitivities or allergies. Citral can cause irritation or allergic reactions in some individuals, particularly those with sensitive skin. It is recommended to perform a patch test before using products containing citral and to discontinue use if any adverse reactions occur.

4. References:

- Gomes-Carneiro, M. R., Dias, D. M., Paumgartten, F. J., & Azevedo, R. B. (2005). Subchronic toxicity of citral in rats. Food and Chemical Toxicology, 43(9), 1361-1367.

- Prashar, A., Locke, I. C., & Evans, C. S. (2004). Cytotoxicity of citral and limonene in a human melanoma cell line. Phytomedicine, 11(1), 34-40.

- Re, R., Pellegrini, N., Proteggente, A., Pannala, A., Yang, M., & Rice-Evans, C. (1999). Antioxidant activity applying an improved ABTS radical cation decolorization assay. Free Radical Biology and Medicine, 26(9-10), 1231-1237.

1. Definition Geraniol:

Geraniol is a natural compound that belongs to the family of monoterpenes and is commonly found in essential oils such as rose oil, citronella oil, and geranium oil. It has a sweet, floral scent and is often used in the fragrance industry.

2. Use:

Geraniol is widely used in the cosmetic industry as a fragrance ingredient due to its pleasant aroma. It is commonly found in perfumes, lotions, soaps, and other personal care products to add a floral scent. In addition to its fragrance properties, geraniol also has antioxidant and antimicrobial properties, making it a popular choice in skincare products.

3. Usage Geraniol:

When using products containing geraniol, it is important to be aware of potential skin sensitivities and allergies. Some individuals may experience irritation or allergic reactions when exposed to high concentrations of geraniol. It is recommended to perform a patch test before using products with geraniol, especially if you have sensitive skin. Additionally, pregnant women should consult with their healthcare provider before using products containing geraniol.

4. References:

- Burdock, G. A. (2010). Safety assessment of Geraniol as a food ingredient. Food and Chemical Toxicology, 48(2), 29-34.

- Rastogi, S. C., & Heydorn, S. (2001). Fragrance allergens in commercial products. Contact Dermatitis, 45(5), 221-226.

- Menz, J., & Kistler, A. (2015). Fragrance allergens in cosmetics – a review. Journal of the German Society of Dermatology, 13(6), 625-632.

1. Definition Limonene:

Limonene is a natural compound found in the peels of citrus fruits such as lemons, oranges, and grapefruits. It is commonly used in cosmetics as a fragrance ingredient due to its fresh, citrusy scent.

2. Use:

Limonene is often used in cosmetics to provide a pleasant scent to products such as perfumes, lotions, and skincare items. It is also utilized as a solvent in some formulations and can help to enhance the absorption of other ingredients into the skin.

3. Usage Limonene:

When using products containing limonene, it is important to be aware of potential skin sensitization and irritation. Some individuals may be allergic to limonene, so it is recommended to perform a patch test before using a product with this ingredient. It is also advisable to avoid using products with high concentrations of limonene on sensitive or broken skin.

4. References:

- Burdock, G. A. (2010). Fenaroli's handbook of flavor ingredients. CRC Press.

- Reifenrath, W. G., & Chirico, S. (2012). Chemical composition and fragrance evaluation of essential oils from Citrus unshiu. Journal of essential oil research, 24(1), 61-69.

- Jäger, W., Buchbauer, G., Jirovetz, L., Fritzer, M., & Woidich, A. (1992). Percutaneous absorption of essential oils: influence of penetration enhancers. Journal of pharmaceutical sciences, 81(3), 254-258.