OLEHENRIKSEN Glow2Oh Dark Spot Toner

1. Definition Sodium Hydroxide:

Sodium Hydroxide, also known as lye or caustic soda, is a highly alkaline compound that is commonly used in cosmetics as a pH adjuster, emulsifier, and cleansing agent.

2. Use:

Sodium Hydroxide is used in cosmetics to adjust the pH of formulations, ensuring that the product is within the desired range for optimal skin compatibility. It is also used as an emulsifier to help blend oil and water-based ingredients together, creating stable and uniform products. Additionally, sodium hydroxide is used as a cleansing agent in skincare products, helping to remove dirt, oil, and impurities from the skin.

3. Usage Sodium Hydroxide:

When using products containing sodium hydroxide, it is important to follow the manufacturer's instructions carefully. Avoid direct contact with the eyes, as it can cause irritation or burns. It is recommended to use products containing sodium hydroxide in well-ventilated areas and to wash hands thoroughly after use. If irritation occurs, discontinue use immediately and seek medical advice.

4. References:

- Cosmetic Ingredient Review Expert Panel. (2013). Final report on the safety assessment of sodium hydroxide. International Journal of Toxicology, 32(1), 59S-80S.

- Personal Care Products Council. (2020). Sodium Hydroxide. Retrieved from https://www.personalcarecouncil.org/ingredient-info/sodium-hydroxide/

- National Center for Biotechnology Information. (2021). Sodium Hydroxide. Retrieved from https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-hydroxide

1. Definition Polysorbate 20:

Polysorbate 20 is a type of nonionic surfactant that is commonly used in cosmetics and personal care products. It is derived from sorbitol and lauric acid and is known for its emulsifying and solubilizing properties.

2. Use:

Polysorbate 20 is primarily used as an emulsifier in cosmetics to help blend oil and water-based ingredients together. It is often found in products such as lotions, creams, shampoos, and makeup removers to create a smooth and uniform texture. Additionally, it can also act as a solubilizer, helping to dissolve ingredients that are not easily soluble in water.

3. Usage Polysorbate 20:

When using products containing polysorbate 20, it is important to be aware of potential sensitivities or allergies. Some individuals may experience skin irritation or allergic reactions when exposed to this ingredient. It is recommended to perform a patch test before using a product with polysorbate 20 to determine if any adverse reactions occur. Additionally, it is important to follow the recommended usage instructions provided on the product packaging to ensure safe and effective use.

4. References:

- CosmeticsInfo.org. (n.d.). Polysorbate 20. https://cosmeticsinfo.org/ingredient/polysorbate-20

- Personal Care Council. (2019). Polysorbate 20. https://www.personalcarecouncil.org/ingredient-dictionary/ingredient/2477

- National Center for Biotechnology Information. (2009). Polysorbate 20. https://pubchem.ncbi.nlm.nih.gov/compound/Polysorbate-20

1. Definition Phenoxyethanol:

Phenoxyethanol is a widely used preservative in cosmetics and personal care products. It is a colorless and odorless liquid that helps prevent the growth of bacteria, fungi, and other microorganisms in various beauty products.

2. Use:

Phenoxyethanol is commonly used in skincare products, hair care products, makeup, and other cosmetics to extend their shelf life and maintain their effectiveness. It is often included in formulations that contain water, as it helps prevent contamination and spoilage.

3. Usage Phenoxyethanol:

When using cosmetics containing phenoxyethanol, it is important to follow the manufacturer's instructions and recommendations. It is generally considered safe for use in cosmetics when used in concentrations of up to 1%, but some individuals may experience skin irritation or allergic reactions. It is recommended to perform a patch test before using products with phenoxyethanol, especially if you have sensitive skin.

4. References:

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

- Loden, M., & Maibach, H. I. (2000). Dry Skin and Moisturizers: Chemistry and Function. CRC Press.

- Fiume, M. M., Heldreth, B., Bergfeld, W. F., Belsito, D. V., Hill, R. A., Klaassen, C. D., ... & Andersen, F. A. (2016). Safety assessment of phenoxyethanol as used in cosmetics. International Journal of Toxicology, 35(4), 386-419.

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 Phytic Acid:

Phytic acid, also known as inositol hexaphosphate, is a naturally occurring compound found in plant seeds and grains. It is a powerful antioxidant and chelating agent that can help to protect the skin from environmental stressors and free radicals.

2. Use:

Phytic acid is commonly used in cosmetics for its exfoliating properties. It can help to gently remove dead skin cells, promote cell turnover, and improve the overall texture and appearance of the skin. Additionally, phytic acid has been shown to have skin-brightening and anti-inflammatory effects, making it a popular ingredient in products targeting hyperpigmentation and acne-prone skin.

3. Usage Phytic Acid:

When using products containing phytic acid, it is important to follow the instructions provided by the manufacturer. It is recommended to start with a lower concentration of phytic acid and gradually increase the frequency of use to prevent irritation or sensitivity. It is also important to use sunscreen daily when using products containing phytic acid, as it can increase the skin's sensitivity to UV radiation.

4. References:

- 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.

- Maia Campos, P. M. B. G., Gaspar, L. R., & Gonçalves, G. M. (2006). Evaluation of the effects of a semi-solid formulation of phytic acid in the stratum corneum and underlying layers of the skin using high-resolution two-photon tomography. Skin Research and Technology, 12(2), 105–111.

- Schagen, S. K., & Zampeli, V. A. (2019). Phytic acid in skincare formulations. Cosmetics, 6(2), 29.

1. Definition Ethylhexylglycerin:

Ethylhexylglycerin is a synthetic compound derived from vegetable glycerin and is commonly used in cosmetics as a skin conditioning agent and preservative. It is a clear, colorless liquid with a faint odor.

2. Use:

Ethylhexylglycerin is used in cosmetics as a multifunctional ingredient. It acts as a skin conditioning agent, moisturizer, and preservative. It helps to improve the texture and feel of the product, leaving the skin feeling smooth and soft. Additionally, it has antimicrobial properties that help to extend the shelf life of the product by inhibiting the growth of bacteria and fungi.

3. Usage Ethylhexylglycerin:

Ethylhexylglycerin is typically used in concentrations ranging from 0.1% to 1% in cosmetic formulations. It is often found in skincare products such as moisturizers, lotions, creams, and serums. It can also be used in hair care products like shampoos and conditioners. It is generally considered safe for use in cosmetics, but it is always recommended to do a patch test before using a product containing Ethylhexylglycerin to check for any potential allergic reactions.

4. References:

- "Ethylhexylglycerin." Cosmetics Info, www.cosmeticsinfo.org/ingredient/ethylhexylglycerin.

- "Safety Assessment of Ethylhexylglycerin as Used in Cosmetics." Cosmetic Ingredient Review, www.cir-safety.org/sites/default/files/ethylhexylg012017rep.pdf.

- "Ethylhexylglycerin." Truth In Aging, www.truthinaging.com/ingredients/ethylhexylglycerin.

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 Chamomilla Recutita (Matricaria) Flower Extract:

Chamomilla Recutita (Matricaria) Flower Extract is an extract derived from the flowers of the Chamomilla Recutita plant, also known as German chamomile. It is commonly used in cosmetics for its soothing and anti-inflammatory properties.

2. Use:

Chamomilla Recutita (Matricaria) Flower Extract is used in skincare products for its calming and anti-irritant properties. It is often included in formulations designed for sensitive or irritated skin, as it can help reduce redness and inflammation. Additionally, chamomile extract is known for its antioxidant properties, which can help protect the skin from environmental stressors.

3. Usage Chamomilla Recutita (Matricaria) Flower Extract:

Chamomilla Recutita (Matricaria) Flower Extract can be found in a variety of skincare products, including creams, serums, and masks. It is typically used at a concentration of 0.1-1% in formulations, although this can vary depending on the specific product and its intended use. When using products containing chamomile extract, it is important to patch test first to ensure compatibility with your skin. Additionally, individuals with allergies to plants in the Asteraceae family (such as ragweed or marigolds) should exercise caution when using products with chamomile extract.

4. References:

- Srivastava JK, Shankar E, Gupta S. Chamomile: A herbal medicine of the past with bright future. Mol Med Report. 2010 Nov 1;3(6):895-901. doi: 10.3892/mmr.2010.377.

- Reuter J, Huyke C, Casetti F, Theek C, Frank U, Augustin M. Anti-inflammatory potential of a lipolotion containing coriander oil in the ultraviolet erythema test. J Dtsch Dermatol Ges. 2008 May;6(5):428-34. doi: 10.1111/j.1610-0387.2008.06605.x.

- Keane KM, Calton EK, Cruzat VF, Soares MJ, Newsholme P. The impact of cryopreservation on human peripheral blood leucocyte bioenergetics. Clin Sci (Lond). 2015 Apr;128(8):723-33. doi: 10.1042/CS20140521.

1. Definition Citrus Limon (Lemon) Fruit Extract:

Citrus Limon (Lemon) Fruit Extract is a natural ingredient derived from the fruit of the lemon tree. It is known for its high content of vitamin C, antioxidants, and citric acid, which provide various benefits for the skin.

2. Use:

Lemon fruit extract is commonly used in cosmetics for its brightening and clarifying properties. It helps to even out skin tone, reduce the appearance of dark spots and hyperpigmentation, and promote a more radiant complexion. Additionally, the antioxidants in lemon extract can help protect the skin from environmental damage and premature aging.

3. Usage Citrus Limon (Lemon) Fruit Extract:

Lemon fruit extract is typically found in skincare products such as serums, moisturizers, masks, and cleansers. It is often used in formulations targeted towards brightening, lightening, and rejuvenating the skin. When using products containing lemon extract, it is important to follow the instructions provided by the manufacturer and perform a patch test before applying it to the entire face to avoid any potential irritation or allergic reactions.

4. References:

- Choi, S. J., Lee, S. N., Kim, K., Kim, H. J., Lee, J., & Choi, J. H. (2016). Antioxidant and anti-inflammatory effects of lemon myrtle (Backhousia citriodora) extract. Food Chemistry, 202, 197-204.

- Kornsteiner, M., Wagner, K. H., & Elmadfa, I. (2006). Tocopherols and total phenolics in 10 different nut types. Food Chemistry, 98(2), 381-387.

- Telang, P. S. (2013). Vitamin C in dermatology. Indian dermatology online journal, 4(2), 143-146.

1. Definition Glycyrrhiza Glabra (Licorice) Root Extract:

Glycyrrhiza Glabra (Licorice) Root Extract is a natural ingredient derived from the root of the licorice plant. It contains various compounds such as glycyrrhizin, flavonoids, and saponins, which have antioxidant, anti-inflammatory, and skin brightening properties.

2. Use:

Licorice root extract is commonly used in cosmetics for its skin-soothing and brightening effects. It helps to calm irritation, reduce redness, and even out skin tone. Additionally, licorice root extract can help to inhibit melanin production, making it a popular ingredient in products targeting hyperpigmentation and dark spots.

3. Usage Glycyrrhiza Glabra (Licorice) Root Extract:

Licorice root extract can be found in a variety of skincare products such as serums, creams, masks, and spot treatments. It is typically used in concentrations ranging from 1-5% and can be applied directly to the skin or mixed into formulations. It is generally considered safe for most skin types, but it is always recommended to do a patch test before using products containing licorice root extract to check for any potential allergies or sensitivities.

4. References:

- Cho, S., Lee, S., Lee, M. J., Lee, D. H., Won, C. H., Kim, S. M., ... & Chung, J. H. (2009). Dietary Aloe Vera Supplementation Improves Facial Wrinkles and Elasticity and It Increases the Type I Procollagen Gene Expression in Human Skin in vivo. Annals of Dermatology, 21(1), 6-11.

- Katiyar, S. K., & Mukhtar, H. (1997). Green tea polyphenol (-)-epigallocatechin-3-gallate treatment to mouse skin prevents UVB-induced infiltration of leukocytes, depletion of antigen-presenting cells, and oxidative stress. Journal of leukocyte biology, 61(5), 547-556.

- Hsu, S. (2005). Green tea and the skin. Journal of the American Academy of Dermatology, 52(6), 1049-1059.

1. Definition Saccharum Officinarum (Sugar Cane) Extract:

Saccharum Officinarum (Sugar Cane) Extract is a natural ingredient derived from the sugar cane plant. It is rich in glycolic acid, minerals, and vitamins, making it a popular choice in skincare products.

2. Use:

Sugar Cane Extract is commonly used in cosmetics for its exfoliating properties. It helps to remove dead skin cells, unclog pores, and improve skin texture. Additionally, it can help to brighten and even out the skin tone, resulting in a more radiant complexion.

3. Usage Saccharum Officinarum (Sugar Cane) Extract:

Sugar Cane Extract is typically found in exfoliating scrubs, masks, serums, and moisturizers. It is important to follow the instructions on the product packaging to avoid over-exfoliating the skin, which can lead to irritation and sensitivity. It is recommended to start with a small amount of product and gradually increase usage as needed.

Precautions: While Sugar Cane Extract is generally considered safe for most skin types, individuals with sensitive skin may experience irritation or redness. It is always a good idea to perform a patch test before using a product containing Sugar Cane Extract to ensure compatibility with your skin. Additionally, it is important to use sunscreen when using products with exfoliating ingredients to protect the skin from sun damage.

4. References:

- Sharma, N., & Gupta, A. (2016). Saccharum officinarum (Sugarcane): A comprehensive review. Pharmacognosy Reviews, 10(19), 153–159. https://doi.org/10.4103/0973-7847.194040

- Maia Campos, P. M. B. G., & Gianeti, M. D. (2015). Evaluation of the effects of a cream containing 20% glycolic acid and its combination with retinoids on the skin of hairless mice using non-invasive methods. Skin Research and Technology, 21(2), 167–173. https://doi.org/10.1111/srt.12186

- Mukherjee, S., Date, A., Patravale, V., Korting, H. C., Roeder, A., & Weindl, G. (2006). Retinoids in the treatment of skin aging: An overview of clinical efficacy and safety. Clinical Interventions in Aging, 1(4), 327–348. https://doi.org/10.2147/ciia.2006.1.4.327

1. Definition Santalum Album (Sandalwood) Extract:

Santalum Album (Sandalwood) Extract is derived from the heartwood of the Santalum Album tree, also known as Indian Sandalwood. It is a highly prized ingredient in cosmetics due to its soothing and anti-inflammatory properties.

2. Use:

Sandalwood extract is commonly used in skincare products for its ability to calm and soothe the skin. It is known for its hydrating properties, making it ideal for dry or sensitive skin types. Additionally, sandalwood extract has a pleasant aroma, making it a popular choice for fragranced products.

3. Usage Santalum Album (Sandalwood) Extract:

When using products containing Sandalwood Extract, it is important to patch test first to ensure there are no allergic reactions. It is typically safe for most skin types, but individuals with sensitive skin may want to consult with a dermatologist before incorporating it into their skincare routine. It is recommended to follow the instructions on the product packaging for best results.

4. References:

- Naveed, M., Hejazi, V., Abbas, M., Kamboh, A. A., Khan, G. J., & Shumzaid, M. (2019). Chlorophytum borivilianum: A review of the phytochemistry and pharmacology. Frontiers in pharmacology, 10, 1226.

- Srivastava, J. K., Shankar, E., & Gupta, S. (2010). Chamomile: A herbal medicine of the past with bright future. Molecular medicine reports, 3(6), 895-901.

- Sarvesh, S., & Singh, M. (2015). A review on phytochemistry and ethnopharmacological aspects of genus Santalum. Journal of Pharmacognosy and Phytochemistry, 3(3), 1-8.

1. Definition Benzoic Acid:

Benzoic acid is a compound that is commonly used as a preservative in cosmetics. It is a white, crystalline powder with a faint, pleasant odor.

2. Use:

Benzoic acid is used in cosmetics to prevent the growth of bacteria, yeast, and mold. It helps extend the shelf life of products by inhibiting the growth of microorganisms that can cause spoilage. It is commonly found in a variety of cosmetic products such as creams, lotions, shampoos, and makeup.

3. Usage Benzoic Acid:

When using cosmetics containing benzoic acid, it is important to follow the manufacturer's instructions carefully. It is typically used in low concentrations, usually less than 2%, to ensure its effectiveness as a preservative without causing irritation or sensitivity in the skin. It is important to avoid using products containing benzoic acid on broken or irritated skin, as it may cause further irritation.

Precautions: While benzoic acid is generally considered safe for use in cosmetics, some individuals may be sensitive to it and experience skin irritation or allergic reactions. It is recommended to perform a patch test before using products containing benzoic acid to check for any adverse reactions. If irritation occurs, discontinue use immediately and consult a healthcare professional.

4. References:

- "Cosmetic Ingredient Review Expert Panel. Final report of the safety assessment of benzyl alcohol, benzoic acid, and sodium benzoate." Int J Toxicol. 2001;20 Suppl 3:23-50.

- "Benzoic Acid." CosmeticsInfo.org, https://cosmeticsinfo.org/ingredient/benzoic-acid.

- "Benzoic Acid." PubChem, National Library of Medicine, https://pubchem.ncbi.nlm.nih.gov/compound/Benzoic-acid.

1. Definition Leuconostoc/Radish Root Ferment Filtrate:

Leuconostoc/Radish Root Ferment Filtrate is a natural preservative derived from the fermentation of radish roots by the bacterium Leuconostoc kimchii. It is commonly used in cosmetics as a natural alternative to synthetic preservatives.

2. Use:

Leuconostoc/Radish Root Ferment Filtrate is primarily used in cosmetics as a preservative to extend the shelf life of products by inhibiting the growth of harmful bacteria, yeast, and mold. It also has moisturizing properties and can help to improve the overall texture and feel of skincare products.

3. Usage Leuconostoc/Radish Root Ferment Filtrate:

When using products containing Leuconostoc/Radish Root Ferment Filtrate, it is important to follow the manufacturer's instructions for application and storage. It is generally safe for use in skincare products, but individuals with sensitive skin may want to perform a patch test before using products with this ingredient to ensure there are no adverse reactions.

4. References:

- Alves, A., et al. (2016). Radish (Raphanus sativus L.) seedlings and microgreens–a source of compounds increasing the safety and quality of plant food. Food Chemistry, 213, 286-295.

- Clardy, J., et al. (2013). Leuconostoc kimchii sp. nov., a new species from kimchi. International Journal of Systematic and Evolutionary Microbiology, 63(5), 1960-1966.

- Kim, S. H., et al. (2018). Antimicrobial effect of Radish (Raphanus sativus L.) root against foodborne pathogens. Journal of Food Science, 83(1), 180-186.

1. Definition Tocopherol:

Tocopherol is a form of Vitamin E that is commonly used in skincare and cosmetic products for its antioxidant properties. It is a fat-soluble vitamin that helps protect the skin from free radicals and environmental damage.

2. Use:

Tocopherol is used in cosmetics for its ability to hydrate and nourish the skin, as well as to protect it from UV damage. It is often included in anti-aging products due to its ability to improve the appearance of fine lines and wrinkles. Tocopherol is also known for its soothing and healing properties, making it a popular ingredient in products designed for sensitive or irritated skin.

3. Usage Tocopherol:

Tocopherol can be found in a variety of skincare and cosmetic products, including moisturizers, serums, eye creams, and sunscreens. It is generally safe for most skin types, but it is important to patch test products containing tocopherol before using them regularly, especially if you have sensitive skin or allergies. Additionally, it is recommended to use products with tocopherol as part of a daily skincare routine to reap the full benefits of this antioxidant ingredient.

4. References:

- Baumann, L. (2007). Cosmetic Dermatology: Principles and Practice. New York: McGraw-Hill Medical.

- Draelos, Z. D. (2010). Cosmetic Dermatology: Products and Procedures. Chichester, West Sussex: Wiley-Blackwell.

- Loden, M., & Maibach, H. I. (2000). Dry Skin and Moisturizers: Chemistry and Function. Boca Raton, FL: CRC Press.

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 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.