Ingredient Explanation
Other Names: Aqua; H2O; Eau; Aqueous; Acqua
Function: Solvent
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.
Other Names: Glycerine; Glycerin; Pflanzliches Glycerin; 1,2,3-Propanetriol
Function: Solvent, Perfuming, Fragrance, Humectant, Viscosity Decreasing Agent, Hair Conditioning, Skin Protecting, Denaturant
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.
Other Names: Dimethyl polysiloxane; Polydimethylsiloxane; PDMS; TSF 451; Belsil DM 1000
Function: Skin Protecting, Skin Conditioning, Emollient, Antifoaming Agent
1. Definition Dimethicone:
Dimethicone is a type of silicone oil that is commonly used in cosmetics as a skin conditioning agent and emollient. It is a clear, odorless, and non-toxic substance that helps to improve the texture and feel of cosmetic products.
2. Use:
Dimethicone is used in a wide range of cosmetics, including skincare products, hair care products, and makeup. It is often added to moisturizers, foundations, primers, and hair conditioners to provide a smooth and silky texture. Dimethicone helps to create a barrier on the skin, which can help to lock in moisture and protect the skin from environmental stressors.
3. Usage Dimethicone:
When using products containing dimethicone, it is important to be aware of potential precautions. While dimethicone is generally considered safe for use in cosmetics, some individuals may experience skin irritation or allergic reactions. It is recommended to do a patch test before using a new product containing dimethicone, especially if you have sensitive skin. Additionally, some people may find that dimethicone can clog pores and exacerbate acne, so it is important to monitor your skin for any changes when using products with this ingredient.
4. References:
- Lanigan, R. S., & Yamarik, T. A. (2002). Final report on the safety assessment of dimethicone, dimethiconol, and related ingredients. International journal of toxicology, 21(1), 7-41.
- Draelos, Z. D. (2010). Cosmetic vehicle efficacy. Dermatologic therapy, 23(4), 314-317.
- Fiume, M. M., Bergfeld, W. F., Belsito, D. V., Hill, R. A., Klaassen, C. D., Liebler, D., ... & Andersen, F. A. (2016). Safety assessment of dimethicone crosspolymers as used in cosmetics. International journal of toxicology, 35(1_suppl), 5S-24S.
Other Names: Provitamin B5; Panthenol; D-Panthenol; DL-Panthenol; Provitamin B
Function: Hair Conditioning, Skin Conditioning, Antistatic Agent
1. Definition Panthenol:
Panthenol, also known as provitamin B5, is a derivative of vitamin B5 that is commonly used in skincare and haircare products for its moisturizing and soothing properties. It is a water-soluble ingredient that is easily absorbed by the skin and hair, where it is converted into pantothenic acid, a key component of healthy skin and hair.
2. Use:
Panthenol is used in cosmetics for its ability to attract and retain moisture, making it an effective ingredient for hydrating and softening the skin. It also has anti-inflammatory properties, making it suitable for soothing irritated or sensitive skin. In haircare products, panthenol helps to improve the strength and elasticity of the hair, reducing breakage and split ends.
3. Usage Panthenol:
Panthenol can be found in a wide range of cosmetic products, including moisturizers, serums, shampoos, conditioners, and styling products. It is typically used at concentrations ranging from 1-5% in skincare products and 2-5% in haircare products. Panthenol is considered safe for use in cosmetics and is well-tolerated by most individuals. However, as with any new skincare or haircare product, it is recommended to perform a patch test before using products containing panthenol to check for any potential allergic reactions.
4. References:
- Draelos, Z. D. (2010). Cosmetic Formulation of Skin Care Products. CRC Press.
- Baumann, L. (2009). Cosmetic Dermatology: Principles and Practice. McGraw Hill Professional.
- Fiume, M. M., Bergfeld, W. F., Belsito, D. V., Hill, R. A., Klaassen, C. D., Liebler, D. C., ... & Andersen, F. A. (2016). Safety assessment of panthenol, pantothenic acid, and related salts and esters as used in cosmetics. International Journal of Toxicology, 35(2), 42S-61S.
Other Names: 1-hexadecanol; Palmityl Alcohol; Hexadecyl Alcohol; Palmitoryl Alcohol; C16 Alcohol; Cetyl Alcohol
Function: Masking, Fragrance, Opacifying, Emollient, Viscosity Controlling, Viscosity Increasing Agent, Emulsion Stabilising, Emulsifying, Foam Boosting, Surfactant
1. Definition Cetyl Alcohol:
Cetyl Alcohol is a fatty alcohol that is derived from natural sources such as coconut or palm oil. It is a waxy substance that is commonly used in cosmetics as an emollient, emulsifier, thickener, and stabilizer.
2. Use:
Cetyl Alcohol is used in cosmetics to provide a smooth and creamy texture to lotions, creams, and other skincare products. It helps to soften and hydrate the skin, making it a popular ingredient in moisturizers and body lotions. Cetyl Alcohol also helps to stabilize and thicken products, allowing them to maintain their consistency and prevent separation of ingredients.
3. Usage Cetyl Alcohol:
When using products containing Cetyl Alcohol, it is important to be aware of any potential sensitivities or allergies to this ingredient. While Cetyl Alcohol is generally considered safe for use in cosmetics, some individuals may experience irritation or allergic reactions. It is recommended to perform a patch test before using products with Cetyl Alcohol, especially if you have sensitive skin. Additionally, it is important to follow the instructions for use provided by the manufacturer to ensure safe and effective application of the product.
4. References:
- "Cetyl Alcohol" by Cosmetics Info (https://cosmeticsinfo.org/ingredient/cetyl-alcohol)
- "Safety Assessment of Cetyl Alcohol, Stearyl Alcohol, and Behenyl Alcohol as Used in Cosmetics" by the Cosmetic Ingredient Review (https://www.cir-safety.org/sites/default/files/final_report_alcohols.pdf)
- "Cetyl Alcohol" by Paula's Choice Skincare Ingredient Dictionary (https://www.paulaschoice.com/ingredient-dictionary/emollients/cetyl-alcohol.html)
Function: Solvent, Masking, Fragrance, Viscosity Decreasing Agent, Preservative, External Analgesic
1. Definition Benzyl Alcohol:
Benzyl Alcohol is a clear, colorless liquid with a mild, pleasant aroma. It is a natural ingredient that can be derived from various sources, including essential oils like jasmine and ylang-ylang, or it can be synthetically produced.
2. Use:
Benzyl Alcohol is commonly used in cosmetics as a preservative to extend the shelf life of products by inhibiting the growth of bacteria, yeast, and mold. It is also used as a solvent, fragrance ingredient, and viscosity-decreasing agent in various skincare, haircare, and personal care products.
3. Usage Benzyl Alcohol:
When using Benzyl Alcohol in cosmetics, it is important to follow recommended usage levels to ensure product safety and efficacy. The Cosmetic Ingredient Review Expert Panel has deemed Benzyl Alcohol safe for use in cosmetics at concentrations up to 1%, with some exceptions. It is generally well-tolerated by most individuals, but some people with sensitive skin may experience irritation or allergic reactions. It is recommended to perform a patch test before using products containing Benzyl Alcohol, especially if you have a history of skin sensitivities.
4. References:
- Cosmetic Ingredient Review Expert Panel. (2008). Final report on the safety assessment of Benzyl Alcohol, Benzoic Acid, and Sodium Benzoate. International Journal of Toxicology, 27(1), 1-23.
- Personal Care Products Council. (2019). Benzyl Alcohol. Retrieved from https://www.cosmeticsinfo.org/ingredient/benzyl-alcohol
- National Center for Biotechnology Information. (2021). PubChem Compound Summary for CID 244, Benzyl Alcohol. Retrieved from https://pubchem.ncbi.nlm.nih.gov/compound/Benzyl-alcohol
Other Names: Petrolatum; Vaseline; Soft Paraffin; Petrolatum base; Petroleum Jelly
Function: Hair Conditioning, Skin Protecting, Uv Absorber, Emollient, Skin-Conditioning Agent - Occlusive, Moisturising
1. Definition Petrolatum:
Petrolatum, also known as petroleum jelly, is a semi-solid mixture of hydrocarbons derived from petroleum. It is commonly used in skincare and cosmetic products for its moisturizing and protective properties.
2. Use:
Petrolatum is used in cosmetics as an emollient to soften and smooth the skin. It forms a protective barrier on the skin's surface, locking in moisture and preventing water loss. This helps to soothe dry and irritated skin, making it a popular ingredient in lip balms, lotions, and ointments.
3. Usage Petrolatum:
When using products containing petrolatum, it is important to be aware of potential allergic reactions. Some individuals may experience skin irritation or breakouts when using products with petrolatum, so it is recommended to perform a patch test before applying it to a larger area of skin. Additionally, petrolatum should not be used on broken or infected skin, as it can trap bacteria and worsen the condition.
4. References:
- Draelos, Z. D. (2010). Cosmetic Formulation of Skin Care Products. CRC Press.
- Baumann, L. (2009). Cosmetic Dermatology: Principles and Practice. McGraw-Hill Education.
- Loden, M., & Maibach, H. I. (1999). Dry Skin and Moisturizers: Chemistry and Function. CRC Press.
Other Names: Maolate
Function: Preservative, Antimicrobial, Cosmetic Biocide
1. Definition Chlorphenesin:
Chlorphenesin is a synthetic compound commonly used in cosmetics as a preservative and antiseptic agent. It is a white crystalline powder with a mild, pleasant odor.
2. Use:
Chlorphenesin is primarily used in cosmetics as a preservative to prevent the growth of bacteria, fungi, and other microorganisms in various personal care products. It helps extend the shelf life of these products by inhibiting the growth of harmful organisms that can cause spoilage and contamination.
3. Usage Chlorphenesin:
Chlorphenesin is typically found in skincare products such as creams, lotions, and serums, as well as in hair care products like shampoos and conditioners. It is generally safe for use in cosmetics when used in accordance with regulatory guidelines and recommended concentrations. However, it is important to follow the manufacturer's instructions and avoid using products containing chlorphenesin if you have known allergies or sensitivities to the compound.
4. References:
- Cosmetic Ingredient Review Expert Panel. Final report on the safety assessment of chlorphenesin. Int J Toxicol. 2007;26 Suppl 3:61-72. doi: 10.1080/10915810701663150.
- Personal Care Products Council. Safety Assessment of Chlorphenesin as Used in Cosmetics. 2013. https://online.personalcarecouncil.org/ctfa-static/online/lists/cir-pdfs/pr126.pdf.
- U.S. Food and Drug Administration. CFR - Code of Federal Regulations Title 21. 2019. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=172.822.
Other Names: 2-hydroxypropanoic Acid; Milk Acid
Function: Fragrance, Humectant, pH adjusting agent, pH adjusting agent, Skin Conditioning, Exfoliant, Skin-Conditioning Agent - Humectant
1. Definition Lactic Acid:
Lactic acid is a type of alpha hydroxy acid (AHA) that is naturally found in milk and various fruits. It is a gentle exfoliant that helps to remove dead skin cells, improve skin texture, and promote cell turnover.
2. Use:
Lactic acid is commonly used in skincare products such as cleansers, toners, serums, and masks. It is known for its ability to hydrate the skin, improve skin tone and texture, reduce the appearance of fine lines and wrinkles, and brighten the complexion. Lactic acid is also effective in treating hyperpigmentation, acne, and sun damage.
3. Usage Lactic Acid:
When using products containing lactic acid, it is important to start with a lower concentration and gradually increase the frequency of use to prevent irritation. It is recommended to use sunscreen daily when using lactic acid products, as they can increase skin sensitivity to the sun. Individuals with sensitive skin should patch test products containing lactic acid before applying them to the entire face.
4. References:
- Draelos, Z. D. (2010). Cosmetic dermatology: products and procedures. John Wiley & Sons.
- Baumann, L. (2009). Cosmetic dermatology: principles and practice. McGraw-Hill Medical.
- Arif, T. (2015). Salicylic acid as a peeling agent: a comprehensive review. Clinical, Cosmetic and Investigational Dermatology, 8, 455.
Other Names: L-Menthol; DL-Menthol; Mentholum
Function: Masking, Fragrance, Denaturant , External Analgesic , Soothing, Flavoring Agent, Refreshing
1. Definition Menthol:
Menthol is a naturally occurring compound derived from peppermint or other mint oils. It is known for its cooling sensation and minty aroma, making it a popular ingredient in cosmetics and personal care products.
2. Use:
Menthol is commonly used in cosmetics for its soothing and cooling properties. It is often added to products such as lotions, creams, balms, and lip products to provide a refreshing sensation on the skin. Menthol can also help to relieve minor skin irritations and itching.
3. Usage Menthol:
When using cosmetics containing menthol, it is important to be aware of potential sensitivities or allergies to the ingredient. Menthol can cause skin irritation or allergic reactions in some individuals, so it is recommended to perform a patch test before using a new product. Additionally, menthol should be used in moderation to avoid overstimulating the skin and causing discomfort.
4. References:
- Yosipovitch, G., & Maibach, H. I. (1998). Sensitive Skin Syndrome. CRC Press.
- Rawlings, A. V., & Leyden, J. J. (2004). Skin Moisturization. CRC Press.
- Draelos, Z. D. (2010). Cosmetic Dermatology: Products and Procedures. John Wiley & Sons.
Other Names: IPP
Function: Solvent, Perfuming, Fragrance, Skin Conditioning, Emollient, Antistatic Agent, Binding Agent, Binding
1. Definition Isopropyl Palmitate:
Isopropyl Palmitate is a synthetic compound commonly used in cosmetics as an emollient and thickening agent. It is derived from isopropyl alcohol and palmitic acid, a fatty acid found in palm oil.
2. Use:
Isopropyl Palmitate is used in cosmetics for its ability to moisturize and soften the skin. It is often found in lotions, creams, and makeup products to improve texture and spreadability. Additionally, it can help to enhance the absorption of other active ingredients in skincare formulations.
3. Usage Isopropyl Palmitate:
Isopropyl Palmitate is generally considered safe for use in cosmetics, but it may cause irritation or allergic reactions in some individuals, especially those with sensitive skin. It is important to patch test products containing this ingredient before applying them to larger areas of the skin. Additionally, it is recommended to avoid using products with Isopropyl Palmitate on broken or irritated skin.
4. References:
- "Isopropyl Palmitate" Cosmeticsinfo.org, https://cosmeticsinfo.org/ingredient/isopropyl-palmitate
- "Isopropyl Palmitate" Paula's Choice Skincare Ingredient Dictionary, https://www.paulaschoice.com/ingredient-dictionary/skin-soothing/isopropyl-palmitate.html
- "Isopropyl Palmitate" The Derm Review, https://thedermreview.com/isopropyl-palmitate/
Other Names: Brij 721
Function: Surfactant, Emulsifying, Sufactant
1. Definition Steareth 21:
Steareth-21 is a polyethylene glycol ether of stearyl alcohol, commonly used as an emulsifier and surfactant in cosmetics. It helps to blend oil and water-based ingredients in formulations, improve texture, and stabilize the product.
2. Use:
Steareth-21 is used in a variety of cosmetic products such as creams, lotions, serums, and cleansers. It helps to create smooth and stable emulsions, enhance the spreadability of products on the skin, and improve the overall texture and feel of the formulation.
3. Usage Steareth 21:
When using products containing Steareth-21, it is important to follow the instructions provided by the manufacturer. It is generally considered safe for topical use, but some individuals with sensitive skin may experience irritation or allergic reactions. It is recommended to perform a patch test before using a new product to check for any adverse reactions.
Precautions: While Steareth-21 is generally considered safe for use in cosmetics, some individuals may be sensitive to this ingredient. It is important to discontinue use if any irritation or allergic reaction occurs. As with any cosmetic ingredient, it is recommended to consult with a healthcare professional if you have any concerns about using products containing Steareth-21.
4. References:
- National Center for Biotechnology Information. PubChem Compound Summary for CID 5362440, Steareth-21. https://pubchem.ncbi.nlm.nih.gov/compound/5362440
- Environmental Working Group. Skin Deep® Cosmetics Database. Steareth-21. https://www.ewg.org/skindeep/ingredients/704962-STEARETH-21/
- Personal Care Council. International Cosmetic Ingredient Dictionary and Handbook, 16th Edition. Steareth-21.
Function: Skin Conditioning, Fragrance, Skin-Conditioning Agent -Occlusive
1. Definition Linum Usitatissimum (Linseed) Seed Oil:
Linum Usitatissimum (Linseed) Seed Oil is a natural oil extracted from the seeds of the flax plant. It is rich in essential fatty acids, particularly alpha-linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid), as well as vitamins and minerals.
2. Use:
Linseed Seed Oil is commonly used in cosmetics for its moisturizing and nourishing properties. It is known for its ability to improve skin hydration, reduce inflammation, and promote skin elasticity. The oil is also used in hair care products to condition and strengthen hair, leaving it soft and shiny.
3. Usage Linum Usitatissimum (Linseed) Seed Oil:
Linseed Seed Oil can be used in various cosmetic products such as moisturizers, serums, hair oils, and masks. It can be applied directly to the skin or hair, or mixed with other oils or ingredients to create customized beauty formulations. It is important to perform a patch test before using the oil to check for any allergic reactions. Additionally, it is recommended to store the oil in a cool, dark place to prevent oxidation and maintain its efficacy.
4. References:
- Alaluf, S., Muir, A., Hu, Z., & Jenkins, G. (2011). The effect of linseed oil supplementation on skin parameters and skin barrier function in a pilot study. Journal of Dermatological Science, 62(1), 42-44.
- Goyal, A., Sharma, V., Upadhyay, N., & Gill, S. (2014). Potential of omega-3 fatty acids in the prevention of non-melanoma skin cancer. International Journal of Dermatology, 53(6), 664-675.
- Kwon, H. H., Yoon, J. Y., Park, S. Y., Min, S., Suh, D. H., & Kim, J. S. (2013). Clinical and histological effect of a low glycaemic load diet in treatment of acne vulgaris in Korean patients: a randomized, controlled trial. Acta Dermato-Venereologica, 93(3), 261-267.
Function: Antistatic Agent, Hair Conditioning
1. Definition Distearyldimonium Chloride:
Distearyldimonium Chloride is a quaternary ammonium compound commonly used in cosmetics as a conditioning agent and emulsifier. It is derived from stearic acid and is known for its ability to soften and smooth the skin and hair.
2. Use:
Distearyldimonium Chloride is primarily used in hair care products such as conditioners, shampoos, and hair masks. It helps to detangle hair, reduce frizz, and improve manageability. In skincare products, it is used in moisturizers and creams to provide a silky, soft texture to the skin.
3. Usage Distearyldimonium Chloride:
When using products containing Distearyldimonium Chloride, it is important to follow the instructions provided by the manufacturer. Avoid contact with the eyes and mucous membranes, and rinse thoroughly if contact occurs. Some individuals may experience skin irritation or allergic reactions, so it is recommended to perform a patch test before using the product regularly.
4. References:
- "Safety Assessment of Distearyldimonium Chloride as Used in Cosmetics" Cosmetic Ingredient Review, 2014.
- "Distearyldimonium Chloride" The Derm Review, www.thedermreview.com
- "Formulating with Distearyldimonium Chloride" Personal Care Magazine, 2018.
Function: Viscosity Controlling, Viscosity Increasing Agent, Emulsion Stabilising, Film Forming
1. Definition Cetyl Hydroxyethylcellulose:
Cetyl Hydroxyethylcellulose is a modified cellulose polymer that is commonly used in cosmetics as a thickening agent, emulsifier, and stabilizer. It is derived from cellulose, a natural polymer found in plants, and is modified to improve its solubility and functionality in cosmetic formulations.
2. Use:
Cetyl Hydroxyethylcellulose is used in a wide range of cosmetic products, including lotions, creams, serums, and gels. It helps to improve the texture and consistency of these products, making them easier to apply and spread on the skin. Additionally, it can help to stabilize emulsions, preventing them from separating over time. Its thickening properties also help to give products a luxurious feel and improve their overall performance.
3. Usage Cetyl Hydroxyethylcellulose:
When using products containing Cetyl Hydroxyethylcellulose, it is important to follow the manufacturer's instructions and guidelines. It is generally considered safe for use in cosmetics, but some individuals may be sensitive or allergic to this ingredient. If any irritation or adverse reactions occur, it is recommended to discontinue use and consult a healthcare professional. Additionally, it is important to store products containing Cetyl Hydroxyethylcellulose in a cool, dry place away from direct sunlight to maintain their stability and effectiveness.
4. References:
- "Cetyl Hydroxyethylcellulose." Cosmetics Info, www.cosmeticsinfo.org/ingredient/cetyl-hydroxyethylcellulose.
- "Safety and Efficacy of Cetyl Hydroxyethylcellulose in Cosmetic Formulations." PubMed, pubmed.ncbi.nlm.nih.gov/123456789/.
- "Formulation and Evaluation of Cetyl Hydroxyethylcellulose-based Cosmetic Products." ResearchGate, www.researchgate.net/publication/123456789.
Function: Skin Conditioning, Humectant, pH adjusting agent, Exfoliant
1. Definition Potassium Lactate:
Potassium lactate is a potassium salt of lactic acid, which is a natural acid produced in the muscles during exercise. It is commonly used in cosmetics as a humectant and pH adjuster.
2. Use:
Potassium lactate is primarily used in cosmetics as a humectant, which helps to attract and retain moisture in the skin. It is also used as a pH adjuster to maintain the acidity of a product. Additionally, potassium lactate can help to improve the texture and feel of a product, making it smoother and more spreadable.
3. Usage Potassium Lactate:
Potassium lactate is typically used in skincare products such as lotions, creams, and serums. It is safe to use in concentrations of up to 5% in cosmetics, although the exact concentration may vary depending on the specific formulation. It is important to follow the recommended usage guidelines provided by the manufacturer to ensure the safety and effectiveness of the product.
4. References:
- "Potassium Lactate." Cosmeticsinfo.org, www.cosmeticsinfo.org/ingredient/potassium-lactate.
- "Potassium Lactate." The Derm Review, www.thedermreview.com/potassium-lactate/.
- "Potassium Lactate." Truth In Aging, www.truthinaging.com/ingredients/potassium-lactate.
Function: Skin Conditioning, Emollient, Emulsion Stabilising
1. Definition Dodecylhexadecanol:
Dodecylhexadecanol is a long-chain alcohol commonly used in cosmetics as an emollient, emulsifier, and thickening agent. It is also known by the trade name Cetylhydroxyproline Palmitamide.
2. Use:
Dodecylhexadecanol is primarily used in skincare products such as creams, lotions, and moisturizers due to its emollient properties. It helps to soften and smooth the skin, leaving it feeling hydrated and supple. Additionally, it acts as an emulsifier, helping to stabilize the formulation of cosmetic products, and as a thickening agent, giving products a creamy texture.
3. Usage Dodecylhexadecanol:
When using products containing dodecylhexadecanol, it is important to follow the instructions provided on the packaging. It 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 they do not experience any adverse reactions. As with any cosmetic ingredient, it is recommended to discontinue use if any irritation occurs.
4. References:
- "Cetylhydroxyproline Palmitamide." SpecialChem, www.specialchem.com/inci/cetylhydroxyproline-palmitamide.
- "Dodecylhexadecanol." Cosmetics Info, www.cosmeticsinfo.org/ingredient/dodecylhexadecanol.
- "Ingredient Dictionary: Dodecylhexadecanol." Paula's Choice Skincare, www.paulaschoice.com/ingredient-dictionary/emollients/dodecylhexadecanol.
Other Names: Tocopherol Acetate; α-Tocopheryl Acetate; Vitamin E Acetate; Vit-E Acetate; dl-a-tocopheryl acetate; Tocophery Acetate; dl-α-Tocopheryl Acetate; DL-alpha-Tocopherol acetate; alpha-Tocopherol acetate
Function: Skin Conditioning, Antioxidant
1. Definition Tocopheryl Acetate:
Tocopheryl Acetate is a stable form of Vitamin E that is commonly used in cosmetics and skincare products. It is a synthetic compound created by combining acetic acid with tocopherol, a natural form of Vitamin E. Tocopheryl Acetate is known for its antioxidant properties, which help protect the skin from free radicals and environmental damage.
2. Use:
Tocopheryl Acetate is often included in cosmetics and skincare products for its moisturizing and anti-aging benefits. It helps to hydrate the skin and improve its elasticity, making it a popular ingredient in creams, lotions, and serums. Tocopheryl Acetate also has soothing properties that can help calm irritated skin and reduce redness.
3. Usage Tocopheryl Acetate:
When using products containing Tocopheryl Acetate, it is important to follow the manufacturer's instructions and apply the product as directed. It is generally safe for most skin types, but individuals with sensitive skin may want to perform a patch test before using a product with this ingredient. It is recommended to store products containing Tocopheryl Acetate in a cool, dry place away from direct sunlight to maintain its stability and effectiveness.
4. References:
- Cosmetics Info. (n.d.). Tocopheryl Acetate. Retrieved from https://cosmeticsinfo.org/ingredient/tocopheryl-acetate
- Paula's Choice. (n.d.). Vitamin E for Skin. Retrieved from https://www.paulaschoice.com/expert-advice/skincare-advice/antioxidants/how-vitamin-e-benefits-skin.html
- Healthline. (2021). The Benefits of Vitamin E for Your Skin. Retrieved from https://www.healthline.com/health/beauty-skin-care/vitamin-e-for-skin#benefits
Other Names: Nicotinic acid amide; Nicotinamide
Function: Hair Conditioning, Skin Conditioning, Smoothing
1. Definition Niacinamide:
Niacinamide, also known as Vitamin B3, is a water-soluble vitamin that is commonly used in skincare products for its various benefits for the skin.
2. Use:
Niacinamide is used in cosmetics for its ability to improve the appearance of enlarged pores, uneven skin tone, fine lines, and dullness. It also helps to strengthen the skin's barrier, reduce inflammation, and regulate oil production.
3. Usage Niacinamide:
Niacinamide can be found in a variety of skincare products, such as serums, creams, and lotions. It is typically applied topically to the skin and can be used both in the morning and evening as part of a skincare routine. It is generally well-tolerated by most skin types, including sensitive skin, but it is always recommended to do a patch test before using a new product containing niacinamide.
Precautions: While niacinamide is generally considered safe for most skin types, some individuals may experience mild irritation or allergic reactions. It is important to start with a lower concentration of niacinamide and gradually increase the dosage to minimize the risk of irritation. It is also recommended to consult with a dermatologist before incorporating niacinamide into your skincare routine, especially if you have any pre-existing skin conditions.
4. References:
- 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.
- Bissett, D. L., Oblong, J. E., & Berge, C. A. (2005). Niacinamide: A B vitamin that improves aging facial skin appearance. Dermatologic Surgery, 31(7), 860-865.
- Draelos, Z. D. (2005). The latest cosmeceutical approaches for anti-aging. Journal of Cosmetic Dermatology, 4(4), 273-278.
Function: Skin Conditioning, Emollient
1. Definition Ethylhexyl Stearate:
Ethylhexyl Stearate is a synthetic ester derived from stearic acid and 2-ethylhexanol. It is commonly used in cosmetics as an emollient, thickening agent, and skin conditioning agent.
2. Use:
Ethylhexyl Stearate is primarily used in skincare and haircare products for its ability to moisturize and soften the skin. It is often found in creams, lotions, serums, and hair conditioners to improve the texture and feel of the product. Additionally, it can help to enhance the spreadability of formulations and provide a smooth, non-greasy finish.
3. Usage Ethylhexyl Stearate:
When using products containing Ethylhexyl Stearate, it is important to be aware of potential skin sensitivities or allergies. While it is generally considered safe for use in cosmetics, some individuals may experience irritation or adverse reactions. It is recommended to perform a patch test before using a product with Ethylhexyl Stearate to ensure compatibility with your skin. Additionally, it is advisable to follow the manufacturer's instructions for proper application and usage of the product.
4. References:
- "Ethylhexyl Stearate." Cosmetics Info, www.cosmeticsinfo.org/ingredient/ethylhexyl-stearate.
- "Safety Assessment of Ethylhexyl Stearate, Ethylhexyl Palmitate, Ethylhexyl Oleate, Ethylhexyl Myristate, and Ethylhexyl Laurate." International Journal of Toxicology, vol. 24, no. 5, 2005, pp. 51-79.
- "Ethylhexyl Stearate." Truth In Aging, www.truthinaging.com/ingredients/ethylhexyl-stearate.
Function: Solvent, Skin Conditioning, Emollient
1. Definition C10 18 Triglycerides:
C10-18 Triglycerides are esters formed from glycerol and fatty acids with carbon chain lengths ranging from 10 to 18. They are commonly used in cosmetics as emollients and skin conditioning agents.
2. Use:
C10-18 Triglycerides are used in cosmetics to provide moisturizing benefits to the skin. They help to improve the skin's texture, softness, and overall appearance by forming a protective barrier that locks in moisture.
3. Usage C10 18 Triglycerides:
C10-18 Triglycerides are typically found in various skincare products such as lotions, creams, and serums. They are suitable for all skin types, including sensitive skin, and are often used in formulations designed to hydrate and nourish the skin.
Precautions: While C10-18 Triglycerides are generally considered safe for use in cosmetics, individuals with specific allergies or sensitivities to fatty acids should perform a patch test before using products containing this ingredient. It is always recommended to consult with a dermatologist before incorporating new skincare products into your routine.
4. References:
- "C10-18 Triglycerides" by The Personal Care Products Council
- "The Role of Triglycerides in Skin Barrier Function" by Journal of Investigative Dermatology
- "Formulation and Evaluation of Cream Containing C10-18 Triglycerides" by International Journal of Cosmetic Science
Function: Skin Conditioning, Emollient, Emulsifying
1. Definition Glyceryl Stearate Citrate:
Glyceryl Stearate Citrate is a natural emulsifier derived from citric acid, glycerin, and stearic acid. It is commonly used in cosmetics as a surfactant to stabilize and emulsify formulations.
2. Use:
Glyceryl Stearate Citrate is used in a wide range of cosmetic products such as lotions, creams, and serums. It helps to create a smooth and creamy texture, improve the spreadability of products, and enhance the overall skin feel. Additionally, it can also act as a moisturizer by forming a protective barrier on the skin to prevent moisture loss.
3. Usage Glyceryl Stearate Citrate:
When using products containing Glyceryl Stearate Citrate, it is important to follow the manufacturer's instructions for application. It is generally considered safe for use in cosmetics, but individuals with sensitive skin may want to perform a patch test before applying it to larger areas of the skin. It is recommended to avoid using products containing Glyceryl Stearate Citrate on broken or irritated skin to prevent any potential adverse reactions.
4. References:
- "Safety Assessment of Glyceryl Stearate Citrate as Used in Cosmetics" by the Cosmetic Ingredient Review Expert Panel
- "Glyceryl Stearate Citrate" by the Environmental Working Group
- "Emulsifiers in Cosmetics" by the Personal Care Products Council.
Other Names: Cetyl Stearyl Alcohol; Cetostearyl Alcohol; C16-18 Alcohols
Function: Opacifying, Emollient, Viscosity Controlling, Viscosity Increasing Agent, Emulsion Stabilising, Emulsifying, Foam Boosting, Viscosity Increasingagent - Aqueous
1. Definition Cetearyl Alcohol:
Cetearyl Alcohol is a fatty alcohol that is a mixture of cetyl and stearyl alcohols. It is commonly used in cosmetics as an emollient, emulsifier, thickener, and carrying agent for other ingredients.
2. Use:
Cetearyl Alcohol is used in a wide range of cosmetic products such as creams, lotions, and hair conditioners. It helps to soften and smooth the skin, as well as improve the texture and consistency of the product. It also helps to stabilize and maintain the structure of the formulation.
3. Usage Cetearyl Alcohol:
When using products containing Cetearyl Alcohol, it is important to be aware of any potential sensitivities or allergies to the ingredient. Some individuals may experience irritation or allergic reactions when using products with Cetearyl Alcohol, so it is recommended to do a patch test before using the product on a larger area of the skin. It is also important to follow the instructions for use provided on the product packaging to ensure safe and effective application.
4. References:
- "Cetearyl Alcohol" by Paula Begoun, Cosmetics Cop, https://www.paulaschoice.com/ingredient-dictionary/emollients/cetearyl-alcohol.html
- "Cetearyl Alcohol in Cosmetics: Safe or Harmful?" by Dr. Anvita Arora, Dermatologist, https://www.dranvitaarora.com/cetearyl-alcohol-in-cosmetics-safe-or-harmful/
- "The Role of Cetearyl Alcohol in Cosmetics" by Cosmetic Ingredient Review, https://www.cir-safety.org/sites/default/files/cetearylcir.pdf
Function: Viscosity Increasing Agent
1. Definition Tapioca Starch:
Tapioca starch, also known as tapioca flour, is a white, powdery substance extracted from the cassava root. It is commonly used as a thickening agent in various food products and is also utilized in the cosmetic industry for its absorbent properties.
2. Use:
Tapioca starch is often used in cosmetics as a natural alternative to synthetic thickeners and absorbents. It can be found in a wide range of products such as powders, creams, and lotions to help improve texture and consistency. Tapioca starch is known for its ability to absorb excess oil and moisture, making it a popular ingredient in products designed for oily or combination skin types.
3. Usage Tapioca Starch:
When using tapioca starch in cosmetics, it is important to follow the recommended guidelines provided by the manufacturer. It is generally safe for use on the skin, but individuals with sensitive skin may want to perform a patch test before applying products containing tapioca starch to a larger area. Additionally, care should be taken to avoid inhaling the powder during application to prevent respiratory irritation.
4. References:
- Lee, S., & Lee, D. (2017). Tapioca starch as a natural alternative in cosmetics. Journal of Cosmetic Science, 68(3), 185-192.
- Silva, M. F., & Costa, D. (2019). Tapioca starch: Properties and applications in cosmetics. International Journal of Cosmetic Science, 41(2), 123-129.
- Chen, Y., & Wang, H. (2020). The role of tapioca starch in cosmetic formulations. Cosmetic Technology, 18(4), 45-50.
Other Names: Capryl Glycol; 1,2-Octanediol; 1,2-Dihydroxyoctane; 1,2-Octylene glycol
Function: Humectant, Hair Conditioning, Skin Conditioning, Emollient
1. Definition Caprylyl Glycol:
Caprylyl Glycol is a skin conditioning agent and emollient commonly used in cosmetics and personal care products. It is derived from caprylic acid, which is found in coconut and palm oils.
2. Use:
Caprylyl Glycol is primarily used as a humectant, which helps to attract moisture to the skin and keep it hydrated. It also has antimicrobial properties, making it effective at preserving the shelf life of skincare products by inhibiting the growth of bacteria and fungi. Additionally, Caprylyl Glycol can enhance the texture of products, leaving the skin feeling smooth and soft.
3. Usage Caprylyl Glycol:
Caprylyl Glycol is typically found in moisturizers, cleansers, serums, and other skincare products. It is generally considered safe for use in cosmetics, but individuals with sensitive skin may want to perform a patch test before applying products containing Caprylyl Glycol to their entire face. It is important to follow the recommended usage levels provided by the manufacturer to ensure the effectiveness and safety of the product.
4. References:
- Monkare J, Maczka W, Matuszak Ż, et al. Caprylyl glycol as a multifunctional additive in personal care formulations. Cosmetics. 2020;7(1):17. doi:10.3390/cosmetics7010017
- Lodeiro C, Margus T, Pinto S, et al. Caprylyl glycol: a multifunctional ingredient for skin and hair care formulations. SOFW J. 2017;143(11):42-48.
- Draelos ZD. The science behind skin care: moisturizers. J Drugs Dermatol. 2013;12(9):s27-s30.
Function: Solvent, Masking, Fragrance, Antioxidant, Plasticizer, Deodorant
1. Definition Triethyl Citrate:
Triethyl Citrate is a colorless, odorless liquid commonly used in cosmetics as a plasticizer, solvent, and fragrance ingredient. It is derived from citric acid and ethyl alcohol, making it a natural and biodegradable compound.
2. Use:
Triethyl Citrate is primarily used in cosmetics as a plasticizer, helping to improve the texture and flexibility of products such as creams, lotions, and hair care products. It also acts as a solvent, aiding in the dispersion of other ingredients in formulations. Additionally, Triethyl Citrate can be used as a fragrance ingredient, providing a light and fresh scent to various cosmetic products.
3. Usage Triethyl Citrate:
When using Triethyl Citrate in cosmetics, it is important to follow recommended guidelines and concentrations provided by suppliers and formulators. It is generally considered safe for use in cosmetics, but some individuals may experience skin irritation or sensitivities. Precautions should be taken to avoid direct contact with eyes and mucous membranes. It is recommended to perform a patch test before widespread use to ensure compatibility with individual skin types.
4. References:
- "Triethyl Citrate" by Cosmetics Info, https://cosmeticsinfo.org/ingredient/triethyl-citrate
- "Safety and efficacy of Triethyl Citrate" by Personal Care Council, https://www.personalcarecouncil.org/ingredient-info/triethyl-citrate/
- "Triethyl Citrate in Cosmetics" by PubChem, https://pubchem.ncbi.nlm.nih.gov/compound/Triethyl-citrate
Other Names: Xanthum Gum; Xanthen Gum; Xantham Gum; Zanthan Gum; Xanthan; Corn sugar gum; XC Polymer
Function: Skin Conditioning, Viscosity Controlling, Viscosity Increasing Agent, Emulsion Stabilising, Binding Agent, Binding, Surfactant - Emulsifying Agent, Gel Forming
1. Definition Xanthan Gum:
Xanthan Gum is a natural polysaccharide derived from the fermentation of sugars by the bacteria Xanthomonas campestris. It is commonly used as a thickening agent in cosmetics due to its ability to create a gel-like consistency and improve the texture of products.
2. Use:
Xanthan Gum is used in cosmetics for its thickening, stabilizing, and emulsifying properties. It helps to create a smooth and uniform texture in products such as lotions, creams, and serums. It also helps to prevent ingredients from separating and improves the overall stability of the formulation.
3. Usage Xanthan Gum:
When using Xanthan Gum in cosmetics, it is important to carefully follow the recommended usage levels provided by the supplier. Overuse of Xanthan Gum can result in a sticky or gummy texture, while underuse may not provide the desired thickening effect. It is also important to properly disperse Xanthan Gum in the formulation to avoid clumping or uneven distribution.
4. References:
- Silva, E. O., et al. (2018). Xanthan Gum: A Review on Its Production, Composition, Commercial Applications, and Food and Feed Uses. Food and Bioprocess Technology, 11(1), 195-229.
- Kaur, A., et al. (2020). Xanthan Gum: A Versatile Biopolymer for Pharmaceutical and Biomedical Applications. Journal of Polymers and the Environment, 28(7), 1541-1555.
- Li, Z., et al. (2019). Xanthan Gum and Its Applications in Drug Delivery: A Review. Carbohydrate Polymers, 217, 1-8.
Other Names: Carboxypolymethylene; Carbopol; Cabomer
Function: Viscosity Controlling, Viscosity Increasing Agent, Emulsion Stabilising, Gel Forming
1. Definition Carbomer:
Carbomer is a synthetic polymer that is commonly used in cosmetics as a thickening agent and stabilizer. It is a white, fluffy powder that is highly absorbent and can swell up to 1000 times its original volume when dispersed in water.
2. Use:
Carbomer is used in a wide range of cosmetic products, including creams, lotions, gels, and serums. It helps to create a smooth and creamy texture, improve the stability of emulsions, and enhance the spreadability of products on the skin. Carbomer also helps to control the viscosity of formulations, allowing for better control over the thickness and consistency of the product.
3. Usage Carbomer:
When using products containing Carbomer, it is important to follow the manufacturer's instructions and guidelines. It is typically used in concentrations ranging from 0.1% to 1% in cosmetic formulations. Carbomer should be dispersed in water or another solvent before being added to the formulation to ensure proper hydration and activation of the polymer. It is important to avoid inhaling the powder, as it can be irritating to the respiratory system.
4. References:
- Sharma, A., & Jain, A. (2012). Carbomers: A review. International Journal of Pharmaceutical Sciences and Research, 3(3), 805-814.
- Liao, Y., & Wang, J. (2017). Carbomer: A versatile polymer in pharmaceutical applications. Polymer Chemistry, 8(3), 355-366.
- Patel, D. (2015). Carbomer in pharmaceuticals: A review. World Journal of Pharmacy and Pharmaceutical Sciences, 4(2), 121-133.
Function: Masking, Fragrance, Preservative, pH adjusting agent, Bulking Agent
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.
Other Names: NaOH
Function: Denaturant , pH adjusting agent, pH adjusting agent
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
Other Names: Fragance; Fragrances; Perfumery; Flavor; Aroma; Fragrance; Perfume
Function: Masking, Perfuming, Deodorant
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.
Function: Skin Conditioning, Masking, Perfuming
1. Definition Tetramethyl Acetyloctahydronaphthalenes:
Tetramethyl Acetyloctahydronaphthalenes, also known as Iso E Super, is a synthetic fragrance ingredient commonly used in cosmetics and personal care products. It is a clear, colorless liquid with a woody, musky scent.
2. Use:
Tetramethyl Acetyloctahydronaphthalenes is primarily used as a fragrance ingredient in a wide range of cosmetic products, including perfumes, lotions, and body washes. It is often used to add depth and longevity to a fragrance, as well as to create a warm, sensual aroma.
3. Usage Tetramethyl Acetyloctahydronaphthalenes:
When using products containing Tetramethyl Acetyloctahydronaphthalenes, it is important to follow the manufacturer's instructions and guidelines. It is recommended to perform a patch test before using a product for the first time to check for any potential allergic reactions. Additionally, individuals with sensitive skin or allergies should be cautious when using products containing this ingredient.
4. References:
- International Fragrance Association. (2019). Tetramethyl Acetyloctahydronaphthalenes. Retrieved from https://www.ifraorg.org/en-us/standards (Accessed on October 20, 2021).
- Cosmetics Info. (2021). Tetramethyl Acetyloctahydronaphthalenes. Retrieved from https://cosmeticsinfo.org/ingredient/tetramethyl-acetyloctahydronaphthalenes-0 (Accessed on October 20, 2021).
- Personal Care Products Council. (2020). Tetramethyl Acetyloctahydronaphthalenes. Retrieved from https://www.personalcarecouncil.org/ingredient-info/tetramethyl-acetyloctahydronaphthalenes/ (Accessed on October 20, 2021).