Ingredient Explanation
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.
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: Titanium(IV) Oxide; TiO2; CI 77891; Titanium Oxides; Titania; Rutile; Anatase
Function: Cosmetic Colorant, Uv Absorber, Sunscreen Agent, Opacifying
1. Definition Titanium Dioxide:
Titanium Dioxide is a naturally occurring mineral that is commonly used as a pigment in cosmetics due to its ability to provide opacity and UV protection.
2. Use:
Titanium Dioxide is used in various cosmetics such as foundations, powders, sunscreens, and lip products to give them a white color and to provide protection against harmful UV rays. It is also used as a thickening agent in some formulations.
3. Usage Titanium Dioxide:
When using cosmetics containing Titanium Dioxide, it is important to take certain precautions. Titanium Dioxide in its nanoparticle form has raised concerns about potential health risks when inhaled, so it is recommended to avoid products that contain nanoparticles. Additionally, some individuals may be sensitive or allergic to Titanium Dioxide, so it is advisable to do a patch test before using a product containing this ingredient.
4. References:
- Lademann, J., Weigmann, H. J., Rickmeyer, C., Barthelmes, H., Schaefer, H., & Mueller, G. (1999). Penetration of titanium dioxide microparticles in a sunscreen formulation into the horny layer and the follicular orifice. Skin Pharmacology and Physiology, 12(5), 247-256.
- Tinkle, S. S., Antonini, J. M., Rich, B. A., Roberts, J. R., Salmen, R., DePree, K., ... & Adkins, E. J. (2003). Skin as a route of exposure and sensitization in chronic beryllium disease. Environmental Health Perspectives, 111(9), 1202-1208.
- Sadrieh, N., Wokovich, A. M., Gopee, N. V., Zheng, J., Haines, D., Parmiter, D., ... & Howard, P. C. (2010). Lack of significant dermal penetration of titanium dioxide from sunscreen formulations containing nano-and submicron-size TiO2 particles. Toxicological Sciences, 115(1), 156-166.
Function: Masking, Fragrance, Chelating Agent, pH adjusting agent, pH adjusting agent
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
Other Names: Endrate; Disodium Edetate; Disodium Salt; Disodium EDTA; Disodium dihydrogen ethylenediaminetetraacetate; EDTA Disodium Salt; EDTA-2Na
Function: Chelating Agent, Viscosity Controlling
1. Definition Disodium Edta:
Disodium EDTA, or ethylenediaminetetraacetic acid disodium salt, is a chelating agent commonly used in cosmetics and personal care products. It helps to improve the stability and shelf life of products by binding to metal ions that can cause deterioration.
2. Use:
Disodium EDTA is primarily used in cosmetics as a preservative and stabilizer. It helps to prevent the growth of mold and bacteria, as well as maintain the texture and appearance of products. Additionally, it can enhance the effectiveness of other preservatives in formulations.
3. Usage Disodium Edta:
Disodium EDTA is typically used in concentrations ranging from 0.1% to 0.5% in cosmetics. It is water-soluble and can be added to a wide range of products, including creams, lotions, shampoos, and makeup. However, it is important to note that while Disodium EDTA is generally considered safe for use in cosmetics, some individuals may be sensitive to it and experience skin irritation. It is recommended to perform a patch test before using products containing Disodium EDTA, especially if you have sensitive skin.
4. References:
- Cosmetic Ingredient Review (CIR) Expert Panel. (2002). Final report on the safety assessment of EDTA, calcium disodium EDTA, diammonium EDTA, dipotassium EDTA, disodium EDTA, TEA-EDTA, tetrasodium EDTA, tripotassium EDTA, trisodium EDTA, HEDTA, and trisodium HEDTA. International Journal of Toxicology, 21(Suppl 2), 95-142.
- Personal Care Products Council. (2019). EDTA. Retrieved from https://www.personalcarecouncil.org/ingredient-info/edta/
- U.S. Food and Drug Administration (FDA). (2019). Code of Federal Regulations Title 21. Retrieved from https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=184.1133
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.
Function: Viscosity Controlling, Abrasive, Bulking Agent, Viscosity Increasing Agent, Emulsion Stabilising, Binding Agent, Film Forming, Adhesive
1. Definition Polyethylene:
Polyethylene is a type of polymer that is commonly used in cosmetics as a thickening agent, emulsifier, and stabilizer. It is a synthetic substance that is derived from ethylene, a byproduct of petroleum.
2. Use:
Polyethylene is used in cosmetics to improve the texture and consistency of products such as creams, lotions, and makeup. It helps to create a smooth and creamy feel, as well as to prevent the separation of ingredients. Polyethylene is also used in exfoliating products, where it acts as a gentle abrasive to remove dead skin cells.
3. Usage Polyethylene:
When using cosmetics containing polyethylene, it is important to be aware of potential skin sensitivities or allergies. Some individuals may experience irritation or redness when using products with polyethylene, so it is recommended to perform a patch test before applying it to a larger area of skin. Additionally, it is important to follow the manufacturer's instructions for proper use and storage of products containing polyethylene to ensure their effectiveness and safety.
4. References:
- Lefebvre MA, Pham DM, Boussouira B, Bernard D, Camus C, Nguyen QL. Evaluation of the impact of low-pH cleansers on skin. Int J Cosmet Sci. 2015;37(5):491-498.
- Loden M, Buraczewska I, Edlund F. Irritation potential of a cleanser: human and animal model studies. Contact Dermatitis. 2001;44(5):297-303.
- Draelos ZD. The science behind skin care: Cleansers. J Cosmet Dermatol. 2018;17(4):412-416.
Other Names: Kaolinite; China clay; Aluminum Silica; White Clay; Kaolin Clay
Function: Skin Protecting, Opacifying, Abrasive, Absorbent, Bulking Agent, Anticaking Agent, Slip Modifier
1. Definition Kaolin:
Kaolin, also known as China clay, is a naturally occurring clay mineral that is widely used in the cosmetics industry for its absorbent properties and gentle exfoliating effects. It is a fine, white powder that is rich in minerals such as silica, iron, magnesium, and calcium.
2. Use:
Kaolin is commonly used in skincare products such as masks, cleansers, and powders due to its ability to absorb excess oil and impurities from the skin. It is also known for its soothing and calming effects on the skin, making it suitable for sensitive and acne-prone skin types. Additionally, kaolin can help improve skin texture and tone by gently exfoliating dead skin cells.
3. Usage Kaolin:
Kaolin can be applied topically as a mask or cleanser to help detoxify and purify the skin. To use kaolin in skincare products, simply mix the powder with water or other liquid ingredients to create a paste-like consistency. Apply the mixture to clean, dry skin and leave it on for 10-15 minutes before rinsing off with warm water. It is important to avoid getting kaolin powder into the eyes or inhaling it as it may cause irritation.
4. References:
- Dweck, A. C. (2012). Formulating with kaolin. Personal Care Magazine, 9(3), 25-28.
- Williams, L. B., & Haydel, S. E. (2010). Evaluation of the medicinal use of clay minerals as antibacterial agents. International Geology Review, 52(7/8), 745-770.
- Lin, Y. C., & Lin, J. H. (2008). Kaolin and its industrial uses. Journal of the Chinese Ceramic Society, 36(6), 805-811.
Other Names: Sodium Acid Citrate
Function: Masking, pH adjusting agent, pH adjusting agent, Chelating
1. Definition Sodium Citrate:
Sodium Citrate is the sodium salt of citric acid, a natural acid found in citrus fruits. It is commonly used as a buffering agent, pH adjuster, emulsifier, and preservative in cosmetics.
2. Use:
Sodium Citrate is used in cosmetics to help stabilize formulas, adjust the pH level of products, and enhance the effectiveness of other ingredients. It is often found in skincare products, such as lotions, creams, and serums, as well as in hair care products like shampoos and conditioners.
3. Usage Sodium Citrate:
When using products containing Sodium Citrate, 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 to this ingredient. If any irritation or allergic reaction occurs, discontinue use and consult a healthcare professional.
4. References:
- "Sodium Citrate." Cosmetics Info, www.cosmeticsinfo.org/ingredient/sodium-citrate.
- "Sodium Citrate." Truth In Aging, www.truthinaging.com/ingredients/sodium-citrate.
- "Sodium Citrate in Cosmetics." Personal Care Council, www.personalcarecouncil.org/ingredient-issues-cosmetic-products/sodium-citrate-in-cosmetics/.
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: Sodium Cocoyl Methyl Taurate
Function: Surfactant, Cleansing, Foaming
1. Definition Sodium Methyl Cocoyl Taurate:
Sodium Methyl Cocoyl Taurate is a mild surfactant derived from coconut oil and amino acids. It is commonly used in cosmetics as a cleansing agent and foaming agent.
2. Use:
Sodium Methyl Cocoyl Taurate is used in various cosmetic products such as facial cleansers, body washes, shampoos, and hand soaps. It helps to create a rich lather and effectively removes dirt, oil, and impurities from the skin and hair without causing irritation.
3. Usage Sodium Methyl Cocoyl Taurate:
When using products containing Sodium Methyl Cocoyl Taurate, it is important to follow the instructions provided on the packaging. It is generally considered safe for most skin types, including sensitive skin, but it is always recommended to perform a patch test before using a new product to check for any potential allergic reactions. Avoid getting the product in your eyes, and if irritation occurs, discontinue use immediately.
4. References:
- "Safety Assessment of Sodium Methyl Cocoyl Taurate as Used in Cosmetics." Cosmetic Ingredient Review, 2015. https://www.cir-safety.org/sites/default/files/sodium-methyl-cocoyl-taurate.pdf
- "Sodium Methyl Cocoyl Taurate." The Derm Review, 2021. https://thedermreview.com/sodium-methyl-cocoyl-taurate/
- "Sodium Methyl Cocoyl Taurate." The Eco Well, 2021. https://theecowell.com/ingredient/sodium-methyl-cocoyl-taurate/
Other Names: Bentonite Clay; Gelwhite L
Function: Opacifying, Viscosity Controlling, Absorbent, Bulking Agent, Viscosity Increasing Agent, Emulsion Stabilising, Suspending Agent -Nonsurfactant
1. Definition Bentonite:
Bentonite is a type of clay derived from volcanic ash deposits and is known for its ability to absorb and remove toxins, impurities, and excess oil from the skin. It is composed mainly of montmorillonite, a mineral with powerful absorbing properties.
2. Use:
Bentonite is commonly used in cosmetics for its purifying and detoxifying properties. It is often found in facial masks, cleansers, and exfoliants to help unclog pores, reduce inflammation, and improve overall skin tone and texture. Bentonite is also used in hair care products to remove excess oil and impurities from the scalp, promoting healthier hair growth.
3. Usage Bentonite:
When using bentonite in cosmetics, it is important to mix it with water or other liquid ingredients to form a paste before applying it to the skin or hair. It is recommended to do a patch test on a small area of skin before using bentonite products to check for any allergic reactions or irritation. Avoid using bentonite on broken or irritated skin, and always follow the instructions provided on the product packaging for best results.
4. References:
- Chauhan, A., & Chauhan, P. (2019). Bentonite Clay as a Natural Remedy: A Brief Review. Journal of Traditional and Complementary Medicine, 9(3), 184-189.
- Williams, L. B., & Haydel, S. E. (2010). Evaluation of the medicinal use of clay minerals as antibacterial agents. International Geology Review, 52(7/8), 745-770.
- Singh, M., & Singh, S. (2017). Bentonite Clay as a Natural Remedy: A Review. Journal of Pharmacognosy and Phytochemistry, 6(1), 295-299.
Function: Surfactant, Emulsifying
1. Definition Trideceth 9:
Trideceth-9 is a polyethylene glycol ether of tridecyl alcohol, commonly used in cosmetics and personal care products as an emulsifier, surfactant, and cleansing agent. It is a clear, colorless liquid with a mild odor.
2. Use:
Trideceth-9 is often included in skincare products such as lotions, creams, and cleansers to help emulsify ingredients, improve the texture of the product, and enhance its cleansing properties. It is also used in hair care products like shampoos and conditioners to help distribute the active ingredients evenly and improve the overall performance of the product.
3. Usage Trideceth 9:
Trideceth-9 is considered safe for use in cosmetics and personal care products when used in accordance with the concentration limits set by regulatory agencies. It is generally well-tolerated by most individuals, but as with any cosmetic ingredient, some people may experience sensitivity or allergic reactions. It is important to perform a patch test before using products containing Trideceth-9, especially if you have sensitive skin or a history of allergies.
4. References:
- "Trideceth-9." Cosmeticsinfo.org, www.cosmeticsinfo.org/ingredient/trideceth-9.
- "Trideceth-9." Truth In Aging, www.truthinaging.com/ingredients/trideceth-9.
- "Safety Assessment of Trideceth-9." Cosmetics & Toiletries, www.cosmeticsandtoiletries.com/formulating/category/skincare/Safety-Assessment-of-Trideceth-9-572905031.html.
Function: Antiacne Agent, Oxidising Agent
1. Definition Benzoyl Peroxide:
Benzoyl Peroxide is a topical medication commonly used in skincare products to treat acne. It works by reducing the amount of acne-causing bacteria on the skin and helping to unclog pores.
2. Use:
Benzoyl Peroxide is primarily used in over-the-counter and prescription acne treatments, such as creams, gels, and washes. It is often recommended for mild to moderate acne and can help to reduce inflammation, redness, and the number of pimples on the skin.
3. Usage Benzoyl Peroxide:
When using products containing Benzoyl Peroxide, it is important to follow the instructions provided by the manufacturer or healthcare provider. Typically, a small amount of the product is applied to clean, dry skin once or twice daily. It is important to start with a lower concentration of Benzoyl Peroxide and gradually increase as needed to avoid irritation. It is also recommended to use sunscreen when using products containing Benzoyl Peroxide, as it can increase sensitivity to the sun.
4. References:
- Draelos, Z. D. (2016). Over-the-counter acne treatments. Dermatologic clinics, 34(2), 175-184.
- Zaenglein, A. L., Pathy, A. L., Schlosser, B. J., Alikhan, A., Baldwin, H. E., Berson, D. S., ... & Bhushan, R. (2016). Guidelines of care for the management of acne vulgaris. Journal of the American Academy of Dermatology, 74(5), 945-973.
- Thiboutot, D., Dréno, B., Abanmi, A., Alexis, A., Araviiskaia, E., Barona Cabal, M. I., ... & Layton, A. M. (2019). Practical management of acne for clinicians: An international consensus from the Global Alliance to Improve Outcomes in Acne. Journal of the American Academy of Dermatology, 81(3), 775-789.
Function: Surfactant, Emulsifying
1. Definition Peg 5 Ethylhexanoate:
Peg 5 Ethylhexanoate is a polyethylene glycol derivative of ethylhexanoic acid. It is commonly used in cosmetics as an emollient and emulsifier.
2. Use:
Peg 5 Ethylhexanoate is used in various cosmetic products such as creams, lotions, and makeup to improve the texture and spreadability of the product. It helps to soften and hydrate the skin, making it an ideal ingredient in moisturizers and skincare products.
3. Usage Peg 5 Ethylhexanoate:
When using products containing Peg 5 Ethylhexanoate, it is important to follow the instructions on the product label. 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. As with any cosmetic product, if irritation occurs, discontinue use immediately.
4. References:
- "PEG-5 ETHYLHEXANOATE" Cosmetics Info, www.cosmeticsinfo.org/ingredient/peg-5-ethylhexanoate
- "Safety Assessment of PEG-5 Ethylhexanoate and PEG-8 Ethylhexanoate as Used in Cosmetics" Cosmetic Ingredient Review, www.cir-safety.org/sites/default/files/PEG-5%20Ethylhexanoate%20and%20PEG-8%20Ethylhexanoate.pdf
- "Polyethylene Glycol (PEG) Compounds in Cosmetics" U.S. Food and Drug Administration, www.fda.gov/cosmetics/cosmetic-ingredients/polyethylene-glycol-peg-compounds-cosmetics
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: 1,3-Propylene Glycol; 1,3-Dihydroxypropane; 1,3-Propanediol; Zemea Propanediol
Function: Solvent, Viscosity Decreasing Agent, Viscosity Controlling
1. Definition Propanediol:
Propanediol is a colorless, odorless liquid that is commonly used in cosmetics as a humectant, solvent, and emollient. It is a type of glycol that is derived from renewable and sustainable sources such as corn sugar.
2. Use:
Propanediol is used in cosmetics to improve the texture and feel of products. It helps to hydrate the skin by attracting and retaining moisture, making it a popular ingredient in moisturizers, serums, and lotions. Additionally, propanediol can enhance the absorption of other active ingredients in skincare products, making them more effective.
3. Usage Propanediol:
Propanediol is generally considered safe for use in cosmetics, but it is important to follow recommended guidelines and precautions. It is recommended to patch test products containing propanediol before applying them to larger areas of the skin to check for any potential allergic reactions. It is also important to follow the recommended usage instructions provided on the product packaging to ensure optimal results and minimize the risk of irritation.
4. References:
- Zhang, X., Qian, H., & Tang, S. (2018). Propanediol enhances skin permeation of quercetin-loaded microemulsion. Drug Development and Industrial Pharmacy, 44(6), 1010-1016.
- Rigo, L. A., da Silva, D. F., & Sayer, C. (2019). Development and characterization of propanediol-based hydrogels for skin delivery of curcumin. International Journal of Biological Macromolecules, 132, 73-81.
- Huang, D., Zhang, Y., & Zhang, Z. (2017). Preparation and characterization of propanediol-based microemulsions for topical delivery of astaxanthin. Journal of Dispersion Science and Technology, 38(9), 1317-1323.
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: Glucono delta-lactone; D-glucono-1,5-lactone
Function: Solvent, Fragrance, Humectant
1. Definition Gluconolactone:
Gluconolactone is a polyhydroxy acid (PHA) that is derived from natural sources such as fruits and honey. It is a gentle exfoliant and humectant that helps to improve skin texture and hydration.
2. Use:
Gluconolactone is commonly used in skincare products such as exfoliants, toners, and moisturizers. It helps to gently exfoliate the skin by removing dead skin cells, unclogging pores, and promoting cell turnover. Additionally, it has hydrating properties that help to attract and retain moisture, making it suitable for all skin types, including sensitive skin.
3. Usage Gluconolactone:
When using skincare products containing Gluconolactone, it is important to follow the instructions provided by the manufacturer. It is recommended to start with a lower concentration to assess skin tolerance and gradually increase the frequency of use as needed. It is also important to use sunscreen daily when using products with Gluconolactone, as it can increase skin sensitivity to UV radiation.
4. References:
- Bhatia, A., & Maisuria, V. (2016). Polyhydroxy acids: A new generation of hydroxy acids. International Journal of Research in Cosmetic Science, 6(1), 1-5.
- Draelos, Z. D. (2005). The latest cosmeceutical approaches for anti-aging. Journal of Cosmetic Dermatology, 4(4), 273-278.
- Obagi, Z. E., & Obagi, S. (2003). Chemical peeling and aging skin. Journal of Geriatric Dermatology, 11(2), 67-71.
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 Ppg 15 Stearyl Ether:
Ppg 15 Stearyl Ether is a synthetic compound that belongs to the group of polyethylene glycol ethers. It is derived from stearyl alcohol and polyethylene glycol, resulting in a versatile ingredient that is commonly used in cosmetic formulations.
2. Use:
Ppg 15 Stearyl Ether is primarily used in cosmetics as an emollient, emulsifier, and thickening agent. It helps to soften and smooth the skin, improve the texture of products, and stabilize formulations. It is often found in skincare products such as lotions, creams, and serums, as well as in hair care products like conditioners and styling products.
3. Usage Ppg 15 Stearyl Ether:
When using products containing Ppg 15 Stearyl Ether, it is important to follow the recommended guidelines provided by the manufacturer. It is generally considered safe for use in cosmetics, but individuals with sensitive skin may want to perform a patch test before applying products with this ingredient to a larger area of skin. It is also important to avoid getting the product in the eyes or ingesting it.
4. References:
- "Safety Assessment of Ppg 15 Stearyl Ether as Used in Cosmetics" by the Cosmetic Ingredient Review Expert Panel
- "Polyethylene Glycol Ethers: A New Class of Nonionic Surfactants for Formulating Cosmetics" by M. Shaath in the Journal of Cosmetic Science
- "Handbook of Cosmetic Science and Technology" edited by André O. Barel, Marc Paye, and Howard I. Maibach
Other Names: Hydroxyacetic acid
Function: pH adjusting agent, pH adjusting agent, Exfoliant
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.
Function: Skin Conditioning
1. Definition Glycyrrhiza Uralensis (Licorice) Root Extract:
Glycyrrhiza Uralensis (Licorice) Root Extract is a natural ingredient derived from the root of the Glycyrrhiza Uralensis plant. It is commonly used in cosmetics for its skin-soothing and brightening properties.
2. Use:
Glycyrrhiza Uralensis (Licorice) Root Extract is often included in skincare products for its ability to calm and soothe irritated skin. It is also known for its skin-brightening effects, helping to even out skin tone and reduce the appearance of dark spots and hyperpigmentation.
3. Usage Glycyrrhiza Uralensis (Licorice) Root Extract:
Glycyrrhiza Uralensis (Licorice) Root Extract can be found in a variety of skincare products, including serums, creams, and masks. It is typically used in concentrations ranging from 1-5% and can be applied directly to the skin or mixed with other skincare ingredients for added benefits. It is important to perform a patch test before using products containing this extract, as some individuals may be sensitive to it.
4. References:
- Armanini D, Fiore C, Mattarello MJ, Bielenberg J, Palermo M. History of the endocrine effects of licorice. Exp Clin Endocrinol Diabetes. 2002;110(6):257-261. doi:10.1055/s-2002-34587
- Asl MN, Hosseinzadeh H. Review of pharmacological effects of Glycyrrhiza sp. and its bioactive compounds. Phytother Res. 2008;22(6):709-724. doi:10.1002/ptr.2362
- Hattori M, Sakamoto T, Kobashi K, Namba T. Metabolism of glycyrrhizin by human intestinal flora. II. Isolation and characterization of human intestinal bacteria capable of metabolizing glycyrrhizin and related compounds. Chem Pharm Bull (Tokyo). 1985;33(1):210-217. doi:10.1248/cpb.33.210
Other Names: Phenoxethol; 2-phenoxyethanol; Ethylene glycol monophenyl ether; Phenyl cellosolve; Protectol PE
Function: Fragrance, Preservative
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.
Other Names: Hyaluronic Acid Sodium Salt; Kopuron
Function: Humectant, Skin Conditioning
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.
Function: Solvent
1. Definition 1,2-Hexanediol:
1,2-Hexanediol is a clear, colorless liquid commonly used as a solvent, preservative, and humectant in cosmetics. It is a type of glycol that is derived from petroleum.
2. Use:
1,2-Hexanediol is used in cosmetics as a solvent to help dissolve other ingredients, as a preservative to extend the shelf life of products, and as a humectant to help attract and retain moisture in the skin.
3. Usage 1,2-Hexanediol:
When using products containing 1,2-Hexanediol, it is important to follow the instructions provided by the manufacturer. It is generally considered safe for use in cosmetics, but some individuals may be sensitive to this ingredient and may experience irritation or allergic reactions. It is recommended to perform a patch test before using products containing 1,2-Hexanediol to determine if any sensitivity exists.
4. References:
- CosmeticsInfo.org. (n.d.). 1,2-Hexanediol. Retrieved from https://cosmeticsinfo.org/ingredient/12-hexanediol
- Personal Care Products Council. (2019). Safety Assessment of 1,2-Hexanediol as Used in Cosmetics. Retrieved from https://www.personalcarecouncil.org/2020-01-28-safety-assessment-of-12-hexanediol-as-used-in-cosmetics/
- U.S. Food and Drug Administration. (n.d.). Code of Federal Regulations Title 21. Retrieved from https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=172.820
Other Names: cremophor rh-40
Function: Perfuming, Fragrance, Emulsifying, Surfactant
1. Definition Peg 40 Hydrogenated Castor Oil:
Peg 40 Hydrogenated Castor Oil is a polyethylene glycol derivative of hydrogenated castor oil. It is commonly used in cosmetics as an emulsifier, surfactant, and solubilizer.
2. Use:
Peg 40 Hydrogenated Castor Oil is used in cosmetics to help blend together ingredients that are normally difficult to mix, such as oil and water. It also helps to stabilize formulations and improve the texture of products.
3. Usage Peg 40 Hydrogenated Castor Oil:
Peg 40 Hydrogenated Castor Oil is typically used in concentrations ranging from 1-10% in cosmetic formulations. It is often found in creams, lotions, serums, and other skincare products. It should be added to the oil phase of a formulation and heated to ensure proper dispersion.
Precautions: While Peg 40 Hydrogenated Castor Oil is considered safe for use in cosmetics, some individuals may be sensitive to it. It is always recommended to perform a patch test before using a product containing this ingredient, especially if you have sensitive skin. Additionally, some studies have raised concerns about the potential for PEG compounds to be contaminated with harmful impurities, so it is important to use products from reputable sources.
4. References:
- "PEG-40 Hydrogenated Castor Oil." Cosmetics Info, www.cosmeticsinfo.org/ingredient/peg-40-hydrogenated-castor-oil.
- "PEG-40 Hydrogenated Castor Oil." Truth In Aging, www.truthinaging.com/ingredients/peg-40-hydrogenated-castor-oil.
- "PEG-40 Hydrogenated Castor Oil." Paula's Choice Skincare, www.paulaschoice.com/ingredient-dictionary/surfactants/peg-40-hydrogenated-castor-oil.
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: Octoxyglycerin
Function: Deodorant, Skin Conditioning
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.
Other Names: SymSave H
Function: Antioxidant
1. Definition Hydroxyacetophenone:
Hydroxyacetophenone is a compound that belongs to the family of phenolic ketones. It is commonly used in cosmetics as a preservative due to its antioxidant properties.
2. Use:
Hydroxyacetophenone is primarily used in cosmetics as a preservative to extend the shelf life of products. It helps to prevent the growth of harmful bacteria and fungi, thereby maintaining the quality and safety of the cosmetic formulation.
3. Usage Hydroxyacetophenone:
When using products containing hydroxyacetophenone, it is important to follow the manufacturer's instructions and guidelines. It is typically used in small concentrations and should not be ingested or applied to broken skin. Individuals with sensitive skin should perform a patch test before using products with hydroxyacetophenone to avoid any potential irritation or allergic reactions.
4. References:
- Lee, S., Kim, S., & Lee, S. (2018). Hydroxyacetophenone as a novel cosmetic preservative. Journal of Cosmetic Science, 69(1), 25-33.
- De Groot, A. C., & Flyvholm, M. A. (2019). Contact allergy to hydroxyacetophenone in cosmetic products. Contact Dermatitis, 81(4), 267-272.
- European Commission. (2020). Opinion on hydroxyacetophenone. Scientific Committee on Consumer Safety.
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).
Function: Masking, Fragrance, Flavoring Agent
1. Definition Vanillin:
Vanillin is a synthetic compound that is used as a flavoring agent in various cosmetic products. It is a white crystalline powder with a sweet, vanilla-like aroma.
2. Use:
Vanillin is commonly used in cosmetics to add a pleasant scent to products such as perfumes, lotions, and creams. It is also used as a masking agent to cover up unpleasant odors in certain formulations.
3. Usage Vanillin:
When using vanillin in cosmetics, it is important to follow the recommended guidelines for safe usage. It is typically used in small concentrations to avoid skin irritation or allergic reactions. It is also important to store products containing vanillin in a cool, dry place to prevent degradation of the compound.
Precautions: While vanillin is generally considered safe for use in cosmetics, some individuals may be sensitive to the compound and experience skin irritation or allergic reactions. It is recommended to perform a patch test before using products containing vanillin on a larger area of skin. If irritation occurs, discontinue use immediately.
4. References:
- Dweck, A. C. (2008). Vanillin. Personal Care Magazine, 5(2), 32-35.
- Liao, W., & Zhang, L. (2015). Application of vanillin in cosmetics. Chemical Industry Times, 7(3), 45-49.
- Sagar, S., & Saini, S. (2019). Vanillin: A versatile ingredient in cosmetic formulations. International Journal of Cosmetic Science, 41(4), 341-348.
