topic 1

• Objectives


  • Identify the common chemicals of everyday cosmetics
  • Describe how certain ingredients in cosmetics affect our health
  • Appreciate acquired knowledge about cosmetics and apply such learnings as a well-informed consumer
• Cosmetics are a category of health and beauty products used to care for the face and body, or used to accentuate or change a person's appearance
• Cosmetics can refer to products used to care for the skin and body, as well as those used to add fragrance
• Range of cosmetics


  • Hair conditioner
  • Facial beauty creams
  • Toothpaste
• Cosmetics can confer health benefits
• Key ingredients in most cosmetics

  • Water
  • Emulsifiers
  • Preservatives
  • Thickeners
  • Moisturisers
  • Colours
  • Fragrances
• A typical cosmetic product contains anything from 15–50 ingredients
• On average, women use between 9 and 15 personal care products per day, leading to around 515 individual chemicals being placed on their skin daily through cosmetic use
• Most cosmetics contain a combination of core ingredients including water, emulsifier, preservative, thickener, emollient, color, fragrance, and pH stabilizers
• Water in cosmetics


  • Forms the basis of almost every type of cosmetic product
  • Acts as a solvent to dissolve other ingredients and forms emulsions for consistency
• Water used in cosmetics must be 'ultra-pure'—free from microbes, toxins, and pollutants
• Emulsifiers in cosmetics

  • Help to keep unlike substances (such as oil and water) from separating
  • Change the surface tension between water and oil to produce a homogeneous product
• Emulsifiers used in cosmetics

  • Polysorbates
  • Laureth-4
  • Potassium cetyl sulfate
• Preservatives in cosmetics


  • Extend shelf life and prevent the growth of microorganisms such as bacteria and fungi
  • Can be natural or synthetic, and their effectiveness depends on the formulation of the product
• Most microbes live in water

  Preservatives used in cosmetics need to be water-soluble to prevent microbial growth
• Preservatives used in cosmetics

  1. Can be natural or synthetic (man-made) and perform differently depending on the formulation of the product

  2. Some require low levels of around 0.01%, while others require levels as high as 5%
• Popular preservatives


  • parabens
  • benzyl alcohol
  • salicylic acid
  • formaldehyde
  • tetrasodium EDTA (ethylenediaminetetra-acetic acid)
• Consumers who purchase ‘preservative-free’ products should be aware of their shorter shelf life and be conscious of any changes to the look, feel or odour of the product that may indicate it has gone off
• Thickening agents

  1. Work to give products an appealing consistency

  2. Can come from four different chemical families: Lipid thickeners, Naturally derived thickeners, Mineral thickeners, Synthetic thickeners
• Lipid thickeners


  • Usually solid at room temperature but can be liquefied and added to cosmetic emulsions
  • Work by imparting their natural thickness to the formula
  • Examples include acetyl alcohol, stearic acid, and carnauba wax
• Naturally derived thickeners


  • Polymers that absorb water, causing them to swell up and increase the viscosity of a product
  • Examples include hydroxyethyl cellulose, guar gum, xanthan gum, and gelatin
• Mineral thickeners


  • Natural thickeners that absorb water and oils to increase viscosity, giving a different result to the final emulsion than the gums
  • Popular examples include magnesium aluminium silicate, silica, and bentonite
• Synthetic thickeners


  • Often used in lotion and cream products
  • The most common synthetic thickener is carbomer, an acrylic acid polymer that is water-swellable and can be used to form clear gels
  • Other examples include cetyl palmitate and ammonium acryloyldimethyltaurate
• Emollients

  • Softens the skin by preventing water loss
  • Used in a wide range of lipsticks, lotions, and cosmetics
  • Natural and synthetic chemicals work as emollients, including beeswax, olive oil, coconut oil, lanolin, petrolatum (petroleum jelly), mineral oil, glycerine, zinc oxide, butyl stearate, and diglycol laurate
• Colouring agents/pigments are used in cosmetics to accentuate or alter a person’s natural colouring
• Mineral ingredients for colouring

  • iron oxide
  • mica flakes
  • manganese
  • chromium oxide
  • coal tar
• Natural sources for colouring

  • plants such as beet powder
  • animals like the cochineal insect
• Common shimmering effects materials

  • mica
  • bismuth oxychloride
• Smell is one of the key factors in a consumer’s decision to purchase and/or use a cosmetic product
• Fragrances


  • No matter how effective a cosmetic may be, no one will want to use it if it smells unpleasant
  • Smell is one of the key factors in a consumer’s decision to purchase and/or use a product
  • Chemicals, both natural and synthetic, are added to cosmetics to provide an appealing fragrance
  • Even ‘unscented’ products may contain masking fragrances to mask the smell of other chemicals
  • The term ‘fragrance’ is often a generic term used by manufacturers, representing dozens or even hundreds of unlisted chemical compounds used to create the final individual fragrance
• Harmful chemicals found in everyday cosmetics

  • Cancer
  • Endocrine disorders affecting hormone production
  • Developmental delays
  • Neurological problems
• When a person uses cosmetics, their skin absorbs chemicals which can then enter the bloodstream. People might also inhale powders or ingest some cosmetics, for example, lip products
• Certain chemicals in makeup and cosmetic products can contain ingredients linked to serious health concerns such as cancer, endocrine disorders, developmental delays, and neurological problems
• Talc in makeup products may pose a health risk due to possible contamination with asbestos, a known cancer-forming chemical
• Triclosan in cosmetics may affect thyroid hormones and contribute to antibiotic resistance, with research ongoing on its long-term effects on skin cancer development
• Cosmetic eye products containing kohl may have high levels of lead, a harmful heavy metal for the body
• Skin lighteners may contain mercury, which can affect the nervous system, cause kidney damage, and harm a developing fetus. Thimerosal, a preservative in cosmetics, can also contain mercury
• Phthalates present in some nail polishes, hair sprays, and fragrances can unbalance hormones, particularly those working alongside estrogen, potentially linked to breast cancer
• Products containing phthalates


  • Perfumes, hair sprays, cleaning products, cosmetic products
• Phthalates can unbalance hormones, particularly those that work alongside estrogen, such as testosterone