Lipsticks are generally made by combining a water-insoluble dye with wax and a non-volatile oil. The wax provides a stable base for the lipstick and the oil alters the texture and makes it easy to apply, while providing a shiny finish. Common waxes include beeswax, carnauba wax and candelilla wax, while popular oils include
castor, olive and mineral oils, cocoa butter, lanolin, and petrolatum. Lip glosses, with their higher shine, contain more oils and less wax.
This results in a substance that is stiff, but will spread easily on lips. Because it’s water-insoluble, the lipstick won’t be dissolved by saliva or by any drink intake.
Mascara is one of the most popular cosmetic products on the market. The main ingredients of mascara are pigment, such as carbon or iron oxide to create the colour, polymer to create a film that coats the lashes, preservatives to extend the life of the product, and a thickening agent such as wax or oil.
Mascara can come in a water-free formula, which makes it waterproof and smudge proof, but more difficult to remove. Oil-water emulsion formulas are also used, which can smudge and run more readily, but are easier to wash off.
The basic ingredient of eye shadow is base filler or diluent, like mica, talc or sometimes kaolin clay. To make the eye shadow stick to your skin, binders such as magnesium or zinc compounds are added. Silica, nylon, dimethicone, boron nitride or bismuth oxychloride can be included to make the eye shadow easier to apply to the eyelids. Preservatives, such as glycol or tocopherol are also added. Then, of course, there is the pigment – eye shadow comes in a huge variety of colours.
Foundation can come as a loose powder, pressed powder or liquid. All types will generally contain a moisturiser, a colourant and a filler, which dilutes the pigment and also is supposed to fill in any fine lines or wrinkles. Various chemicals such as iron oxide, and titanium dioxide are used as pigments.
Talc, a soft mineral made from magnesium, silicon and oxygen, is a commonly used filler. Bismuth oxychloride is another common ingredient in foundation, used for the shimmering glow it gives to the wearer. Along with talc, it’s often found in ‘mineral makeups’ which are generally marketed as ‘natural’ and more suitable for sensitive skin, but bismuth oxychloride is not actually a naturally occurring form of bismuth. It’s a by-product of the lead smelting process, and has been found to be a skin irritant for some people. Talc can also cause skin irritation, and there has been some concern that it is also a carcinogen. This is however, regarded as a myth; prior to the regulation of talcum powder in 1973, talc could contain asbestos which might have contributed to an increased cancer risk.
Some doctors advise checking to see if diazolidinyl urea or imidazolidinyl urea has been used as a preservative in foundations, as this can give off formaldehyde, which can irritate the skin of some people.
Rouge, or blush is commonly used for adding colour to cheeks and face, and can come in many different forms – powder, gel, cream or liquid. A typical blush will contain a filler such as talc or stearic acid, and of course different pigments to provide the rosy complexion. Other concealing pigments can also be added to the mix to block the natural skin colour so the blush will appear stronger. These additives can include mica, zinc oxide or titanium oxide.
Fake tans change colour on contact with skin. The active ingredient in most fake tans is dihydroxyacetone, a colourless compound that darkens when it reacts with the amino acids in the top layer of skin. The colour change is permanent, but because skin cells are constantly being shed the tan is usually gone after about a
week. It is important to note that fake tans do not provide any sun protection, so individuals will still have to apply sun cream.
Shampoos and soaps
Shampoos and soaps clean by the use of surfactants (surface active agents). Surfactant molecules have both fat soluble (lipophilic) and water-soluble (hydrophilic) parts. The lipophilic part of the molecule sticks to oil and dirt, and the hydrophilic part allows water to then carry away the otherwise water-insoluble grime. Washing-up detergents work in the same way, although they are specially formulated to remove thick grease from plates.
Common surfactants come from a class of chemicals called straight-chain alkyl benzene sulphonates. Common types that can be seen in a shampoo’s ingredient list are ammonium lauryl sulphate or sodium lauryl sulphate. Tetrasodium EDTA is a chemical that is added to strip away metals like calcium (Ca) and magnesium (Mg) found in water which can affect the effectiveness of the surfactants.
Other chemicals, called cocamides are added to make the foamy lather expected from a shampoo. Cocamides can also act as emulsifiers. Cocamidopropyl betaine is added to get the thickness of the shampoo right. It is also an anti-static agent, and a humectant, which means it helps the hair to retain moisture.