Cosmetic Chemistry Atom: The smallest part of an element that possesses the characteristics of the element Molecule: The smallest particle of an element or compound that possesses all the properties of the element or compound Element: The basic unit of all matter. When two or more elements unite chemically, they form a compound . A mixture is a substance that is made up of two or more elements combined physically rather than chemically.
Acidity & Alkalinity
The pH (potential of hydrogen) of a substance refers to its degree of acidity or alkalinity, and is measured on a scale of 0 to 14. Anything below 7 is acidic.
The lower the pH number, the greater the degree of acidity.
Anything from 7 to 14 is alkaline. The higher the pH number, the greater the degree of alkalinity.
Although the precise neutral point on the scale is 7.0, the neutral range is considered to extend from pH 6.5 to 7.5.
Acidity & Alkalinity
The Acid Mantle is the protective barrier in the Epidermis. A combination of Sweat and Sebum (oil) which combines to defend the skin & body against invading bacteria and makes the skin waterproof.
It has a PH level between 4.5 - 6
Acidity & Alkalinity PH Scale
Chemistry as applied to Cosmetics
Cosmetics may be classified according to their use and function. Each type has a specific physical and chemical nature and the characteristics by which they can be recognised. The object in classifying cosmetics is to assist in their identification.
PHYSICAL AND CHEMICAL CLASSIFICATIONS OF COSMETICS
Powders are a uniform mixture of insoluble substances (inorganic, organic, and colloidal) that have been properly blended, perfumed, and/or tinted to produce a cosmetic that is free from coarse or gritty particles. Mixing and sifting are used in the process of making powders.
Suspensions are mixtures of one type of matter in another type of matter. The particles will be immiscible and have a tendency to separate on standing, making it necessary to shake or stir the product before use.
Eg: Calamine lotion, whipping cream, salad dressing, air brush
fluid, clouds, and smoke
Please note the directions will always say shake before use!!!
Ointments are semi-solid mixtures of organic substances (lard, petrolatum, wax) and a medicinal agent. No water is used. For the ointment to soften upon application, its melting point should be lower than body temperature (98.6 degrees Fahrenheit (37 degrees Celsius). Examples: Paw Paw Cream, Cold sore cream, Vaseline
Sticks are similar to ointments in that they are a mixture of organic substances (oils, waxes, petrolatum) poured into a mould to solidify. Sticks are firmer and harder than ointments. No water is present. Examples: lipstick, eye pencils, colour crayons
Pastes are soft, moist cosmetics that have a thick consistency. They are bound together with gum, starch, and sometimes water. If oil and fats are present, water is generally absent. The colloidal mill assists in the removal of grittiness from the paste. Examples: cream rouge, mud masque, lipstick pots.
Ointments, Sticks and Pastes
A solution is an evenly dispersed mixture of two or more kinds of molecules. For example, a solution is made by mixing a solute-solid (for example, a sugar cube) into a solvent (for example, water). A solute is any substance that dissolves into a liquid and forms a solution. A solvent is any substance that is able to dissolve another substance.
Solutions are clear mixtures of a solute and solvent that do not separate when left standing. (Miscible) Solutions are easily prepared by dissolving a powdered solute in a warm solvent and stirring at the same time. The solute can be separated from the solvent by applying heat and evaporating the solvent. A good solution in it’s original state should be clear and transparent; thus filtration is often necessary if the solution is cloudy.
Binders, emollients, plant extracts and thickeners are added to cosmetic solutions for application purposes.
Water is a universal solvent. It is capable of dissolving more substances than any other solvent. Oils, grain alcohol, and glycerine are frequently used as solvents. Solvents are classified as miscible or immiscible . Water, glycerine, and alcohol readily mix with each other; therefore, they are miscible (mixable). On the other hand, water and oil do not mix with each other; hence, they are immiscible (non-mixable).
There are Three Solution Classifications
Dilute Solution: contains a small quantity of the solute in proportion to the quantity of the solvent. Eg. Brush Cleaner, Toner, Rose Spray, Spray & Wipe, Cordial, Hair spray
Directions will usually say spray onto a surface or apply with a cotton pad.
Concentrate Solution: contains a large quantity of the solute in proportion to the quantity of solvent. Eg. Liquid foundation, cleansers, moisturisers, Hair gel
Directions will usually say pour a little on your hands emulsify and massage gently onto the skin, or hair or apply with a brush or sponge
Saturate Solution will not dissolve or take more of the solute than it already holds at a given temperature. Eg. Facial Scrub, Face Masques, Heavy Night Cream, Hair mud, Hair wax, Gel Eyeliner, Cream eyeshadow Directions as above.
Emulsions are formed when two or more immiscible (non-mixable) substances, such as oil and water, are united with the aid of a binder (gum) or an emulsifier (soap). If a suitable emulsifier and the proper techniques are used, the resulting emulsion will be stable. A stable emulsion can hold as much as 90% water. Depending on the balance between the liquids and solids, the emulsion may be cream, liquid, or semi-solid in character.
Emulsions basically fall into two different classes: oil-in-water (O/W) and water-in-oil (W/O).
In addition to the emulsifier, which coats the oil droplets and holds them in suspension, there may be a number of additional ingredients present such as binders, emollients, slip agents and plant extracts.
On a list of ingredients the oil and water is always in the top two ingredients followed by the binder. An emulsion may be oily liquid, cream or semi-solid in character
Oil-in-water (O/W) emulsions (Water will be first on the ingredients list) are made of small amount of oil droplets suspended in a large water base. Eg. Foundation, Moisturisers, cleansing lotions or creams.
Water-in-oil (W/O) emulsions (Oil will be first on the ingredients list) are formed with a small amount of water suspended in a larger oil base. These are usually much thicker and oilier than the O/W emulsions, Eg. hair grooming creams, cleansing creams, and cold creams.
Soaps are compounds formed when a mixture of fats and oils are fed into a tank of superheated water (which converts into fatty acids) and then purified by distillation.
Potassium hydroxide ( Caustic Potash) is mixed with the fatty acids to make soft soap or with sodium hydroxide (lye or caustic soda) to make hard soap.
During the process of making soap, glycerine is given off in steam as a by-product. Sodium Laureth Sulfate (an alkalis chemical derived from salt) is also added as a foaming agent and detergent.
A high quality soap is made from pure oils and fats and does not contain excessive alkalis, therefore lowering the PH levels.
To Classify Soap the original ingredients of Oil, Sodium Hydroxide, Sodium Laureth Sulfate, Potassium Hydroxide, will be listed on the top of the ingredients and directions will state that it will lather up (Please note that some organic products will say that the product lathers up but they may not contain soap, the lathering process may occur with plant extracts.
Eg. Cleansing Hair Sprays, Foaming cleansers Shampoos, hand and body wash
Eg. Beauty Bar soaps, Laundry soap, Household bar soap.
Classification Cosmetics for Makeup
Two forms of face powder are widely used in the salon: loose and compact (cake ). Both types have the same basic composition; compact powders are simply compressed and held together with binders so the cake will not crumble.
FACE POWDER consists of a powder base, mixed with a colouring agent (pigment) and perfume. A good face powder for a normal skin should possess the following qualities:
1. SLIP - gives a smooth feel to the skin. This quality is gained primarily (35% to79%) by the talc content, but zinc stearate or magnesium stearate may be added for additional slip.
2. COVERING POWDER - the balance between opacity (covering defects and skin shine) and transparency (allowing the natural appearance of the skin to show through). The two ingredients that provide the balance in most powders are zinc oxide and titanium dioxide.
3. ADHERENCY - determines how long the powder will remain on the face without needing to be touched up. Talc, zinc stearate, magnesium stearate and kaolin have adhesive qualities.
4. OTHER INGREDIENTS - include bactericides, colour, and perfume. Bactericide are added to inhibit growth of bacteria and preserve the product. The colours listed on the ingredient list should be FD & C (food, drug, and cosmetic) or D & C (drug and cosmetic) approved, indicating that the colours have been certified buy the Food and Drug Administration. Perfumes are added to increase the marketability of the product.
FOUNDATION MAKE-UP BASE
(Emulsions, Suspensions, Concentrate Solutions)
The purpose of foundation make up is to improve the appearance of the complexion by blending skin tones, covering blemishes, and creating a smooth, healthy glow. Many foundations contain barrier agents such as UV inhibitors, cellulose derivatives, and silicone to protect the complexion from light rays (artificial and natural), the wind and cold, and from dirt and debris.
CREAM AND STICK FOUNDATIONS (O/W Emulsion, Stick) are predominantly water, mineral oil, stearic acid, cetyl alcohol, propylene glycol, triethanolamine, lanolin derivatives, borax and insoluble pigments. Cream Foundations may also contain surfactants (detergents), emulsifiers, humectants, perfume, and preservatives such as paraben. The formulation of this product is generally suited for dry to normal skin and gives good coverage. They may come in pots, compacts or roll up sticks and could vary in density.
LIQUID FOUNDATIONS (Suspensions, Concentrate solutions) are mostly suspensions of minerals and organic and inorganic pigments in an alcohol and water solution. Most liquid foundations must be shaken before use, but bentonite is added as a binder to help keep the product blended. The formulation of this product is generally suited for clients with oily to normal skin conditions desiring light to natural-looking coverage.
CHEEK COLOUR - BLUSH
Cheek colour is classified as powder, paste or stick
POWDER CHEEK COLOUR (powder) is simply compact or cake powder with colouring added. The pigment ranges from 5% to 20% of the product.
CREAM CHEEK COLOURS fall into two categories: oil-based pastes or sticks. The oil-based formulations are combinations of pigments dispersed in an oil or fat base. Blends of waxes (carnauba wax and ozokerite) and oily liquids (isopropyl myristate and hexadecyl stearate) create a water-resistant product. In addition, cream cheek colours contain water, thickeners, and a variety of surfactants or detergents that enable particles to penetrate the hair follicles and cracks in the skin.
Lip colour is available in a variety of forms: creams, glosses, pencils, gels, and sticks. All are formulas of oils. waxes, and dyes.
Castor oil is the primary ingredient in lipsticks, accounting for approximately 65% of the product. Other oils used are olive, mineral, sesame, cocoa butter, petroleum, lecithin, and hydrogenated vegetable oils.
Waxes commonly included in the ingredients are paraffin, beeswax, carnauba (also used in car waxes), and candelilla wax.
Bromic acid, D & C Red No. 27, D & C Orange No. 17 Lake, and related dyes are examples of those often used as colouring agents.
EYE PENCILS Classification : Sticks
consist of a wax (paraffin) or hardened oil base (petrolatum) with a variety of additives to create colour. They are available in both soft and hard form for use on the eyebrow as well as the upper and lower eyelid. According to the American Medical Association, eye pencils should not be used to colour the inside border of the eyes because this can lead to infection of the lacrimal duct, tearing, blurring vision, and permanent pigmentation of the mucous membrane lining inside the eye.
Please always check the manufacturers instructions regarding inner eye use
are available in cream and powder form. The cream shadows are water based with oil, petrolatum, thickener, wax, perfume, preservatives, and colour added. Water resistant shadows have a solvent base such as mineral spirits. Powder shadows are composed much the same as pressed face powder ad powered cheek colour.
is available in tube and wand applicators. Both are polymer products that include water, wax, thickeners, film-formers, and preservatives in their formulation. The pigments in mascara must be inert (unable to combine with other elements) and usually are carbon black, carmine, ultramarine, chromium oxide, and iron oxides. Coal tar dyes are not permitted. Some wand mascaras contain rayon or nylon fibres to lengthen and thicken the hair fibres.
are available in liquid and cake form as well as the pencil form described earlier. In the ingredient list you will find alkanolamine (a fatty alcohol), cellulose, ether, polyvinylpyrrolidone, methylparaben, antioxidants, perfumes, and titanium dioxide.
Water or mixing mediums may be added to eye shadow powders to create eyeliner.