1. Part 2–The Science of Barbering
Chapter 8
Chemistry
A basic study of chemistry should provide students with the foundation to understand important principles such as physical and chemical changes in matter, the chemistry of water, and the pH scale. Such a foundation of understanding will help students to better comprehend the changes that take place in the hair during chemical services, how to mix solutions, or which hair product to select based on its composition and the desired outcome. Throughout this topic of study, it is recommended that instructors take every opportunity to link the chapter content with examples or situations that student barbers may encounter on the clinic floor or in the barbershop.
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2. Learning Objectives Define organic and inorganic chemistry.
Define matter and its states.
Define pH and understand the pH scale.
Explain the characteristics of emulsions, suspensions, and solutions.
Understand how the pH levels of hair products affect the hair and scalp.
Discuss cosmetic preparations used in barbering including shampoos, conditioners, rinses, and tonics.
Review with students.

3. Key Terms Chemistry Cosmetic Chemistry acids, alkalis (bases), salts
atoms, elements, molecules
chemical changes/properties
compounds and pure substances
inorganic chemistry
ion and ionization
matter
oxidation-reduction reaction
oxides
pH and pH scale
physical changes/mixtures/ properties
Cosmetic Chemistry
powders, solutions, suspensions, emulsions
acid-balanced, balancing, moisturizing, liquid-dry
surfactants
shampoo chemistry
shampoos
conditioners
rinses
tonics
scalp conditioners
Review with students.

4. Chemistry
Study of the composition, structure, and properties of matter and how matter changes under different chemical conditions.
Divisions
Organic chemistry: the study of substances containing carbon (all living things); most will burn; e.g. gasoline, synthetic fabrics, plastics.
Inorganic chemistry: the study of substances without carbon (substances that never were alive); most will not burn; e.g. metals, minerals, water, air.
Review with students.

5. Matter
Anything with physical and chemical properties that occupies space.
States of matter: solids, liquids, and gases.
Energy is not matter; e.g. visible light and color are forms of energy.
Review with students.
(Continued)

6. Matter Elements: pure chemical substances
Cannot be separated into simpler substances
The basic materials that make up all matter
Each has its own type of atom and letter symbol
Atoms: building blocks of all matter
Smallest part of an element that retains characteristics
Consist of protons, neutrons, and electrons
Molecules: formed when two or more atoms are joined by a chemical bond
Elemental: two or more atoms of same element
Compound: two or more atoms of different elements
Elements: basic materials of all matter
a. Cannot be separated into simpler substances by chemical means.
b. Ninety four of the 117 known elements occur naturally on Earth.
c. Each element is given a letter symbol such as O for oxygen, S for sulfur, and H for hydrogen.
Atoms: the basic building blocks of all matter.
a. The smallest part of an element that retains the characteristics of that element.
b. Consist of protons, neutrons, and electrons.
Molecules: formed by chemically joining two or more atoms; types: elemental and compound.
a. Elemental: chemical combinations of two or more atoms of the same element; example: oxygen (O2).
b. Compound: chemical combinations of two or more atoms of different elements; example: sodium chloride (table salt), is a compound molecule that is a chemical combination of one atom of sodium (Na) and one atom of chlorine (CI).
(Continued)

7. Matter
Changes in matter happen when energy is added or subtracted by temperature.
Physical properties: characteristics determined without chemical reaction or change in identity.
Color, odor, density, weight, melting point, boiling point, and hardness
Chemical properties: characteristics determined with a chemical reaction and change in identity.
Rusting iron and burning wood
Energy added or taken away through temperature or pressure change creates changes in the states of matter.
Example: Water changes according to changes in the temperature, but it is still water.
Ice: water in a solid state, with definite shape and volume.
Liquid: water has volume but no definite shape.
Steam: water is an example of a gas, with no volume or shape.
Plasma state: created when energy (electricity) is added to a gas; example: glow produced by fluorescent and neon light bulbs.
Physical properties: characteristics that can be determined without chemical reaction and change in the identity of a substance. Examples: color, odor, weight, density, melting point, boiling point, and hardness.
Chemical properties: characteristics that can only be determined with a chemical reaction and change in the identity of a substance. Examples: rusting iron and burning wood; oxidation creates a chemical change in both.

8. Matter–Physical and Chemical Changes
Physical change in matter does not form a new substance.
Ice melting to water
Temporary haircolor
Chemical change in matter creates change in the chemical composition of a substance.
Iron to rust
Wood to ashes
Permanent haircolor
Physical change of matter: Does not form a new substance; no chemical reactions or new chemicals formed in the process.
Example 1: ice melts to water.
Example 2: temporary haircolor physically adds color to the hair surface, but does not create a chemical change in the hair’s structure or color.
Chemical change of matter: Occurs with change in the chemical composition of a substance.
Example 1: rusting iron.
Example 2: permanent haircolor creates chemical change through oxidation. Oxidation creates chemical changes in the product, hair structure, and hair color, forming new chemicals in the process.

9. Matter–Pure Substances
All matter can be classified as either a pure substance or a physical mixture.
Pure substances
Fixed chemical composition, definite proportions, and distinct properties.
Elements and compounds are pure substances.
Elemental molecules contain two or more atoms of the same element that unite chemically; e.g. aluminum foil.
Compounds are combinations of two or more atoms of different elements united chemically with fixed chemical composition, definite proportions, and distinct properties as a result of a chemical reaction; e.g. water.
Pure substance: matter that has a fixed chemical composition, definite proportions, and distinct properties. Elements and compounds are pure substances.
a. Elemental molecules contain two or more atoms of the same element that unite chemically; example: aluminum foil, composed only of atoms of the element aluminum.
b. Chemical compounds are the result of a chemical reaction; combinations of two or more atoms of different elements united chemically with fixed chemical composition, definite proportions, and distinct properties. Example: water, a chemical compound of two hydrogen atoms and one oxygen atom
(Continued)

10. Matter–Pure Substances
Compound classifications
Oxides: compounds of any element combined with oxygen
Carbon + oxygen = carbon dioxide
Acids: compounds of hydrogen, a non-metal (such as nitrogen), and, sometimes, oxygen
Hydrogen + sulphur + oxygen = sulphuric acid
Bases (alkalis): compounds of hydrogen, a metal, and oxygen
Sodium + oxygen + hydrogen = sodium hydroxide
Salts: compounds formed by acid and base reactions
Water also produced by the reaction
Sodium + chloride = table salt
Four classifications of compounds
a. Oxides: compounds of any element combined with oxygen. Examples: One part carbon and two parts oxygen equal carbon dioxide. One part carbon and one part oxygen equal carbon monoxide.
b. Acids: compounds of hydrogen, a non-metal such as nitrogen, and, sometimes, oxygen; example: hydrogen + sulphur + oxygen = sulphuric acid.
c. Bases: also known as alkalis: compounds of hydrogen, a metal, and oxygen; example: sodium + oxygen + hydrogen = sodium hydroxide.
d. Salts: compounds formed by the reaction of acids and bases; water also produced by the reaction; examples: sodium chloride (table salt) and magnesium sulphate (Epsom salts).

11. Matter–Physical Mixtures
Combination of two or more substances united physically in any proportion without a fixed composition
A mixture that has its own functions, but does not lose the characteristics of the individual ingredients
Pure air: physical mixture of nitrogen and oxygen gases
Concrete: water, sand, gravel, and cement
Physical mixtures: Combination of two or more substances united physically in any proportion without a fixed composition.
Example: Pure air is a physical mixture of mostly nitrogen and oxygen gases.
Example: Concrete is composed of water, sand, gravel, and cement; a mixture with its own functions, but which does not lose the characteristics of the individual ingredients.

12. Water The most abundant and important chemical The universal solvent.
Comprises 75 percent of earth’s surface.
Makes up about 65 percent of the human body.
Has a boiling point of 212°F.
Purified through boiling, filtration, or distillation.
Soft water: rainwater or chemically softened; allows soaps and shampoos to lather freely.
Hard water: contains mineral substances that may inhibit lather formation.
Water (H2O) is the most abundant and important of all chemicals;
called the universal solvent. 1. Distilled or de-mineralized water is a non-conductor of electricity.
2. Water with certain mineral substances is a conductor of electricity.
Purification of water: boiling, filtration, or distillation.
a. Soft water: rainwater or chemically softened water; allows for better lathering; best choice for use in the barbershop.
b. Hard water: contains mineral substances, calcium and magnesium salts, that hinder lathering; may be softened by distillation or use of sodium carbonate or sodium phosphate.
Optional Activity: Use the following steps to have students perform the hard-water test using the school’s water supply.
a. Dissolve ¾ of an ounce of pure, powdered castile soap in a pint of distilled water. b. Use a second pint bottle and fill it halfway with tap water. c. Add about seven drops (0.5 milliliters) of the soap solution. d. Shake the bottle vigorously; if lather forms at once and persists, the water is very soft. e. If lather does not appear at once, add another 0.5 milliliters of soap solution; shake again; if an additional 0.5 milliliters of the soap solution is needed to produce a good lather, the water is hard and should be softened for hair services in the school. f. Prepare a small seal-able bag with the required amount of powdered castile soap for each student; have students test their water at home and discuss the results.

13. Water and pH Letters pH denote “potential hydrogen”.
pH: the relative degree of acidity or alkalinity of a substance.
pH scale: measures concentration of hydrogen ions in acidic and alkaline water-based solutions.
Pure water: 50% acidic, 50% alkaline = 7.0 pH.
Ions: an atom or molecule that carries an electrical charge.
Ionization: the separation of a substance into ions that have opposite electrical charges.
Water and pH
1. Letters pH denote potential hydrogen.
2. Term pH means the relative degree of acidity or alkalinity of a substance.
3. The pH scale measures the concentration of hydrogen ions in acidic and alkaline solutions.
4. Potential hydrogen and ions: ions are atoms or molecules that carry an electrical charge.
5. Ionization: the separation of a substance into ions that have opposite electrical charges. Anion: negatively charged ion; cation: positively charged ion.

14. Water–Ions and Ionization
In pure water, some water molecules ionize naturally into hydrogen ions and hydroxide ions.
The pH scale measures the ions; the hydrogen ion is acidic and the hydroxide ion is alkaline.
The ionization of water makes pH possible because only aqueous (water) solutions have pH.
Ionization
Makes pH possible; only aqueous (water) solutions have pH.
Non-aqueous solutions (alcohol or oil) do not have pH.
Pure water: Water molecules ionize naturally into hydrogen ions and hydroxide ions.
The pH scale measures the ions.
Hydrogen ion is acidic; hydroxide ion is alkaline.
Pure water contains equal hydrogen and hydroxide ions, making it neutral.
Pure water is 7 on the pH scale.
(Continued)

15. Water–Ions and Ionization
Non-aqueous solutions (alcohol or oil) do not have pH.
In pure water, every water molecule that ionizes produces one hydrogen ion and one hydroxide ion.
Pure water contains the same number of hydrogen ions as hydroxide ions, making it neutral.
Review with students.

16. The pH Scale The pH scale is a logarithmic scale with values that
range from 0 to 14; below 7 is acidic; 7 is neutral;
above 7 is alkaline.
One whole number equals a tenfold change in pH; e.g., a pH of 8 is 10 times more alkaline than a pH of 7.
Two whole numbers equals a hundredfold change (10 x 10); e.g., a pH of 9 is 100 times more alkaline than a pH of 7.
The average pH of hair and skin is 5.0 (range 4.5 to 5.5). Pure water (neutral) is 100 times more alkaline than hair and can cause it to swell up to 20 percent.
Symbol pH: represents the quantity or concentration of hydrogen ions in a solution.
pH values are arranged on a scale ranging from 0 to 14.
a. pH of 7: indicates a neutral solution.
b. pH below 7: indicates an acidic solution.
c. pH above 7: indicates an alkaline solution.
pH scale is a logarithmic scale.
a. A change of one whole number represents a tenfold change in pH.
b. Example: A pH of 8 is 10 times more alkaline than a pH of 7. A change of two whole numbers indicates a change of 10 times 10, or a hundredfold change. A pH of 9 is 100 times more alkaline than a pH of .
c. Example: pH range of hair and skin: 4.5 to 5.5. Pure water is 100 times more alkaline than hair and skin, although neutral on the pH scale; pure water can cause the hair to swell up to 20 percent.
(Continued)

17. The pH Scale Acids (pH below 7.0) Alkalis (pH above 7.0)
Turn litmus paper from blue to red.
Contract and harden the hair.
Tighten the skin.
Alkalis (pH above 7.0)
Turn litmus paper from red to blue.
Soften and swell the hair.
May dry the skin.
Acids and alkalis neutralize each other when mixed in equal proportions.
Acids
a. Owe their chemical reactivity to the hydrogen ion (H+).
b. pH below 7.
c. Taste sour.
d. Turn litmus paper from blue to red.
e. Contract and harden the hair; tighten the skin.
f. Example: H2O2 neutralizer used in permanent waving.
Alkalis
a. Owe their chemical reactivity to the hydroxide (OH¯) ion.
b. Terms: alkalis also known as bases.
c. pH above 7.
d. Taste bitter.
e. Feel slippery on the skin.
f. Turn litmus paper from red to blue.
g. Soften and swell the hair.
h. Example: Sodium hydroxide (lye); very strong alkali used in drain cleaners and chemical hair relaxers.
Acid-alkali neutralization reactions
a. Equal proportions of acids and alkalis mixed together neutralize each other to form water and salt.
b. Example: Equal amounts of hydrochloric acid and sodium hydroxide neutralize each other to form a solution of pure water and table salt.
c. Permanent waving neutralizing lotions and hydroxide hair relaxer neutralizing shampoos create same type of acid-alkali neutralization reaction.

18. Effects of pH Levels on Hair
Review with students.

19. Oxidation-Reduction Reactions
Oxidation: chemical reaction that combines an element or compound with oxygen to produce an oxide.
Heat is usually produced.
Exothermic: chemical reactions that give off heat.
Oxygen
Combined with a substance, oxidizes the substance.
Removed from a substance, reduces the substance.
Redox: simultaneous oxidation and reduction
E.g., when hydrogen peroxide is mixed with an oxidation haircolor, the haircolor gains oxygen while the hydrogen peroxide loses oxygen and is therefore reduced.
1. Oxidation: chemical reaction that combines an element or compound with oxygen to produce an oxide; some heat is usually produced.
a. Chemical reactions characterized by the giving off of heat: exothermic.
b. Example: exothermic permanent-waving lotions produce heat due to oxidation reaction; slow oxidation occurs in oxidation haircolors and permanent-wave neutralizers.
c. When oxygen is combined with a substance, the substance is oxidized.
2. Reduction reactions
a. Reduction: when oxygen is removed from a substance, the substance is reduced.
b. Oxidizing agent: the substance that releases oxygen.
c. Example: Hydrogen peroxide is an oxidizing agent; when mixed with an oxidation haircolor, the haircolor gains oxygen; hydrogen peroxide loses oxygen and is reduced.
3. Redox: A contraction for reduction-oxidation.
a. Oxidation and reduction always occur simultaneously.
b. In redox reactions, the oxidizer is reduced; the reducing agent is oxidized.
4. Other redox reactions
a. Oxidation may result from loss of hydrogen; reduction the result of added hydrogen. Example: Permanent waving solution contains thioglycolate acid. Waving solution breaks disulfide bonds in hair through a reduction reaction that adds hydrogen ions to the hair. Hair is reduced and perm solution is oxidized. After processing and rinsing, the neutralizer oxidizes the hair by removing hydrogen added with the waving solution. When the hair has oxidized, the neutralizer will be reduced in the process.

20. Cosmetic Chemistry Physical and chemical classifications
Powders: uniform mixtures of insoluble substances
Solutions: made by dissolving solid, liquid, or gas in another substance
Suspensions: uniform mixtures of two or more substances
Emulsions: suspensions held together by an emulsifier
Soaps: compounds of oils or fats and strong alkalis
Ointments: mix of petrolatum or wax and medicinal agent
The scientific study of the cosmetic products used in the barbering and cosmetology industries. Knowledge of products helps barbers to service their clientele in the barbershop. Physical and chemical classifications: powders, solutions, suspensions, emulsions, soaps, and ointments.
Powders: uniform mixtures of insoluble substances (inorganic, organic, and colloidal) that are properly blended, perfumed, and/or tinted.
Solutions: clear or transparent permanent mixtures of a solute and solvent that do not separate upon standing; classified as dilute, concentrated, or saturated solutions. Dilute: contains a small quantity of the solute in proportion to the quantity of solvent. Concentrated: contains a large quantity of the solute in proportion to the quantity of solvent. Saturated: will not dissolve or take up more solute than it already holds at a given temperature.
Suspensions: uniform mixtures of two or more substances. Particles can be seen with the naked eye. Not usually transparent; may be colored. Tend to separate over time; need to be shaken before use. Ex: hair tonics, salad dressing, calamine lotion, paint, and aerosol hair spray.
Emulsions: suspensions of one liquid dispersed in another, mixtures of two immiscible liquids held together by an emulsifying agent. Tend to separate over time; may remain stable for at least three years. Examples: Mayonnaise is an oil-in-water emulsion of two immiscible liquids. The egg yoke in mayonnaise emulsifies the oil droplets and disperses them uniformly in the water. Surfactants: substances that act as a bridge to allow oil and water to mix or emulsify.
Soaps: compounds made by mixing plant oils or animal fats with strong alkaline substances.
Ointments: semi-solid mixtures of organic substances; examples: lard, petrolatum, or wax, and a medicinal agent.

21. Shampoos Shampoo products Shampoo products should
Purpose is to cleanse the scalp and hair.
Should not contain harsh alkalis.
Shampoo products should
Cleanse the hair of oils, debris, and dirt.
Work efficiently in hard, as well as soft water.
Not irritate the eyes or skin.
Leave hair and scalp in their natural conditions.
Be selected based on hair and scalp condition.
Review with students.

22. Shampoo Chemistry
Shampoo products are typically emulsions that range between 4.5 and 7.5 on the pH scale.
Main ingredients are water and surfactants.
Additional ingredients
Moisturizers, preservatives, foam enhancers, perfumes, etc.
Listed on product label in descending order based on percentages within the shampoo formula.
Review with students.

23. Shampoo Chemistry–Molecules
Shampoo molecules are composed of a head and
tail, each with a special function.
Head: attracts water and repels dirt.
Tail: attracts dirt and repels water.
Review with students.
(Continued)

24. Shampoo Chemistry–Molecules
Review with students.

25. Shampoo Chemistry–Surfactants
Water + surfactants create shampoo molecules.
Surfactants (detergents) used determine shampoo classification; product may contain more than one to complement or offset properties of the base detergent.
e.g., a non-irritating amphoteric may be added to an anionic.
Anionics: commonly used; produces rich foam; e.g., sodium lauryl sulfate
Cationics: antibacterial action
Non-ionics: versatile; mild cleansing action
Amphoterics: aid in manageability; do not sting eyes
Surfactant (detergent) determines shampoo classification.
a. Classifications: anionic, cationic, nonionic, and amphoteric; more than one may be used in a formulation to complement or offset properties.
b. Anionics: most commonly used surfactants; examples: sodium lauryl sulfate and sodium laureth sulfate. Produce rich foam. Suitable for use in hard or soft water.
c. Cationics: made up of quaternary ammonium compounds. Most have some antibacterial action. Sometimes included in dandruff shampoos.
d. Nonionics: versatile, stable, and have the ability to resist shrinkage. Mild cleansing action; low incidence of irritation to human tissues. Example: cocamide (DEA, MEA) used in shampoo, lipstick, and permanent waving lotions.
e. Amphoterics: act as anionic or cationic substances, depending on solution’s pH. Tend to cling to hair and skin; aid in hair manageability. Possess germicidal properties. Used in several baby shampoos; do not sting the eyes. Identified on labels as Amphoteric I-20.

26. Shampoos–Categories
Liquid cream: thick liquids; contain soap, whitening agents, and oily compounds
Plain: usually clear, amber, or greenish yellow; seldom have lanolin or special agents; use on hair in good condition; may fade color
Liquid-dry: may be used when regular shampoo services are not an option; evaporate quickly
Powder or dry: used when a wet shampoo is not an option; sprinkled into hair and brushed out
Review with students.

27. designed for oily hair and scalp
Shampoos–Types
Acid-balanced pH level of hair or skin; mild, does not strip color; most can be used daily
Medicated contain medicinal agents; reduce dandruff and relieve scalp conditions
Moisturizing or Conditioning mild, cream shampoos containing humectants
Therapeutic Medicated contain chemicals or drugs effective for excessive dandruff; prescribed by a medical professional
Clarifying acidic ingredients cut through product, mineral, medication buildup; also used to prepare hair for chemical services
Organic contain natural, organic substances (herbs, plants); usually pH-balanced
Balancing
designed for oily hair and scalp
Color-enhancing contain basic colors; brighten, add slight color, eliminate unwanted tones
Types of shampoos
Acid-balanced: pH level of hair and skin; mild, does not strip color; most can be used daily.
Moisturizing or conditioning: mild, cream shampoos; contain moisturizing agents (humectants).
Clarifying: contain acidic ingredients to cut through product buildup; provide thorough cleansing; may prepare hair for chemical services and remove medication, or mineral buildup.
Balancing: designed for oily hair and scalp; wash away excess oiliness; do not dry out hair.
Medicated: contain medicinal agents; reduce dandruff and relieve scalp conditions; may affect color of tinted or lightened hair.
Therapeutic medicated: contain chemicals or drugs effective for excessive dandruff; prescribed.
Organic: contain natural, organic substances (herbs, plants, minerals); usually pH-balanced.
Color-enhancing: contain surfactants and basic colors; used to brighten, add slight color, and eliminate unwanted color tones.
Optional Activity: Have students create a wall chart on poster board with two columns: one for shampoos and one for conditioners. Then perform litmus tests on a variety of shampoo products used in the school and record test results on the chart. Leave conditioner column blank until after the topic is covered in class.

28. Conditioners Hair conditioners Moisturize the hair Scalp conditioners
Help to restore natural oils or proteins
Usual pH range of 3.0 to 5.5
Temporary remedy for dry or damaged hair
Excessive use or wrong type may cause buildup
Scalp conditioners
For general maintenance
To treat conditions requiring a medicinal product
Refers to either hair conditioners or scalp conditioners.
Hair conditioners: moisturize the hair; help to restore natural oils and proteins; pH of 3.0 to 5.5.
a. Temporary remedies for dry or damaged hair.
b. Excessive use or wrong type can cause product buildup; can make hair heavy or oily.
Scalp conditioners: for general maintenance or to treat conditions requiring a medicinal product.

29. Hair Conditioners–Types
Instant – Rinsed after 1 to 5
minutes
– Low pH
– Do not penetrate the
hair shaft – May add moisture,
protein, and oils
Examples: finishing, detangling, and cream rinses
Treatment or Repair
Moisturizing: uses humectants to draw or lock in moisture; rinsed after 10 to 20 minutes
Protein: cream or liquid form; partially replaces lost keratin in cortex to strengthen hair
Deep-conditioning: protein in cream moisturizer; strengthens and moisturizes.
Synthetic polymer: used on badly damaged hair
Leave-in
– Are not rinsed out of the hair
– May be designed in spray form for use with thermal tools
– May be included in chemical service products to help equalize the porosity of the hair shaft
Basic types of conditioners: instant, treatment or repair, and leave-in.
Instant: applied following a shampoo; rinsed after 1 to 5 minutes.
Low pH; does not penetrate hair shaft; may add oils, moisture, and sometimes protein.
Examples: finishing, detangling, and cream rinses.
Treatment or repair: include moisturizing, protein, deep-conditioning, and synthetic polymer conditioners.
Moisturizing: uses humectants to draw and lock in moisture; rinsed after 10 to 20 minutes.
Protein: cream or liquid form; partially replaces lost keratin in cortex to strengthen hair.
Deep-conditioning treatment: protein in cream moisturizer; strengthens and moisturizes.
Synthetic polymer: used on badly damaged hair; may prevent further breakage and correct excessive porosity.
Leave-in: designed for use with thermal tools or to equalize the porosity
of the hair shaft.

30. Scalp Conditioners–Types
Variety available for different purposes
Cream-based
Moisturizers and emollients soften and improve health of the scalp.
Medicated scalp lotions
Promote healing of the scalp.
Astringent tonics
Help remove oil accumulation on the scalp.
Review with students.

31. Rinses and Tonics
Rinses: agents used to cleanse or condition the hair and/or scalp; add highlights.
Basic categories
Water: used to wet and rinse hair during shampoo services.
Medicated: formulated to control minor dandruff and scalp conditions.
Bluing: contains base color to neutralize yellowish or dull, gray tones in hair.
Tonics: solutions that stimulate the scalp, help correct scalp conditions, or are grooming aids.
Types
Non-alcoholic: often contain an antiseptic solution and hair-grooming ingredients.
Alcohol-based: antiseptic and alcohol combination that acts as a mild astringent.
Cream tonics: emulsions of lanolin and mineral oils.
Oil mixture: alcohol with oil used as a grooming agent.
Review with students.

32. Other Cosmetic Preparations
Astringents, fresheners, and toners
Cleansing creams and lotions
Depilatories and epilators
Hairspray, hairdressings, styling aids
Masks and packs
Moisturizing and massage creams and lotions
Suntan lotions
Review with students.

33. U.S. Pharmacopeia–Common Ingredients
Alcohols • Hydrogen peroxide
Alkanolamines • Petrolatum
Alum • Phenol
Ammonia • Quats
Boric acid • Silicones
Formaldehyde • Witch hazel
Glycerin • Zinc oxide
Review with students.

34. What Did We Learn and Do Today?
Defined organic and inorganic chemistry.
Provided examples of states of matter.
Defined elements, compounds, and mixtures.
Compared solutions, suspensions, and emulsions.
Defined and discussed pH, the pH scale, reactions of solutions on hair and skin, and its relevance to products.
Review with students.
(Continued)

35. What Did We Learn and Do Today?
Discussed oxidation and reduction reactions.
Identified parts of the shampoo molecule; discussed shampoo classifications, types, and applications.
Identified and discussed conditioners, rinses, and tonics.
Reviewed other cosmetic preparations and ingredients.