KS Cosmetology cheat sheet

Sanitizing reduces pathogens on surfaces to a safe level; disinfecting destroys most pathogens on hard, nonporous implements; sterilizing destroys all microbial life including spores and is required for items that penetrate skin.

An EPA-registered hospital-strength disinfectant must be mixed and used per label directions; most quats-based products require 10 minutes of full immersion for implements.

Blood and body-fluid spills: wear gloves, absorb with disposable towel, clean with soap and water, then disinfect with an EPA-registered tuberculocidal product labeled for bloodborne pathogens.

Single-use items (nail files, orangewood sticks, cotton, neck strips, razor blades) are discarded after one client and never disinfected for reuse.

Porous implements (wood, foam, terry cloth) cannot be reliably disinfected; they are single-use only.

Disinfectant containers must be labeled, covered, and changed at least daily or when visibly soiled; test strips verify quat concentration.

Hand washing with soap and warm running water for at least 20 seconds is required before and after each client; hand sanitizer is not a substitute when hands are visibly soiled.

State barbering and cosmetology rules typically require a bloodborne-pathogen training certificate and posted licenses; infection control violations are the most common cause of board citations.

Herpes simplex, tinea (ringworm), and HPV warts are contagious and are grounds for refusing service on affected skin; pediculosis (lice) also requires referral.

Hair is roughly 90% cortex, 6-8% cuticle, and 1-2% medulla by mass; the cortex contains the disulfide, salt, hydrogen, and peptide bonds that drive styling and chemical services.

pH scale: hair and scalp are naturally pH 4.5-5.5; alkaline products (pH above 7) swell the cuticle and open it, acidic products (pH below 7) close and compact the cuticle.

Hair texture is the diameter of a single strand (fine, medium, coarse); density is the number of strands per square inch; porosity is the ability to absorb moisture.

Porosity classes: low porosity resists moisture and needs heat or alkaline help; high porosity absorbs fast but loses moisture and is prone to damage.

Elasticity test: wet a strand and stretch it; healthy hair stretches 50% and returns; hair that snaps indicates poor elasticity and should not receive a relaxer or bleach.

Scalp conditions: seborrheic dermatitis (yellowish scales, oily), pityriasis (dry flakes), tinea capitis (ringworm, contagious, refer), folliculitis (infected follicles, refer).

Shampoos: clarifying removes buildup, moisturizing adds humectants, medicated treats dandruff with zinc pyrithione, ketoconazole, or salicylic acid.

Conditioners: surface conditioners coat and smooth the cuticle; penetrating conditioners (hydrolyzed protein, fatty alcohols, oils) enter the cortex and improve elasticity temporarily.

Protein treatments temporarily fill gaps in the cortex; overuse causes brittleness, so alternate with moisture treatments.

Line: a section of hair that forms a visual boundary; guideline (section) is the first cut strand that determines length for the rest of the section.

Elevation angles: 0 degrees = one length (blunt, heavy perimeter); 45 degrees = graduated (stacked, builds weight); 90 degrees = uniform layers (even distribution); 180 degrees = long layers (removes weight, adds movement).

Distribution: natural fall follows the head shape; shifted distribution moves hair outside its natural position to build or remove weight.

Shears: cutting above the fingers is a blunt or club cut; slide cutting and point cutting are texturizing techniques that soften a line without changing length.

Razor cutting produces softer, tapered ends and works best on medium to coarse hair with some texture; it is avoided on fine or highly porous hair.

Clippers and trimmers: guards numbered by length; a #1 guard leaves 1/8 inch, #2 leaves 1/4 inch, #3 leaves 3/8 inch, #4 leaves 1/2 inch.

Cross-checking the opposite section confirms balance; tension must be consistent because stretched versus relaxed sections create uneven lines.

Neckline and perimeter shapes: square, round, and tapered; the taper blends the hairline into the longer length above it.

Cutting wet hair yields a shorter dry result on curly and wavy textures; cut curly hair dry or allow for shrinkage of 1-3 inches.

The law of color: primary colors are red, yellow, blue; secondary colors (orange, green, violet) are made by mixing two primaries; complementary colors sit opposite on the color wheel and neutralize each other.

Levels run 1 (black) to 10 (lightest blonde); a color's level is the lightness or darkness, its tone is the underlying warm or cool cast.

Developer (hydrogen peroxide) volumes: 10 volume (3%) deposits only, 20 volume (6%) lifts 1-2 levels and deposits, 30 volume (9%) lifts 2-3 levels, 40 volume (12%) lifts 3-4 levels.

Permanent color requires a developer and an alkaline agent (ammonia or MEA) to open the cuticle and an oxidative dye to form color molecules inside the cortex.

Demi-permanent color uses a low-volume developer (usually 10 volume) and no ammonia; it deposits without lifting and fades over 4-6 weeks.

Semi-permanent color is a direct dye with no developer; it coats the cuticle and washes out in 4-6 shampoos.

Bleach (lightener) removes pigment; on a level 5 base, the stages of lightening run red, red-orange, orange, yellow-orange, yellow, pale yellow, then pale yellow-white.

Patch test 24-48 hours before any oxidative color; strand test on the client's hair to predict timing and result; always read the manufacturer's mixing ratio.

Toning after lightening uses a low-volume deposit color to cancel unwanted warmth; violet neutralizes yellow, blue neutralizes orange, green neutralizes red.

Permanent waving breaks disulfide bonds with a reducing agent (ammonium thioglycolate for alkaline waves, glyceryl monothioglycolate for acid waves), reshapes the hair around a rod, then rebuilds the bonds with a neutralizer (hydrogen peroxide or sodium bromate).

Alkaline waves have pH 9.0-9.6, process without heat, and work on resistant hair; acid waves have pH 6.5-7.0, require heat, and are gentler on damaged hair.

Rod size and shape control curl: small diameter gives tight curls; the rod's length and diameter must match the desired curl and the hair's length.

Processing time is set by the manufacturer and the hair's porosity; overprocessing causes breakage and a frizzy, mushy feel.

Relaxers: sodium hydroxide (lye, pH 12-14) is fast and strong; guanidine hydroxide (no-lye, pH 12-13) is gentler on the scalp but more drying; ammonium thioglycolate is used in thio relaxers.

Base and no-base relaxers: base cream protects the scalp but slows processing; no-base relaxers require careful application and a scalp free of abrasions.

Relaxer retouch application begins at the new growth and never overlaps previously relaxed hair; overlapping causes breakage and scalp burns.

Neutralizing shampoo lowers pH, stops the relaxer, and rebuilds disulfide bonds; a minimum of three lathers is typical, and the relaxer is rinsed thoroughly first.

A relaxer and a permanent wave on the same day is contraindicated; wait at least two weeks, and test elasticity before any chemical service.

Blow-dryer tension and angle set the shape: directing airflow down the shaft smooths the cuticle; lifting at the root builds volume.

Thermal tools: curling iron barrel size controls curl diameter; flat iron plate material affects heat distribution and shine (ceramic and tourmaline distribute heat evenly).

Heat protectants form a film that slows heat transfer and reduce moisture loss; apply before any thermal tool.

Setting lotions and mousses are film-formers that hold shape; gels give firmer hold and shine; pomades add weight and are used sparingly on fine hair.

Pin curls: a ridge curl is a flat pin curl with a closed center; a barrel curl is a stand-up pin curl; the direction of the stem sets the wave direction.

Finger waves require uniform ridge depth and alternating ridge and hollow; the stem determines the wave direction and the ridge is the high point.

Hair spray is a finishing product applied at 8-12 inches; closer application causes a wet, sticky spot.

Finishing: backcombing (teasing) creates volume at the base and must be smoothed over; backbrushing is gentler and works on shorter hair.

Updo balance: anchor pins at the base, secure the perimeter first, then fill the interior; hair must be dry and product-set to hold.

Nail anatomy: the nail plate is the visible nail; the nail bed is the skin beneath it; the matrix at the base produces new cells; the eponychium is the living skin at the base; the hyponychium seals the free edge.

Nail growth averages about 1/8 inch (3 mm) per month; fingernails grow faster than toenails, and growth slows with age and in cold weather.

Nail shapes: square, squoval, round, oval, and pointed; the shape must suit the client's natural nail and lifestyle.

Manicure tools: cuticle nippers remove dead tissue only; metal pushers are used gently; nipping living tissue is a contraindication.

Nail disorders: onychomycosis (fungal infection, refer), paronychia (bacterial infection, refer), onycholysis (separation, refer), and Beau's lines (trauma or illness).

Acrylic (liquid-and-powder) ratio: a proper bead is 1.5 parts powder to 1 part liquid; too wet causes shrinkage and lifting, too dry causes brittleness.

Gel polish cures under UV or LED light; UV lamps take longer than LED; both require a base and top coat and proper curing to avoid service breakdown.

Pedicure: soak, sanitize, exfoliate, and massage; use a single-use foot file or sanitize reusable tools; never use a credo blade on diabetic clients.

Nail art and polish: base coat prevents staining, and two thin coats of color dry faster than one thick coat.

Skin layers: epidermis (outer, avascular), dermis (contains collagen, elastin, nerves, glands), and subcutaneous layer (fat and insulation).

Skin types: normal, dry, oily, combination, and sensitive; skin conditions include dehydration, acne, rosacea, and hyperpigmentation.

Fitzpatrick scale types I-VI estimate sun sensitivity and guide treatment intensity; type I burns easily and type VI rarely burns.

Cleansing steps: cleanse, exfoliate (mechanical or chemical), tone, treat (serum), moisturize, and protect with SPF.

Chemical exfoliants: AHAs (glycolic, lactic) work on the surface and are water-soluble; BHAs (salicylic acid) are oil-soluble and penetrate pores.

Facial massage movements follow the direction of muscle and lymph flow; effleurage, petrissage, tapotement, and friction are the standard manipulations.

Contraindications for facial services: active infection, open lesions, recent chemical peel or waxing, and certain medications that cause photosensitivity.

Extractions: soften with warm steam, use gloved fingers or a comedone extractor, and never squeeze inflamed cysts.

High-frequency and galvanic devices require skin free of metal, no pacemaker, and no pregnancy for certain modalities.

Hair shaft layers: cuticle (outer scales), cortex (bulk, pigment, bonds), and medulla (central core, sometimes absent in fine hair).

The hair follicle is a tube in the dermis; the bulb at its base contains the matrix and melanocytes that produce pigment.

Growth phases: anagen (growth, 2-6 years), catagen (transition, 2-3 weeks), telogen (rest, about 3 months), then exogen (shedding).

The sebaceous gland attaches to the follicle and secretes sebum; the arrector pili muscle contracts to raise the hair.

Skin histology: the epidermis has five layers; the stratum corneum is the outermost and is composed of keratinized cells.

Bones of the skull and face relevant to styling: frontal, parietal, temporal, occipital, zygomatic, mandible, and maxilla.

Muscles of the face: frontalis, temporalis, masseter, orbicularis oculi, orbicularis oris, and platysma.

Nail unit: matrix, nail plate, nail bed, cuticle, eponychium, hyponychium, and lateral nail folds.

Melanin types: eumelanin (brown-black) and pheomelanin (red-yellow) determine natural hair color.

Matter: elements, compounds, and mixtures; a solution is a uniform mixture of solute in solvent; a suspension has undissolved particles; an emulsion combines oil and water with an emulsifier.

pH scale runs 0-14; below 7 is acidic, 7 is neutral, above 7 is alkaline; each unit is a tenfold change in hydrogen ion concentration.

Surfactants have a hydrophilic head and a lipophilic tail; they lift oil and dirt into water so it rinses away.

Oxidation-reduction: oxidizing agents (hydrogen peroxide, bleach) add oxygen or remove hydrogen; reducing agents (thioglycolate) add hydrogen and break disulfide bonds.

Chemical bonds in hair: disulfide (strongest, broken by perms and relaxers), salt (broken by water and pH), hydrogen (broken by water and heat), and peptide (broken only by chemical damage).

Alkanolamines such as monoethanolamine (MEA) replace ammonia in low-odor color and are alkaline.

Silicones (dimethicone, cyclomethicone) coat the cuticle and add slip; they can build up and require clarifying shampoo.

Humectants (glycerin, propylene glycol) attract water from the air; emollients (oils, fatty alcohols) soften and smooth the surface.

Product labels: active ingredients appear first; a preservative system is required in any product containing water to prevent microbial growth.