KY Cosmetology cheat sheet

Hair fiber layers, outer to inner: cuticle (overlapping scales, protects), cortex (bulk of fiber, holds melanin and disulfide bonds, site of perming/coloring chemistry), medulla (central core, may be absent in fine hair).

Hair growth cycle: anagen (active growth, 2–7 years, roughly 85–90% of scalp hair at any time), catagen (transition, about 2–3 weeks), telogen (resting, about 3 months, then shedding).

Skin layers: epidermis (outermost, avascular, keratinocytes, melanocytes in basal layer), dermis (collagen, elastin, nerves, glands, follicles, blood vessels), subcutaneous/hypodermis (fat, insulation, cushioning).

Nail anatomy: nail plate over the nail bed; matrix produces the plate; cuticle (eponychium) seals the base; hyponychium seals the free edge; lunula is visible matrix; lateral folds are sidewalls.

pH scale 0–14: hair and skin are acidic (hair about 4.5–5.5, skin about 4.5–5.5); alkaline products swell and open the cuticle; acidic products contract and close it.

Disulfide bonds (cystine) give hair strength and are broken by reducing agents (permanent wave) and reformed by oxidation; hydrogen bonds are broken by water and reset by heat/roller setting.

Microbial classes: bacteria (cocci, bacilli, spirilla), fungi (molds, yeasts), viruses, and parasites; pathogens cause disease, nonpathogens do not; spores are the most resistant form.

Bacteria growth needs: warmth, moisture, food, and a suitable pH; binary fission doubles populations, so contaminated implements amplify risk quickly.

Melanin types: eumelanin (brown/black pigment) and pheomelanin (red/yellow pigment); their ratio and density determine natural hair color, and melanin is removed by lightening.

Draping order for shampoo or wet services: shampoo cape over a towel, neck strip between cape and skin; for chemical services use two towels plus a water-repellent cape so product never contacts skin.

Surfactant chemistry: the hydrophobic tail lifts sebum and soil, the hydrophilic head binds water; anionic surfactants (sulfates) clean strongly, nonionic/cationic formulas are milder and conditioning.

Conditioners work by cationic attraction to negatively charged hair, smoothing the cuticle, reducing static, and restoring moisture; they are applied mid-shaft to ends and rinsed per manufacturer time.

Hair texture (fine, medium, coarse) describes diameter; density describes hairs per square inch; porosity describes ability to absorb moisture - low porosity resists, high porosity absorbs and loses moisture quickly.

Cutting angles: 0 degrees (blunt, one-length), 45 degrees (graduated/layered), 90 degrees (uniform layers), 180 degrees (long layers); elevation controls where weight sits.

Cutting lines: horizontal (one length), diagonal (graduated), vertical (graduated layers); tension and section size must stay consistent or the cut will be uneven.

Wet cutting uses tension and natural fall; dry cutting reveals the true shape and is used for texturizing, point cutting, and slide cutting.

Blow-dry styling: direct airflow from scalp to ends to smooth the cuticle, keep the nozzle parallel to the section, and use cool air to set the shape.

Thermal tools: curling irons and flat irons should be used on dry hair; heat protection products and correct temperature by texture (lower for fine or damaged hair) reduce breakage.

Haircolor classification: temporary (large molecules coat the cuticle), semipermanent (small molecules enter cuticle, no lift, fades over shampoos), permanent (developer opens cuticle, dye intermediates enter cortex and oxidize into larger color molecules).

Permanent color requires an alkalizing agent (ammonia or a substitute) plus an oxidizing developer; developer volumes: 10 vol (3%) deposit only, 20 vol (6%) deposit with 1 level lift, 30 vol (9%) 2–3 levels lift, 40 vol (12%) up to 4 levels lift.

Law of color: primary colors are blue, red, yellow; secondary colors are orange (red+yellow), green (blue+yellow), violet (blue+red); complementary colors neutralize - blue cancels orange, green cancels red, violet cancels yellow.

Level system 1 (black) to 10 (lightest blonde); tone describes warmth or coolness; the developer choice and the natural level plus target level determine lift and deposit.

Patch test and strand test are standard pre-service checks; record formulas, developer, timing, and processing so results are reproducible.

Permanent wave chemistry: reducing agent (ammonium thioglycolate, pH about 9.0–9.5) breaks disulfide bonds; thio-free waves use cysteamine (pH about 6.5–7.0); neutralizer (hydrogen peroxide or sodium bromate) rebuilds bonds into the new shape.

Permanent wave wrapping: end papers control ends, tension is firm but not tight, and processing time depends on hair porosity, texture, and product strength; overprocessing causes curl loss and breakage.

Chemical relaxing: hydroxide relaxers (sodium, lithium, potassium, guanidine) are strongly alkaline and permanently straighten; ammonium thioglycolate (thio) relaxers are used for "no-lye" and mild relaxing; never use hydroxide and thio on the same hair.

Keratin smoothing treatments are temporary (weeks) protein-based coatings applied with heat; they are not straighteners and do not permanently alter disulfide bonds; formaldehyde-free formulas still require ventilation and PPE.

Skin types: normal, dry (alipidic, lacks oil), oily (seborrhea), combination (oily T-zone, drier cheeks), and sensitive (reacts easily, redness, stinging).

Skin analysis observes pore size, oiliness, texture, hydration, pigmentation, vascularity, and lesions; note contraindications such as active infection, open lesions, or recent peels before service.

Facial sequence: consultation and skin analysis, cleanse, exfoliate (mechanical or chemical), steam and extraction (softened comedones only), massage, mask, tone, moisturize, protect with SPF.

Massage movements: effleurage (gliding), petrissage (kneading), tapotement (percussion), friction (rubbing); direction follows muscle and lymph flow, and massage is contraindicated over infection or inflammation.

Waxing: warm wax low-melt for large areas, hard wax for sensitive areas; apply in direction of hair growth, remove against growth, hold skin taut, and never wax over irritated, sunburned, or recently exfoliated skin.

Tweezing and threading are temporary methods; laser and electrolysis are permanent or long-term hair reduction methods performed within scope and licensing rules.

Makeup color theory: complementary colors neutralize - green corrects redness, peach/orange corrects blue or dark circles, lavender corrects sallow yellow tones.

Foundation selection matches undertone (warm, cool, neutral) and shade to the jawline in natural light; test on the face, not the wrist.

Sanitation in skin care: single-use applicators, spatulas, and disposable wax strips; implements disinfected between clients; hands washed before and after each service.

Nail plate growth: about 3 mm per month on fingernails, toenails slower (about 1 mm per month); full fingernail replacement takes roughly 4–6 months.

Manicure sequence: sanitation, shape with file (one direction, no sawing), buff lightly, soak and soften cuticles, gently push back, trim only loose cuticle, massage, polish.

Pedicure: soak to soften, use a separate set of implements from manicure tools, file nails straight across with slightly rounded corners, and avoid cutting calluses or corns (restricted to licensed medical scope).

Nail shapes: square, squoval, round, oval, pointed; the shape should follow the natural free edge and avoid thinning the sidewalls.

Nail disorders: onychomycosis (fungal infection, thick yellowed crumbling nail), paronychia (bacterial infection of the nail fold, red swollen painful), onycholysis (separation of plate from bed), onychorrhexis (brittle splitting), leukonychia (white spots).

Do not service a client with a suspected infection, inflamed nail fold, or open wound; refer to a physician; never share files, buffers, or pus-containing implements without disinfection.

Nail enhancements: acrylics (liquid monomer + powder polymer), gels (photoinitiator cured by UV/LED), wraps; removal must follow manufacturer instructions to avoid plate damage.

Disinfection vs sterilization: disinfection kills most pathogens on surfaces and implements; sterilization destroys all microbial life including spores and is done with an autoclave.

Implements must be cleaned (soap and water, remove debris), then disinfected with an EPA-registered hospital-grade tuberculocidal disinfectant at the labeled contact time, then stored in a clean closed container.

Infection control hierarchy: cleaning removes visible debris; disinfection kills most pathogens; sterilization destroys all microorganisms including spores; sanitation reduces contamination on surfaces and hands.

EPA-registered hospital-grade disinfectant with tuberculocidal claim is the standard for implements that contact skin, hair, or nails; follow the label dilution and contact time (commonly 10 minutes).

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

Single-use items: nail files, buffers, wooden sticks, cotton, wax strips, and gloves cannot be disinfected and must be discarded after one client.

Blood and body fluid exposure: wear gloves, stop the service, clean the area, disinfect all contact surfaces, and dispose of contaminated materials in a sealed bag; report per employer policy.

Electrical safety: check cords and plugs, keep water away from outlets, use GFCI protection near sinks, and unplug tools before cleaning.

Chemical safety: read SDS (Safety Data Sheet) for every product; store chemicals in labeled original containers away from heat and light; never mix products unless the manufacturer directs.

Ergonomics: adjust chair and client height, keep wrists neutral, and alternate tasks to reduce repetitive strain injuries.

Salon ventilation and PPE: gloves for chemicals, aprons for bleaches and colors, and adequate airflow for ammonia, formaldehyde, and acrylic monomer vapors.

The Kentucky Board of Cosmetology regulates licensing of cosmetologists, nail technicians, estheticians, and salons; it adopts administrative regulations (201 KAR 12) covering licensure, sanitation, and scope.

A license must be displayed at the workstation; salons must hold a current salon license, and the salon license and employee licenses must be available for inspection.

Scope of practice: cosmetologists may perform hair, skin, and nail services within training; medical procedures such as diagnosing or treating disease, cutting living tissue, or removing skin lesions are outside scope and require referral.

Licensure paths include completing an approved program (commonly 1,500 hours for cosmetology) and passing the required examinations; renewal cycles and continuing education requirements follow Board rule and should be verified with the Board.

Sanitation rules mirror the infection-control standard: implements disinfected with an EPA-registered hospital-grade disinfectant, single-use items discarded, and hand washing required between clients.

Salon requirements include a sink with hot and cold running water, a covered waste container, adequate lighting and ventilation, and a separate area for chemical services.

Professional ethics: informed consent before chemical services, honest disclosure of pricing and possible outcomes, confidentiality of client information, and refusal of services contraindicated by health or sanitation.

Advertising and titles must be truthful; only licensed individuals may perform services for compensation, and unlicensed practice is a violation subject to Board discipline.

Inspection and discipline: Board inspectors may enter salons during business hours; violations can lead to fines, suspension, or revocation, and the licensee has a right to notice and a hearing.