Cosmetology (Cosmetology License) cheat sheet

Cleaning removes visible debris; disinfection destroys most pathogens on nonporous surfaces; sterilization destroys all microbial life including spores.

Implements that may contact blood or body fluids require an EPA-registered hospital-grade disinfectant labeled tuberculocidal, used for the full label contact time.

Quaternary ammonium disinfectants must be diluted to label strength and verified with test strips; cloudy or contaminated solution is replaced.

Porous items (wooden sticks, emery boards, cotton, porous files) cannot be disinfected and are discarded after a single use.

Cleaning with soap and water must precede immersion in disinfectant, because hair, skin oils, and product residue inactivate most disinfectants.

Electrical implements are unplugged before cleaning and immersed only when the manufacturer states they are submersible.

Blood exposure procedure: stop the service, don gloves, apply pressure, clean with antiseptic, cover the wound, disinfect all contacted surfaces, and seal contaminated waste.

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

A product labeled only 'sanitizer' does not meet the standard for blood-contact implements, which require hospital-grade disinfection.

Elevation controls weight distribution: 0 degrees = one-length blunt, 45 degrees = graduated, 90 degrees = uniform layers, 180 degrees = long layers over a short interior.

Cutting lines are horizontal (no elevation change), vertical (builds graduation or layering), and diagonal (blends between the two).

Guidelines are stationary (one section cut first and followed by all others), traveling (the guideline moves with each section), or combination.

Blunt cuts create the heaviest perimeter weight; interior weight is reduced only by texturizing methods that leave the perimeter length intact.

Clipper guard numbers equal eighths of an inch: #1 = 1/8 in, #2 = 1/4 in, #3 = 3/8 in, #4 = 1/2 in.

Wet hair stretches and shrinks as it dries, so cutting wet with tension can yield a shorter finished result than planned.

Cross-checking means cutting again with partings perpendicular to the original sections to verify balance and symmetry.

Texturizing shears, razors, notching, slithering, and point cutting remove bulk; razor work requires a sharp blade and light pressure to avoid frayed ends.

The level system runs from 1 (black) to 10 (lightest blonde); natural level versus target level determines the developer strength required.

Developer volumes: 10 vol = 3%, 20 vol = 6%, 30 vol = 9%, 40 vol = 12% hydrogen peroxide; 20 vol lifts about one level, 30 vol two levels, 40 vol three levels.

Demi-permanent and deposit-only color uses low-volume developer (5-10 vol) and cannot lighten natural pigment.

Law of color: primaries are red, yellow, blue; secondaries are orange (red+yellow), green (blue+yellow), violet (red+blue); tertiary colors mix a primary with an adjacent secondary.

Melanin lightening stages progress red, red-orange, orange, gold, yellow, pale yellow; the exposed underlying pigment must be factored into the target formula.

Aniline-derivative tints require a patch test 24-48 hours before the first application and after any formula change, with the result documented.

Red pigment molecules are the smallest and fade fastest; blue molecules are the largest and fade slowest.

A filler is applied before depositing color darker than the natural level over lightened hair to replace missing warm tones and prevent muddy or green results.

Mixing ratio is typically 1:1 for permanent color, while high-lift blondes commonly use 1:2 with 40 volume developer.

Base placement controls volume: on-base = maximum volume, half off-base = medium volume, off-base = smooth, low-volume finish.

The blow-dryer nozzle is pointed down the hair shaft and held about 6 inches from the hair to keep the cuticle smooth and reduce frizz.

Smaller round brushes create more tension and tighter curl; larger barrels smooth and add volume with less curl.

Velcro rollers add volume without heat and are set on dry hair, as are thermal irons and curling irons.

Stand-up (barrel) pin curls produce volume and movement; flat pin curls produce smooth waves close to the head.

Diffusers spread airflow over a wider area to protect curl patterns and reduce frizz on wavy or curly hair.

Mousse adds volume with light hold, setting lotion adds firm hold for wet sets, silicone serums add shine, and hairspray provides final hold and humidity resistance.

Backcombing (teasing) builds volume by matting hair at the base and must be smoothed over; it stresses fragile or fine hair.

Alkaline waves use ammonium thioglycolate at pH 9.0-9.6; acid waves use glyceryl monothioglycolate at pH 7.0-7.5 and require added heat to process.

Permanent waving reduces disulfide bonds with a reducing agent, then rebuilds them in the new shape with a neutralizer of hydrogen peroxide or sodium bromate.

Finished curl diameter approximates rod diameter; smaller rods produce tighter curls and larger rods produce looser waves.

Wrapping methods include croquignole (ends to scalp, tighter curl), spiral (wrapped down the length), piggyback (two rods per section for long hair), and bricklay (offset pattern).

Sodium hydroxide relaxers (lye) run pH 12-14; no-lye relaxers use guanidine or lithium hydroxide; ammonium thioglycolate (thio) relaxers at about pH 9 require a hydrogen peroxide neutralizer.

Relaxer strength (mild, regular, super) is selected by hair texture and resistance; super strength is not used on fine or previously relaxed hair.

A retouch is applied to new growth only and is never pulled through previously relaxed hair, which would over-process and break.

Metallic salts, abrasions on the scalp, and a history of adverse reactions contraindicate chemical texture services; a strand test precedes the service.

Over-processing appears as gumminess, excessive stretching, or breakage, and the neutralizer must process for the full manufacturer's time and rinse completely.

Surfactant types: anionic clean and lather best, cationic condition, amphoteric are mild (baby shampoos), and nonionic act as thickeners and emulsifiers.

Acid-balanced shampoo (pH 4.5-5.5) helps close the cuticle and preserve color, while alkaline shampoo swells the cuticle and accelerates color fading.

Hard water contains calcium and magnesium, which reduce lather and can leave mineral deposits; soft water lathers more readily.

Scalp massage movements are effleurage (gliding), petrissage (kneading), tapotement (tapping), and friction (circular rubbing).

Antidandruff shampoos may contain zinc pyrithione, selenium sulfide, or ketoconazole; dandruff is associated with Malassezia yeast.

Conditioners deposit cationic ingredients and humectants on negatively charged, damaged hair; protein conditioners temporarily fill gaps in the cuticle.

Shampooing and massage are contraindicated on scalps with abrasions, open sores, ringworm, lice, or scabies; the client is referred.

Wet hair is weaker and stretches, so detangling proceeds from the ends upward with a wide-tooth comb.

Standard facial sequence: cleanse, analyze, exfoliate, soften with steam, extract if appropriate, massage, mask, moisturize, and protect with SPF.

Skin types are normal, dry, oily, and combination; the Fitzpatrick I-VI scale describes UV response rather than skin type.

Facial massage movements are effleurage, petrissage, tapotement, vibration, and friction.

Extractions are limited to closed comedones softened with steam; inflamed pustules, cysts, and moles are not extracted.

Contraindications include contagious conditions (impetigo, cold sores, conjunctivitis), open lesions, and severe inflammation, all of which require referral.

AHA (glycolic, lactic) and BHA (salicylic) exfoliate by dissolving intercellular cement and increase sun sensitivity, so sunscreen is required afterward.

A magnifying lamp reveals pore size, texture, and pigmentation; a Wood's lamp uses UV light to show conditions beneath the skin surface.

Steam is timed and directed so it does not condense on the face, and eye covers shield the client from vapor and product.

Nail structures include the plate, bed, matrix, lunula, cuticle, eponychium, hyponychium, sidewalls, free edge, and mantle.

The matrix produces the nail plate, so injury there causes ridges or permanent deformity of the growing nail.

Cuticle nippers are used only on hangnails; the cuticle seal is pushed back rather than removed, and living tissue is never cut.

Nail shapes are square, squoval, round, oval, and pointed, and should mirror the natural free edge and the client's needs.

Polish is applied as base coat, two thin color coats, and top coat; thin layers dry faster and wear longer.

Methyl methacrylate (MMA) monomer is banned in most states for severe allergic reactions and nail damage; ethyl methacrylate (EMA) is the accepted substitute.

Paronychia (bacterial) and tinea unguium (fungal) are contraindications for nail service and require medical referral.

Porous files, buffers, and wooden sticks are discarded after one client; metal implements are cleaned and disinfected.

Fingernails grow about 1/8 inch per month, and toenails grow more slowly.

Hair has three layers: cuticle (overlapping scales), cortex (melanin, strength, elasticity), and medulla (central core, often absent in fine hair).

The follicle contains the bulb, papilla (nourishment), matrix (cell production), sebaceous gland, and arrector pili muscle.

Growth cycles are anagen (2-7 years, active), catagen (weeks, transition), telogen (about 3 months, resting), and exogen (shedding).

Melanin types are eumelanin (brown-black) and pheomelanin (red-yellow); gray hair results from lost melanin production in the follicle.

Hair disorders include monilethrix (beaded hair), trichorrhexis nodosa (knotted breakage), fragilitas crinium (split ends), hypertrichosis (excess growth), and hirsuties (male-pattern excess growth in women).

Skin layers are the epidermis (stratum corneum, granulosum, spinosum, basale), dermis, and subcutaneous layer.

Sebaceous glands secrete sebum and sudoriferous glands secrete sweat; both are associated with the hair follicle.

Contagious conditions such as tinea, pediculosis, and scabies require refusal of service and referral, since cosmetologists cannot diagnose or treat disease.

OSHA enforces the Bloodborne Pathogens Standard and Hazard Communication Standard (SDS access) and requires offering hepatitis B vaccination to at-risk employees.

The FDA regulates cosmetics and color additives, the EPA registers disinfectants, and state boards license practitioners and define scope of practice.

A Safety Data Sheet contains 16 sections and must be accessible for every chemical product in the salon.

Client records document service dates, formulations, patch tests, and adverse reactions, and are retained per state requirements.

Ethical duties include client confidentiality, informed consent, no diagnosis or treatment of disease, and remaining within scope of practice.

Booth rental pays a fixed fee to the salon, while commission pays a percentage of service revenue; the classification affects taxes and insurance.

Liability insurance covers claims of injury or negligence during services and is separate from premises coverage.

Advertising must be truthful; claiming to cure disease or guaranteeing results outside scope violates most state rules.