PA Cosmetology cheat sheet

Hair shaft layers: cuticle (outer overlapping scales that protect the cortex), cortex (middle layer, roughly 80–90% of hair mass, holds melanin and all side bonds), medulla (innermost core, may be absent in fine or light hair).

Hair is about 90% protein (keratin); its elements are carbon, oxygen, hydrogen, nitrogen, and sulfur. The sulfur forms disulfide bonds, which give hair its strength.

Three side bonds: disulfide (strongest; broken by relaxers, permanent waves, and bleach), salt (broken by water plus changes in pH, re-forms as hair dries), and hydrogen (broken by water or heat, re-forms as hair cools or dries).

Growth cycle: anagen (active, 2–6 years, about 90% of scalp hair), catagen (transition, 2–3 weeks), telogen (resting and shedding, about 3 months). Average scalp growth is roughly 1/2 inch (1.25 cm) per month.

pH scale runs 0–14; hair and scalp sit near 4.5–5.5. Alkaline solutions swell the shaft and lift the cuticle; acid-balanced products (pH 4.5–5.5) smooth and close it.

Developer (hydrogen peroxide) strengths: 10 volume = 3%, 20 volume = 6%, 30 volume = 9%, 40 volume = 12%; percentage equals volume x 0.3. Higher volume produces more lift and more lightening, with more damage.

Law of color: primary colors are yellow, red, and blue; secondary colors are orange, green, and violet; complementary pairs (blue/orange, red/green, yellow/violet) neutralize each other. Hair levels run 1 (black) to 10 (lightest blonde).

Relaxer rules: sodium hydroxide (lye) relaxers run about pH 12–14; no-lye guanidine relaxers about pH 9–10. Retouch applications go on new growth only, and an acidic neutralizer (pH 4.5–5.5) stops processing and re-forms disulfide bonds.

Cold wave (perm) pH ranges: alkaline waves about 7.0–9.5 (ammonium thioglycolate), acid-balanced waves about 4.5–7.0 (glyceryl monothioglycolate, requires heat). Both break disulfide bonds; the neutralizer or oxidative agent rebuilds them in the new shape.

Skin layers: epidermis (stratum corneum, lucidum, granulosum, spinosum, basale), dermis (collagen, elastin, nerves, glands, blood vessels), and subcutaneous layer or hypodermis (fat, insulation).

Acid mantle: a slightly acidic film (pH about 4.5–5.5) of sebum, sweat, and lipids that inhibits bacteria and maintains the barrier; alkaline soaps and harsh cleansers strip it and leave skin dry and reactive.

Fitzpatrick scale I–VI grades sun reactivity: type I always burns and never tans, type VI rarely burns with deeply pigmented skin. Higher numbers mean more melanin and lower burning risk, but treatments can still cause hyperpigmentation.

Primary lesions: macule (flat color change), papule (raised, no fluid), pustule (pus-filled), vesicle (small blister), bulla (large blister), wheal (raised and itchy), nodule (deep solid mass), cyst (sac of fluid or semisolid).

Secondary lesions: crust (dried exudate or scab), scale (flaking skin), scar, excoriation (scratch mark), fissure (crack), ulcer (open crater), and atrophy (thinning).

Waxing rules: hair at least 1/4 inch (6 mm) long; patch-test first; apply the strip in the direction of hair growth and remove against growth while holding skin taut. Do not wax over broken skin, sunburn, or skin treated with retinoids or acids.

Facial massage movements: effleurage (gliding), petrissage (kneading), tapotement (tapping), vibration, and friction (small circles). Avoid massage over severe acne, boils, recent peels, or active infection.

Esthetician scope: cleanse, analyze, exfoliate, massage, apply masks, apply makeup, and remove hair. Do not diagnose or treat disease; refer suspicious, contagious, or changing lesions to a physician.

Exfoliants: AHAs (glycolic, lactic) loosen the intercellular glue of the epidermis and work on the surface; BHAs (salicylic acid) are oil-soluble and penetrate follicles. Both increase photosensitivity, so sun protection is required.

Nail unit parts: nail plate (keratinized, no nerves), nail bed (pink tissue beneath the plate), matrix (produces the plate and determines thickness and shape), lunula (white half-moon), free edge, nail folds, and nail grooves.

Cuticle versus eponychium: the cuticle is dead, non-living tissue shed onto the nail plate at its base; the eponychium is the living skin fold it comes from. Only the cuticle is softened and pushed; live tissue is never cut.

Growth: fingernails grow about 1/8 inch (0.1 mm) per month and replace in 4–6 months; toenails grow more slowly, replacing in 9–12 months. Growth is faster in summer and on the dominant hand.

Nail shapes: square (straight sides, flat free edge), squoval (square with rounded corners), oval, round, almond, and pointed. Shape is chosen to follow the natural free edge and the contour of the finger.

Filing technique: use a fine-grit file and move in one direction, from each corner toward the center. Sawing back and forth causes splitting and peeling, and coarse grits thin the plate.

Sculptured acrylic chemistry: monomer liquid (ethyl methacrylate) plus polymer powder (polymethyl methacrylate) polymerize into a hard enhancement; a dehydrator removes surface moisture and a primer improves adhesion. Methyl methacrylate (MMA) is not approved for cosmetic nail use.

Recognize and refer, never treat: onychomycosis (fungal infection), paronychia (red, swollen, pus-filled nail fold), onycholysis (plate separation), onychorrhexis (splitting), koilonychia (spoon nails), onychocryptosis (ingrown nail), onychophagy (biting).

Pedicure safety: whirlpool basins are drained, cleaned, and disinfected with an EPA-registered hospital-grade disinfectant between clients; porous items such as pumice, abrasive paddles, and foam files are single-use and discarded.

Polish sequence: base coat, two thin color coats, then top coat, capping the free edge to seal. Each color layer needs a few minutes to set before the next is applied.

Four levels of decontamination: cleaning (soap and water remove visible debris), sanitation (reduces pathogens to a safe level on surfaces and hands), disinfection (kills most bacteria, fungi, and viruses on nonporous items), sterilization (destroys all microbial life including spores). Always clean before disinfecting.

A hospital-grade disinfectant must be EPA-registered and labeled bactericidal, virucidal, and fungicidal; implements are fully immersed for the contact time on the label (commonly 10 minutes, but labels differ).

Porous items (wooden sticks, cotton, towels, emery boards, foam buffers, pumice) cannot be reliably disinfected and must be discarded after a single client or given to the client.

Blood or body-fluid exposure: stop the service, put on gloves, clean the wound with an antiseptic, bandage it, disinfect all contaminated implements and surfaces, and seal contaminated disposables in a double plastic bag.

Safety Data Sheets (SDS) list each chemical's hazards, safe handling, required PPE, and first-aid steps; OSHA's Hazard Communication Standard requires them to be accessible to all employees.

Universal precautions mean treating all blood and body fluids as infectious; handwashing with soap and water is required before and after every client and after removing gloves.

Electrical safety: keep cords and appliances away from water, never immerse a plugged-in tool, use GFCI outlets, unplug before cleaning, and remove frayed or damaged cords from service immediately.

Housekeeping: keep floors dry and post signage for spills, store chemicals below eye level in labeled original containers, keep food and drink away from chemicals, and never mix products such as chlorine and ammonia, which release toxic gas.

Disinfectants are for surfaces and implements only, never for skin or as hand sanitizer.

The Pennsylvania State Board of Cosmetology sits within the Department of State's Bureau of Professional and Occupational Affairs; it licenses cosmetologists, estheticians, nail technicians, natural hair braiders, and teachers, and its rules appear in 49 Pa. Code Chapter 63.

Two separate credentials are required: the individual practitioner license and the salon (shop) license for the facility. Licenses are not transferable and must be produced on request of a Board inspector.

Each licensee's current license must be posted conspicuously at the workstation or in the salon, and the salon license must be displayed in the shop.

Board inspectors may enter and inspect a licensed salon during business hours without advance notice; refusing entry is grounds for disciplinary action.

Discipline available to the Board includes reprimand, suspension, revocation, refusal to renew, civil penalties, and orders for remedial training for violations such as unsanitary practice or unlicensed operation.

Unlicensed practice and aiding unlicensed practice are prohibited; a salon may not employ or permit anyone without a current license to perform cosmetology services.

Facility requirements: hot and cold running water, covered waste receptacles, closed cabinets for clean supplies, adequate lighting and ventilation, and a designated area for mixing and dispensing chemicals.

Licensees may not diagnose or treat a disease; a client with a suspected contagious or infectious condition must be refused service and referred to a physician.

Licenses are renewed biennially; performing services on an expired or lapsed license is treated as unlicensed practice.