OH Cosmetology cheat sheet

Disinfectant efficacy tiers: hospital disinfectant kills most bacteria plus some viruses and fungi; tuberculocidal products also destroy the organism that causes tuberculosis; sterilants (used on nonporous items) destroy all microorganisms including spores.

Order of operations for implements: wash with soap and warm water, dry thoroughly, then fully immerse in an EPA-registered disinfectant for the contact time printed on the label. Solution that is dirty, diluted, or past its contact time does not disinfect.

Spore-forming bacteria (bacilli) survive ordinary disinfectants, and porous items that cannot be immersed - emery boards, cotton, wooden sticks, neck strips - cannot be disinfected and must be discarded after one use.

The pH scale runs 0 to 14, with 7 neutral, below 7 acidic, and above 7 alkaline; each whole number represents a tenfold change in hydrogen ion concentration. Skin and hair sit near pH 4.5 to 5.5.

Hair shaft layers: cuticle (overlapping transparent scales that protect the interior), cortex (about 80 percent of the mass, holds melanin and the disulfide bonds), medulla (innermost core, sometimes absent in fine hair).

Hair growth cycle: anagen (active growth, roughly two to six years, about 90 percent of scalp hair), catagen (transition, a few weeks), telogen (resting phase of about three months ending in shedding).

Skin layers: epidermis (avascular outer layer; keratinocytes mature upward, melanocytes sit in the basal layer), dermis (nerves, vessels, glands, follicles), subcutaneous (fat for insulation and shock absorption).

Cranial nerves to know: the fifth (trigeminal) is the chief sensory nerve of the face and also supplies the muscles of chewing; the seventh (facial) is the motor nerve for the muscles of facial expression.

Chemistry of shape change: alkaline products swell the cuticle and soften keratin; thioglycolate reduces disulfide bonds at about pH 9 to 9.5, hydroxide relaxers break the same bonds at very high pH, and the bonds re-form in the new shape.

Haircolor levels run from 1 (black) to 10 (lightest blonde). In a color formula the number before the slash is the level and the number after the slash is the tone.

Hydrogen peroxide developer strengths: 10 volume = 3 percent, 20 volume = 6 percent, 30 volume = 9 percent, 40 volume = 12 percent. Developer strength plus processing time determines how many levels of lift occur.

Color wheel: primaries are blue, red, and yellow; secondaries are orange, green, and violet; complementary pairs (blue/orange, red/green, yellow/violet) neutralize each other and control unwanted tone.

Sodium hydroxide relaxers break disulfide bonds at a pH near 12 to 14; ammonium thioglycolate permanent waves work near pH 9 to 9.5 and must be neutralized with hydrogen peroxide or sodium bromate to rebuild the bonds.

Client hair analysis: porosity (how quickly hair absorbs and releases moisture), elasticity (a wet strand stretches and returns), density (hairs per square inch), and texture (coarse, medium, or fine diameter).

Cutting elevation controls shape: 0 degrees produces a blunt, one-length form; 45 degrees graduates; 90 degrees creates uniform layers; 180 degrees creates long layers.

Thinning shears remove bulk and add mobility; they are used from mid-shaft to ends, not at the scalp line, and are avoided on fine or fragile hair where they cause weak spots.

Heat styling safety: hair loses strength when wet, and thermal tools on dripping hair can boil moisture inside the shaft and fracture it, so blow-dry to roughly 80 percent dry before using irons or pressing combs.

Standard facial sequence: cleanse, skin analysis, exfoliate, tone, massage, mask, moisturize, and finish with sun protection.

Massage movements: effleurage (light gliding strokes), petrissage (kneading and lifting), tapotement (rapid tapping), and vibration or rolling; strokes follow muscle direction and generally move upward and outward.

Epidermis layers from deepest to surface: germinativum (basal), spinosum, granulosum, lucidum (palms and soles only), and corneum - the corneum is what exfoliation removes.

Skin types are normal, dry, oily, combination, and sensitive; the T-zone (forehead, nose, chin) is typically oilier, and product selection follows the observed type rather than the client's preference.

Fitzpatrick scale types I through VI describe burning and tanning response: type I always burns and never tans, while type VI rarely burns; peel and light-treatment parameters are adjusted by type.

Waxing rules: hair should be one-quarter to one-half inch long, wax is applied in the direction of growth and removed against it, and wax is never applied over inflamed, broken, sunburned, or freshly peeled skin.

Common contraindications requiring postponement or referral: isotretinoin use, recent chemical peel or dermabrasion, open lesions, active infection, sunburn, and pregnancy for certain electrical treatments.

Sun protection: SPF rates UVB protection (SPF 30 blocks about 97 percent of UVB), broad-spectrum or PA labeling indicates UVA coverage, and protection is reapplied about every two hours and after water or heavy sweating.

Nail structures: plate (visible body), bed (skin beneath the plate), matrix (growth area), lunula (visible half-moon of the matrix), eponychium (cuticle), hyponychium (seal under the free edge), and sidewalls.

Fingernails grow about one-eighth inch (roughly 3 mm) per month; toenails grow more slowly, growth speeds up in warm weather, and longer digits grow faster than shorter ones.

The nail plate is compacted keratin and contains no nerves or blood supply, so trimming is painless; the matrix, bed, and sidewalls are living tissue that can bleed or become infected if over-filed.

Filing technique for natural nails: use a fine-grit file and stroke in one direction from sidewall toward the tip; sawing back and forth peels the plate edges and causes splitting.

Porous items such as emery boards, wooden pushers, cotton, and toe separators used on skin are single-use; metal implements are washed, dried, and immersed in an EPA-registered hospital disinfectant after every client.

Condition versus disease: onychorrhexis (splitting), leukonychia (white spots), Beau's lines, and hangnails are conditions a manicurist may see, while onychomycosis (fungal) and paronychia (bacterial) are diseases that require referral to a physician.

Pedicure sequence: soak with a sanitizing product, trim and file, push back cuticles, exfoliate, massage, then polish; basins, files, and implements are disinfected between clients.

Polish application: thin base coat, two thin color coats, then top coat, sealing across the free edge; thick coats wrinkle, stay tacky, and dry unevenly.

Markup percentage = (retail price minus product cost) divided by product cost, times 100; retail price = cost times (1 + markup rate).

Gross profit = revenue minus cost of goods sold; net profit = gross profit minus operating expenses such as rent, wages, utilities, and supplies.

Break-even units = fixed costs divided by (price per service minus variable cost per service); the result is the minimum number of services needed to cover overhead.

Average ticket = total revenue divided by number of tickets; retail-to-service ratio = retail sales divided by service sales.

Client retention rate = returning clients divided by total clients, times 100; rebooking rate is the share of clients who schedule the next appointment before leaving.

Commission pay = service revenue times commission rate; booth renters instead pay a fixed weekly or monthly fee and keep the remaining revenue.

Inventory turnover = cost of goods sold divided by average inventory; slow turnover ties up cash in stock that can expire or go out of style.

OSHA requires a Safety Data Sheet for every chemical product in the salon, employee training under the bloodborne pathogens standard, and documentation of exposure incidents.

Ohio regulates the industry through the Ohio State Cosmetology and Barber Board, which licenses individuals (cosmetologist, esthetician, manicurist, hair designer, natural hair stylist, barber, instructor) and licenses salons and shops.

Ohio training hour requirements include 1,500 hours for cosmetologist licensure, 600 hours for esthetician licensure, and 200 hours for manicurist licensure.

A salon operates under a managing cosmetologist who is responsible for the shop's day-to-day compliance, and both the salon license and each practitioner's license must be current and available for inspection.

Implements are cleaned with soap and water and then completely immersed in an EPA-registered hospital-grade disinfectant for the labeled contact time after each client; the solution is changed as the label directs.

Porous single-use items - emery boards, wooden pushers, cotton, neck strips - are discarded after one client, and products are removed from containers with a spatula rather than fingers to prevent contamination.

Services may not be performed on skin or nails that are broken, inflamed, sunburned, or show signs of infection or a contagious disease; the client must be referred to a physician.

Board inspectors may enter a licensed salon during business hours without an appointment to check sanitation, licensing, and records, and violations may result in citations, fines, or license discipline.

An expired or lapsed license may not be used to perform services; practicing without a current license, or allowing an unlicensed person to perform services, is grounds for discipline.