AR Barber cheat sheet

The hair shaft has three layers: cuticle (outer protective scales), cortex (middle, holds pigment and gives strength), and medulla (inner core, may be absent in fine hair).

pH scale runs 0-14; 7 is neutral, below 7 acidic, above 7 alkaline. Hair and skin are naturally acidic at about pH 4.5-5.5.

The three growth phases are anagen (active growth), catagen (transition), and telogen (resting/shedding).

Electrolysis-type chemical reactions: an oxidizing agent adds oxygen or removes hydrogen; a reducing agent adds hydrogen or removes oxygen.

Sodium hydroxide, thioglycolate, and ammonium thioglycolate are alkaline; hydrogen peroxide is acidic and acts as an oxidizer.

The hair's cortex contains hydrogen, salt, and disulfide bonds; water breaks hydrogen bonds, and disulfide bonds are broken by chemical relaxers.

Melanin comes in two forms: eumelanin (brown/black) and pheomelanin (red/blonde).

The resting skin surface pH favors bacteria; alkaline soaps raise pH and can strip the acid mantle.

Bacteria shapes: cocci (round), bacilli (rod), spirilla (spiral).

Pathogenic bacteria cause disease; nonpathogenic bacteria are harmless or beneficial.

A disinfectant kills most microorganisms on hard, nonporous surfaces; an antiseptic is applied to skin.

Sterilization destroys all microbial life, including spores, and is required for items that pierce skin.

Bloodborne pathogens include HBV, HCV, and HIV; they spread through blood and body fluids.

Standard precautions treat all blood and body fluids as infectious.

A Material Safety Data Sheet (SDS) describes chemical hazards, handling, and first aid.

Single-use items (razor blades, cotton, wooden sticks) must be discarded after one client.

Implements must be cleaned, then immersed in an EPA-registered hospital-grade disinfectant for the label contact time.

Hair texture is classified as fine, medium, or coarse; density is the number of hairs per square inch.

Porosity describes the hair's ability to absorb moisture: low porosity resists, high porosity absorbs quickly.

Elasticity is the hair's ability to stretch and return; normal hair stretches up to 50% of its length.

Hair types: straight, wavy, curly, and tightly coiled; curl pattern relates to the shape of the follicle.

Scalp conditions: pityriasis (dandruff), seborrheic dermatitis (oily, yellowish scales), and tinea (fungal ringworm).

Sebum from sebaceous glands lubricates hair and scalp; overproduction causes oily scalp.

Treatments: moisturizing conditioners for dry hair, protein treatments for damaged hair, medicated shampoo for dandruff.

A patch test is performed before applying color or chemicals to check for allergic reaction.

Sectioning: divide hair into four sections (top, sides, back, nape) to control the cut.

Elevation (lifting) determines the angle of the cut; 0 degrees is a blunt/one-length cut, 90 degrees is a uniform layer, 180 degrees is long layers.

A blunt cut creates a solid line at one length; a graduated cut builds weight at the perimeter.

Clipper guards: smaller numbers cut closer to the scalp; larger numbers leave more length.

Razor shaving: hold the razor at about a 30-degree angle; stretch skin taut and shave with the grain.

Beard design uses the jawline, cheek line, and neckline as reference points; the neckline sits above the Adam's apple.

Cross-check by combing hair in the opposite direction to verify even length.

Texturizing shears remove bulk without changing the overall length.

Hair color levels run 1 (black) to 10 (lightest blonde); the developer (hydrogen peroxide) lifts natural pigment and deposits color.

Volume strengths: 10 volume (3%) deposits only, 20 volume (6%) lifts 1-2 levels, 30 volume (9%) lifts 2-3 levels, 40 volume (12%) lifts 3-4 levels.

The law of color: primary colors are red, yellow, and blue; secondary colors are orange, green, and violet; complementary colors neutralize each other.

Permanent color uses aniline derivatives and requires a patch test 24-48 hours before application.

Relaxers use sodium hydroxide (lye) or ammonium thioglycolate (no-lye) to break disulfide bonds; a neutralizer reforms the bonds.

Processing time increases with coarser hair and higher porosity; always follow the manufacturer's timing.

Overprocessing causes breakage and loss of elasticity; strand tests guide chemical timing.

Color wheel: blue neutralizes orange, green neutralizes red, and violet neutralizes yellow.

The consultation identifies the client's goals, hair history, lifestyle, and any contraindications before service.

Contraindications include scalp abrasions, recent chemical services, allergies, and certain medical conditions.

A client record documents services, products used, timing, and any reactions for future reference.

Informed consent is required before chemical services; explain risks and expected outcomes.

Professional ethics include confidentiality, honesty, and maintaining a clean, safe environment.

Ergonomics: adjust chair height, keep wrists neutral, and take breaks to prevent repetitive strain.

Communication skills include active listening, open-ended questions, and confirming the plan with the client.

Refer clients to a physician for scalp diseases or conditions beyond the barber's scope.

Licensure: barbers must hold a valid state license and renew it per the state's renewal cycle.

Sanitation rules typically require disinfecting implements after each client and using single-use items.

Blood spill procedures require gloves and an EPA-registered disinfectant; follow the state's exposure control plan.

Scope of practice defines which services a licensed barber may legally perform.

Establishments must post licenses and health/safety notices as required by state law.

Continuing education hours may be required for license renewal, depending on the state.

Record-keeping: maintain client records and sanitation logs as required by the state board.

Violations may result in fines, suspension, or revocation of license.