Esthetician (South Korea National Technical Qualifications in Barbering and Beauty) key terms

The lowest level of infection control: cleaning and reducing the number of microorganisms on surfaces, tools and hands using soap, detergent or approved sanitizing agents. It precedes disinfection and does not destroy all pathogens.

Use of EPA-registered chemical disinfectants on nonporous implements and surfaces to destroy most pathogenic bacteria, fungi and some viruses, but not bacterial spores. Implements must be cleaned first, then fully immersed for the label's stated contact time.

The highest level of infection control, destroying all microbial life including bacterial spores, typically by autoclave steam under pressure, dry heat or chemical sterilants. It is required for implements that penetrate skin or contact blood.

A U.S. federal regulation requiring employers to protect workers from blood and other potentially infectious materials through an exposure control plan, hepatitis B vaccination offer, personal protective equipment, labeling and post-exposure follow-up.

A standardized sixteen-section document from a product manufacturer listing a chemical's hazards, ingredients, handling, storage, first-aid and disposal instructions. Estheticians must keep one available for every professional product used in the salon.

The slightly acidic film, roughly pH 4.5 to 5.5, of sebum, sweat and skin lipids on the surface that inhibits bacteria and supports barrier function. Alkaline cleansers and soaps disrupt it temporarily.

An oily substance produced by sebaceous glands and secreted through hair follicles that lubricates skin and hair and helps retain water. Excess sebum contributes to comedones and acne in oily skin.

The outermost layer of the epidermis, composed of flattened, keratin-filled dead cells held in a lipid matrix. It provides the primary barrier against water loss, chemicals and microorganisms.

A cell in the basal layer of the epidermis that produces melanin pigment and transfers it to surrounding keratinocytes. Melanocyte activity determines skin color and increases with ultraviolet exposure.

A pore plugged by sebum and dead keratin cells. Open comedones (blackheads) darken at the surface through oxidation; closed comedones (whiteheads) are covered by skin and may become inflamed.

A network of vessels, nodes and organs that collects excess tissue fluid, filters it and returns it to the bloodstream while supporting immune defense. Manual drainage strokes follow its direction toward lymph nodes.

A tiny smooth muscle attached to each hair follicle that contracts with cold or emotion, raising the hair and creating goose bumps. Contraction also helps push sebum out of the gland.

A six-category classification of skin phototypes based on color and response to ultraviolet exposure. Estheticians use it to predict sunburn and pigmentation risk and to guide treatment intensity.

A condition, medication or circumstance that makes a treatment unsafe or inadvisable, such as active infection, recent isotretinoin use or open lesions. Contraindications are identified during consultation and documented in the client record.

A filtered ultraviolet lamp used in a darkened room to examine the skin surface. Different conditions fluoresce distinct colors, helping assess dehydration, pigmentation, bacterial presence and oiliness.

A document completed before service that records health history, medications, allergies, prior treatments and contact details. It provides the practical and legal basis for safe treatment decisions and later follow-up.

A largely hereditary classification based on oil production and water content, usually described as normal, dry, oily or combination. Skin type is distinct from skin conditions such as dehydration, sensitivity or acne.

A gliding massage stroke performed with palms and fingers, following lymph flow toward the nodes. It warms tissue, relaxes the client and links other movements within a facial routine.

A kneading, lifting or rolling massage movement that compresses muscle and soft tissue. On the face it is applied lightly with fingertips to stimulate circulation and relieve tension without dragging the skin.

Mechanical removal of a plugged pore using gentle pressure or a sterile extractor after softening the skin. Only non-inflamed comedones are extracted; inflamed lesions and deep cysts must never be squeezed.

The active growth stage of the hair cycle, when the follicle is anchored to the bulb and produces new hair. Waxing is most effective in this phase because the hair is firmly rooted.

A stripless wax that shrinks and grips the hair as it cools, then is lifted away without cloth strips. It is applied thicker and is preferred for coarse or sensitive areas such as the face and bikini.

Inflammation or infection of hair follicles appearing as red, tender bumps, sometimes with pus. It can follow waxing or shaving and is a contraindication for further hair removal until it resolves.

Inserting a wax applicator back into the pot after it has touched a client's skin. The practice transfers microorganisms and is prohibited; single-use applicators are discarded after each application.

Fine, short, lightly pigmented hair covering most of the body. It is not the target of body waxing; terminal hair, which is longer, coarser and darker, responds best to wax.

The study of how colors relate and neutralize one another on the color wheel. Makeup artists apply complementary colors to correct unwanted tones, for example green to cancel redness and orange to cancel blue.

Selecting a foundation whose undertone, depth and finish blend with the client's skin, tested along the jawline in natural light and allowed to set before judging the result.

The fast-curing main ingredient in most lash extension glues, which polymerizes on contact with moisture. Sensitization and allergic reaction are real risks, so patch testing and ventilation are essential.

Measuring brow shape with facial landmarks, typically the inner corner, the arch above the outer iris and the tail at the outer corner, to create balanced brows before waxing, tinting or styling.

A water-soluble acid such as glycolic, lactic or mandelic acid that loosens bonds between dead cells in the stratum corneum. Its concentration and pH together determine exfoliating strength.

The percentage of an acid peel solution that remains unbuffered and chemically active. Along with pH, it largely determines exfoliation depth, so both values must be known before selecting a peel.

Applying a basic solution to stop an acid peel at the planned endpoint and restore skin pH. Not every peel needs it; self-neutralizing acids such as glycolic rely on timed removal and dilution.

An alternating electrical current delivered through a glass electrode filled with neon or argon, producing ozone and warming the skin. It is used for mild acne and circulation in professional facials.

A direct electrical current with positive and negative poles. The negative pole repels moisture and softens sebum, while the positive pole tightens tissue and is used in disincrustation and iontophoresis.

Mechanical exfoliation that projects fine crystals or a diamond tip against the skin while a vacuum removes dead cells. It smooths texture and is usually performed as a series with careful pressure control.

A lens and light combination mounted on an adjustable arm that enlarges the skin surface during analysis and extractions. Correct positioning and frequent cleaning of the lens are essential.

The legally defined procedures and responsibilities an esthetician is licensed to perform. Working outside it, such as diagnosing disease or performing medical treatments, risks license loss and personal liability.

The client's voluntary agreement to a treatment after being told its benefits, risks, alternatives and expected outcome. Documented consent protects both the client and the practitioner if a dispute arises.

Designing body position, tools and workspace to reduce strain during repetitive work. For estheticians this means adjusting bed height, keeping wrists neutral and taking breaks to prevent musculoskeletal injury.

The amount added to a product's wholesale cost to set its retail price, often expressed as a multiple. A common salon retail markup ranges from two to three times the cost.

The principles guiding honest, respectful and fair conduct with clients, colleagues and employers, including confidentiality, informed consent, avoiding exaggerated claims and disclosing conflicts of interest.