DC Esthetician key terms

The process of significantly reducing the number of disease-causing microorganisms on surfaces and tools by cleaning and applying an EPA-registered disinfectant. It is the minimum standard for implements that contact intact skin.

The use of an EPA-registered hospital-grade product to destroy most pathogenic organisms on nonporous implements and surfaces. Items must be cleaned first, then fully immersed or wiped per label contact time.

The complete destruction of all microbial life, including bacterial spores, usually achieved with an autoclave using steam under pressure. It is required for items that may contact broken skin or blood.

An infection-control approach in which all blood, body fluids, and non-intact skin are treated as potentially infectious regardless of a client's known health status. It drives glove use, handwashing, and safe handling of sharps.

A standardized document supplied with a chemical product that lists its hazards, safe handling, first-aid measures, and storage requirements. Estheticians must keep SDS sheets accessible for every product in the salon.

A condition, medication, or circumstance that makes a treatment inadvisable or unsafe for a client. Examples include active infection, recent isotretinoin use, or open lesions; identifying them protects both client and practitioner.

The outermost, avascular layer of the skin, composed of keratinocytes in progressive stages of maturation. Its barrier function and turnover rate determine how quickly clients see results from exfoliation and topical products.

The outermost sublayer of the epidermis, made of flattened, keratin-filled cells embedded in a lipid matrix. This brick-and-mortar structure controls water loss and limits penetration of topical ingredients.

The dominant cell type of the epidermis, produced in the basal layer and progressively keratinized as it migrates outward. Its life cycle underlies desquamation, pigmentation transfer, and wound healing.

A pigment-producing cell located in the basal layer that transfers melanin to surrounding keratinocytes through melanosomes. Its activity explains variations in skin color and the risk of post-inflammatory hyperpigmentation after treatments.

The skin's ability to retain water and exclude irritants, allergens, and microbes, chiefly through the stratum corneum and its lipids. Compromised barrier function shows as redness, tightness, and sensitivity.

The measurement of water vapor escaping through the epidermis, used as an indicator of barrier integrity. Elevated values suggest dehydration or barrier damage and guide product and treatment choices.

The time it takes for cells to travel from the basal layer to shedding at the surface, typically about 28 days in young adults and slower with age. It determines how quickly exfoliation and retinoid results appear.

A six-category classification of skin phototypes based on response to ultraviolet exposure and tendency to burn or tan. It guides laser settings, waxing precautions, and sun-protection counseling.

Darkened patches that develop after inflammation or injury to the skin, more common in deeper skin tones. Aggressive extractions, waxing, and peels can trigger it, so technique and client selection matter.

A client's baseline classification, usually described as normal, dry, oily, or combination, based on oil production and hydration. It differs from skin condition, which is temporary and treatable.

A reactive state marked by stinging, redness, or tightness in response to products or environmental triggers. It is managed with fragrance-free formulas, patch testing, and a strengthened barrier.

The removal of comedones and sebum using gloved fingers wrapped in tissue or a comedone extractor after softening the skin. Correct pressure and hygiene prevent scarring and post-inflammatory pigmentation.

A plugged follicle, either open (blackhead) where oxidized sebum darkens the surface or closed (whitehead) where the pore stays covered. Identifying the type determines whether extraction or chemical exfoliation is appropriate.

A gliding, stroking massage movement performed with light to moderate pressure, usually toward the heart. It warms tissue, aids product absorption, and begins and ends most facial massage routines.

A kneading and lifting massage movement that compresses muscle and soft tissue. On the face it is applied gently to cheeks and jaw to relieve tension without dragging delicate skin.

A brisk, rhythmic percussion movement using fingertips or the edges of the hands. On the face it is used briefly and lightly to stimulate circulation and tone, avoiding bony areas and sensitive skin.

The ordered sequence of cleansing, analysis, exfoliation, extractions, massage, mask, and finishing products used in a service. Following a consistent protocol supports safety, timing, and predictable outcomes.

The active growth stage of the hair follicle, when the hair is anchored deeply and grows continuously. Because the bulb is well supplied, anagen hairs respond best to waxing and laser treatment.

The resting stage of the hair cycle, ending in shedding of the hair. Telogen hairs are held shallowly and may release easily during waxing, which is why regrowth schedules matter.

The repeating sequence of growth, transition, and rest that every follicle follows independently. Understanding it explains why hair removal must be repeated at intervals to catch hairs in the right phase.

A resin-based wax applied warm and removed without a strip once it sets. It grips shorter hairs and is often preferred for sensitive areas such as the face and bikini line.

A thin, sticky wax applied in the direction of hair growth and removed with a fabric strip against the growth. It is efficient for large areas like legs but requires careful temperature control.

Reinserting a used applicator into a wax pot after it has touched a client's skin. It is prohibited in most jurisdictions because it can transfer blood-borne pathogens between clients.

A logarithmic measure from 0 to 14 of hydrogen ion concentration, where lower values are acidic. Skin's acid mantle sits near pH 4.5 to 5.5, and product pH affects exfoliation strength and barrier comfort.

The slightly acidic film of sebum, sweat, and lipids on the skin surface that discourages pathogens and supports barrier enzymes. Alkaline cleansers can disrupt it temporarily, leaving skin tight and vulnerable.

A water-soluble acid such as glycolic or lactic acid that loosens dead cells by breaking intercellular bonds. Concentration and pH determine strength, and sun protection is required after use.

A lipid-soluble acid, chiefly salicylic acid, that penetrates pores to exfoliate inside the follicle. It suits oily and acne-prone skin but is avoided in clients allergic to aspirin.

A stable blend of water and oil held together by an emulsifier, forming the base of most lotions and creams. Understanding emulsions helps predict texture, absorption, and how to layer products.

An ingredient such as glycerin or hyaluronic acid that attracts and holds water in the skin. It hydrates but needs an occlusive layer on top to prevent water loss in dry climates.

An ingredient that forms a film on the skin surface to slow water loss, such as petrolatum or dimethicone. It is used to seal in hydration and support a compromised barrier.

An oily substance produced by sebaceous glands that lubricates skin and hair and contributes to the acid mantle. Excess sebum combined with dead cells contributes to comedone formation.

The study of how hues relate and neutralize one another, applied in makeup to correct discoloration. Green cancels redness, while peach or orange softens blue-toned dark circles.

Selecting a base whose undertone and depth blend seamlessly with the client's jawline and neck. Testing on the jaw in natural light prevents the visible line and mismatched undertone common in wrong shades.

A pigmented product used to hide blemishes, redness, or under-eye darkness after foundation. Correcting shades are applied first, then a skin-matching shade is layered on top.