QQI Level 5 Hairdressing key terms

A small amount of colour or other chemical product applied to a tiny area of skin, usually behind the ear or in the elbow crease, and left for 48 hours to check for an allergic reaction before full application.

An immune reaction of the body to a substance that is normally harmless, showing as redness, swelling, itching or blistering, which may develop only after repeated exposure to a product.

The process by which repeated contact with a substance trains the immune system to react to it, meaning a client who never reacted before can suddenly develop an allergy to a colour or perm product.

Any condition, product history or circumstance that means a treatment should not go ahead, such as an active scalp infection, a recent allergic reaction or a hair history that makes the service unsafe.

A chemical service that must not be carried out because of something already on the hair, for example perming over a metallic or incompatible colour, or relaxing hair that has been bleached.

A confidential written or electronic record holding consultation details, products and strengths used, timings, patch test dates and results, so each visit can be built safely on the last.

The structured conversation before a service in which the stylist asks about hair history, lifestyle, health and expectations, analyses the hair, and agrees a realistic plan and price with the client.

A hands-on and visual assessment of the hair's texture, density, porosity, elasticity and condition, together with its chemical history, used to choose suitable products, strengths and timings.

How readily hair absorbs and holds moisture, judged by how quickly it wets or dries; high porosity from damage takes colour fast but loses it quickly, while low porosity resists penetration.

A check in which a wet strand is gently stretched and released; healthy hair stretches and springs back, while hair that snaps or stays stretched shows damage or loss of protein structure.

A small test cutting or section of hair treated with the actual product and strength planned, timed to check the result and development rate before the full service begins.

A scale from 0 to 14 measuring acidity and alkalinity, with 7 neutral; hair and skin sit around pH 4.5 to 5.5, and products above this swell the cuticle and lift it open.

A shampoo formulated close to the natural pH of hair and scalp, so it cleans gently without excessive cuticle swelling and helps smooth and close the cuticle after washing.

The tough outer layer of overlapping scales that protects the hair shaft; when it lies flat hair looks shiny and resists chemicals, and when raised hair feels rough and absorbs products quickly.

The thick middle layer of the hair shaft, made of protein chains and containing the melanin that gives hair its colour; chemical and physical changes to colour and shape happen here.

The natural pigment produced in the hair follicle that gives hair its colour; the two types, eumelanin for brown-black and pheomelanin for red-yellow, combine to create every natural shade.

A strong chemical link between protein chains in the cortex that holds hair in its shape; perming and relaxing break these bonds and then reform them in a new position.

The warmth or depth of colour that remains in the hair after natural or artificial pigment is removed, which shows through and influences the final result of a colour or lightening service.

The process of removing natural or artificial pigment from the hair using a lightening product, revealing warmer underlying tones as the colour is lifted through the levels.

A hydrogen peroxide solution mixed with colour or bleach to open the cuticle, develop the colour and lift pigment; its strength, measured in percentage or volume, controls the amount of lift.

The chemical reaction in which oxygen from the developer combines with colour molecules or melanin, making colour molecules larger so they stay in the hair or breaking pigment down to lighten it.

Applying a gentle, low-lift colour after lightening to neutralise unwanted warmth or add a fashion shade, giving a cleaner and more controlled final result.

A circular chart of primary, secondary and tertiary colours used to predict results and choose a shade that neutralises an unwanted tone, working with the colour opposite on the wheel.

The chemical in a perm lotion that breaks the disulphide bonds in the cortex so the hair can be wound and reshaped around a rod into a new curl pattern.

The second chemical applied in a perm or relaxer service, which rebuilds the disulphide bonds in their new position and locks the shape in place before the hair is rinsed and styled.

The timed period a chemical product is left on the hair to complete its reaction, counted from the end of application and kept within the manufacturer's guidance to avoid damage or under-processing.

The angle at which hair is held away from the head during cutting; it controls the amount of graduation or layering, from flat at 0 degrees to 90 degrees and beyond for layers.

Dividing the hair into clean, controlled subsections using clips and partings so a cut, colour or perm is applied evenly and the result is balanced and predictable.

The first cut section of hair that sets the length and shape all following sections are matched to, keeping a haircut balanced and consistent across the head.

A cutting technique in which hair is cut at an angle so lengths build up in layers, creating weight, volume and a stacked shape at the perimeter of the haircut.

A texturising technique in which the tips of the scissors are used to snip into the ends of a section, softening the line and removing bulk without shortening the overall length.

A cut made with zero elevation and a straight cutting line across the section, producing a solid, even perimeter with maximum weight and a strong, clean finish.

Drying and shaping damp hair with a hand-held dryer and brush, using tension, direction and heat to smooth the cuticle, build volume or create a bend in the hair.

A product applied to hair before using heated tools, forming a barrier that reduces moisture loss and heat damage, and allowing straighteners, tongs and dryers to be used safely.

A product applied after shampooing to smooth the cuticle, replace moisture and reduce friction, making hair easier to comb and improving shine and manageability.

A controlled manipulation of the scalp with the fingertips during shampooing or treatment, improving circulation, relaxing the client and helping to lift product and debris from the scalp.

The transfer of bacteria, fungi or viruses from one person, tool or surface to another, which in the salon is controlled by cleaning, disinfection, sterilisation and correct waste handling.

A process that reduces the number of harmful micro-organisms on tools and surfaces to a safe level, using an approved chemical at the correct strength and contact time after cleaning.

A process that destroys all micro-organisms, including spores, on reusable tools, usually achieved with an autoclave and required for items that may contact broken skin or blood.

The routine measures taken with every client, such as hand washing, gloves, correct tool hygiene and safe waste disposal, on the assumption that any person may carry infection.

Items worn to protect the stylist and client from harm during work, including gloves for colour and chemicals, a gown or cape, and appropriate footwear and eye protection.

The framework of risk assessment, safe storage, labelling, ventilation and training that salons must apply to chemicals such as colour, bleach, perms and aerosols to protect everyone.

The document supplied with a chemical product that lists its hazards, first-aid measures, safe handling, storage and disposal, and which must be available to staff in the salon.

A written review of what in the salon could cause harm, who might be affected and what controls are needed, reviewed regularly and updated when products, equipment or staff change.

The written guidance supplied with a product or tool covering correct mixing, strength, timing, storage, aftercare and safety warnings, which must be followed to achieve safe, predictable results.

Arranging the workstation, chair height, client position and own posture so work is carried out comfortably and without strain, reducing the risk of repetitive injury to the stylist.

The legal duty to collect, store and share client personal and treatment information securely and only for the purpose it was given, keeping records confidential and accessible only to those who need them.

A style in which long hair is gathered, pinned and secured above the shoulders, built from a prepared base with sections, backcombing and pins to hold shape and balance.

Teasing sections of hair towards the scalp with a comb to create volume and a firm base for upstyling, which must be handled gently to avoid tangling and cuticle damage.

Winding wet or damp hair on rollers, pins or clips and drying it into a shape so that curls and volume last, forming the base for comb-outs and long-hair styles.

Recommending and selling take-home products to clients based on their diagnosed hair and scalp needs, supporting the salon's income and helping clients maintain results between visits.

The ongoing process of updating skills and knowledge through training, qualifications, reflection on feedback and keeping up with new products and techniques throughout a career.

Reviewing your own work and experiences honestly, identifying what went well and what to improve, and using that insight to plan the next steps in your learning.

A recorded programme of learning activities, courses, reading and peer review that keeps a stylist's competence current and can be shown to employers and professional bodies.

A supervised placement in a real salon where a learner practises salon routines, client care and technical skills under guidance, building confidence, evidence and employability.

Giving full attention to a client, noting words, tone and body language, and confirming understanding by summarising back, so the agreed service truly matches what the client wants.