L3 Technical Diploma Colour and Lighten

​Dermatitis is an industry-related disease. The condition affects the epidermal layer of the skin. When colouring or lightening hair, you must always wear non-latex gloves when handling colour or chemicals associated with colouring. This includes when:​

• you are mixing and measuring colour and lightener​

• you are applying colour and lightener​

• you are removing colouring and lightening products.

​Use the client’s previous service details to identify any problems or limiting factors that may have been identified. If the previous service indicates an allergic reaction to a colouring service, you will need to re-test with an alternative product. If the client suffers from psoriasis or eczema you will need to discuss alternative services or follow medical advice from a GP.

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  Test​	When​	How​	Why​	Consequence​
  Skin test​ ​	24–48 hours before any colouring service ​	Clean the area before applying the colour behind an ear or in the crease of the elbow. Apply as per manufacturer’s instructions.​	Paraphenylenediamine (PPD) in hair colouring can cause allergic reactions. ​	If a positive reaction occurs, you cannot proceed. PPD reactions can cause skin breaking, dermatitis, permanent scarring of the skin, internal irritation or anaphylactic shock. DO NOT colour.​

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  Incompatibility test​ ​

  Before the lightening or colour service.​

  Take a cutting of hair and place it in a bowl with 20 parts peroxide to 1 part perm lotion. Wait 30 minutes. ​

  Tests for metallic salts. These are present in certain home hair colours, older houses with copper piping or houses with their own water supply. If there is a positive reaction, the hair may fizz, bubble or turn a khaki/flat colour and the bowl may feel hot. ​

  Carrying out the service if metallic salts are present may result in structural damage to the hair and disintegration.​ DO NOT proceed.​

• Elasticity test​ ​

  Before any service on wet hair to test the tensile strength of the cortex. ​

  Spray a few strands of hair to wet it, then gently stretch the hair. ​

  If the hair stretches and does not return to its original length, the hair has poor elasticity. ​

  You may cause structural damage to the hair. If the hair breaks you will not achieve the desired result. Apply a conditioning treatment.  ​

• Colour test/test cutting ​ ​ ​

  Before a colouring or lightening service to determine if the desired result can be obtained.​

  This can be carried out on the head, but it is easier to take a cutting of the hair and apply the chosen colour or lightening product to it.​

  This determines whether the hair can reach the target shade, whether it is an entirely new colour or a colour correction.​

  The desired outcome may not be achieved.​

• Colour development strand test ​ ​ ​

  During the colouring or lightening service.​

  Remove a little of the developing colour or product and check the development.​

  Use a dampened piece of cotton wool and wipe away a small section of colour or product.​

  Permanent colour has a timed development, but bleach can take any time at all, so constant checking is vital to achieve the target shade or prevent disintegration of the hair.​

• Porosity test​ ​

  Before the lightening or colouring service on dry hair.​

  Run your fingers along a few strands of hair to feel for any roughness.​

  Absorption of  liquid. Hair in good condition will have a smooth cuticle. Cuticle scales that feel rough and raised are  porous.​

  You may cause structural damage to the hair, resulting in  breakage and uneven colour.​ Apply a porosity leveller.​