Hair color steps

Hair Dyes Removal

 Sometimes it becomes necessary to remove hair dye:

 Due to a poor color result.

 Due to the incompatibility of one dye with another chemical hair process.

 Removal of hair dye depends upon the type of coloring process used.

 Temporary hair dyes: are removed with one shampooing.

 Semipermanent hair dyes: the amount of time for a dye to wash out is equal to the time required for the dye to color the hair shaft.

 For example, if it takes 20 minutes for a semipermanent dye to penetrate from the cuticle to the cortex, then it will also take 20 minutes for the dye to exit the hair shaft. Thus, if the hair is shampooed for 5 minutes, the dye will be removed in four shampooings for a total elapsed time of 20 minutes.

 Demipermanent and Permanent hair dyes: It is actually easier to bleach hair than to remove these unnatural pigments.

 Gradual hair dyes

 Should not be removed with peroxide as the hair can become darkened or discolored.

 It is recommended that the dyed hair is trimmed away and replaced with new growth before attempting to remove the metallic dye.

Hair Color Lightening and Bleaching

 It is the lightening of the natural hair shade.

Benefits of Lightening and Bleaching

 To give hair a lighter look.

 To prepare it for the application of a dye preparation, generally yielding a shade lighter or more vivid than the natural one.

Types of Hair color lightening

1. One-Step Hair Lightening

 Dyeing and lightening procedures are performed as one step, but the hair cannot be strongly lightened.

 Hydrogen peroxide used in the oxidation dyeing process is used to lighten the existing hair color.

2. Two-Steps Hair Lightening (Bleaching)

 First hair is bleached, then hair is dyed with the new color since hair completely stripped of color has an undesirable grayish appearance.

 This technique is used when patients wish to dye their hair more than 3 levels lighter than their hair color or if the hair contains more than 60% gray and darkening the hair color would be difficult.

Types of bleaching agents

 Hydrogen peroxide: delivered as a 6% or 9% solution expressed in volumes. It reacts very slowly.

 Ammoniated Hydrogen peroxide: ammonia fasten the reaction of the peroxide to give rapid effect.

 Persulfates : are often used in bleaching powders that give strong bleaching.

Types of lightening and bleaching products

 There are a variety of products available. To distinguish their technical or esthetic uses, they are classified as follows:

1. Hydrogen peroxide solutions and emulsions

2. Lightening and bleaching creams

3. Bleaching powders or pastes

4. Bleaching oils or gels

1. Hydrogen peroxide solutions and emulsions

 Simple aqueous delivered as a 6% or 9% solutions expressed in volumes. It reacts very slowly.

 According to the hydrogen peroxide volume, these mixtures enable one to obtain 1–3 tones lightening within 20 min.

It is useless to try to extend the reaction time, because after 20 min the partially decomposed hydrogen peroxide has no further effect.

2. Lightening and bleaching creams

 These creams generally contain ammonia and sometimes other alkaline agents such as monoethanolamine.

 Just before use, they should be mixed with a quantity of hydrogen peroxide emulsion (20–30 vol.).

 The cream form can be applied locally with more success.

 The lightening is effective because evaporation of the ammonia is slowed down.

3. Bleaching powders or pastes Used when strong bleaching is to be obtained within a short time (40–60 min), especially if the hair is dark to begin with (from chestnut to black).

 They are ranked as bleaching products as they are capable of lightening by 4 or 5 tones.

 These powders contain persulfates to give higher oxidation power.

 The powders are mixed just before use with the amount of hydrogen peroxide needed to obtain a paste.

 Application of pastes is easy because it doesn’t run easily, and the results are usually highly satisfactory.

Their disadvantage is that they dry on the scalp during the waiting period (about 1 hr), and sometimes create a sensation that the skin is tightening.

4. Bleaching oils or gels

 They are usually mixed with a quantity of as hydrogen peroxide (20–30 vol.)emulsion to produce a transparent gel.

 When mixed with hydrogen peroxide (20 vol.), the hair can only be lightened 2–4 tones as with creams. To obtain high-strength bleaching, more Hydrogen peroxide is added or two or three sachets of a reinforcing powder.

 There are many advantages to using a gel formulation:

Easy localized application.

 They are transparent; it is easy to follow the progress of the color lightening without removing the gel from the hair.

 Better than pastes in that they do not dry the scalp dry and tight.

General considerations while using bleaching agents

 Bleaching must be performed on dry hair to localize the application and allow the formation of lipid layer which protects the scalp against the risk of irritation.

 Bleaching the areas that have been previously bleached increase the damage to the hair.

 Keep in mind that the part of the hair near the root bleaches more easily than the shaft and ends. This is why, in first-time bleaching, the application must be done in two steps: the ends first and then the roots. In this way the final result will be homogeneous.

 Bleaching products should be applied with brush applicator.

 It is not advantageous to accelerate their reaction by increasing the quantity of ammonia, the volume of hydrogen peroxide, or the proportion of bleaching powders, to limit modification in hair keratin and to avoid producing any dermatitis of the scalp.

Minimizing Hair Dyes Damage

• Do not attempt to lighten or darken hair by more than three shades.

• If possible, always dye hair darker not lighter. Bleaching is more damaging than dyeing.

• Minimize the exposure of the hair to dyes by prolonging the interval between dyeing sessions.

• If both permanent waving and permanent dyeing are to be performed, the hair should be permanently waved first and permanently dyed second. Allow 10 days between permanent dyeing and permanent straightening procedures.

Caring for colored hair

• To help customers keep their hair color vibrant for as long as possible, and to protect the already weakened hair, they should be informed to:

Use the most appropriate application technique when recoloring.

 Covering visible regrowth only requires the hair dye to be used on the hair roots. This will protect the bulk of the hair from unnecessary exposure and overprocessing.

 Minimize shampooing to prolong the life of the hair dye

 Use a shampoo and conditioner specifically developed for colored hair.

 Sun exposure should be minimized because UV radiation has a direct impact on color fading.

 Don’t wash freshly colored hair too frequently. water exposure is the biggest contributor to color fading (also called wash fading).

Hair Colorants Safety

• The majority of allergic reactions to hair dyes are classified as delayed hypersensitivity or type IV reactions (ex: scalp pruritus and erythema).

• Consumers should read and follow the usage instructions of hair colorants carefully.

• For permanent and most semi - permanent hair colorants, consumers are advised to conduct sensitivity test 48 hours before each hair coloring, by following the recommendations of each product.

• It is recommended to perform the sensitivity test on the inside of the elbow.

• In case of a skin reaction at the test site, consumers should not color their hair.

• When consumers experience initial signs of an adverse reaction at the scalp during the hair coloring session, the hair dye should be rinsed off immediately.

• Hair dye inserts recommend that this test be repeated prior to each dye contact.

• Wearing protective gloves during preparation, application, and rinsing of hair colorants.

• It is possible that a patient may be allergic to one dye and not another.

• Sometimes patients with a severe para-phenylenediamine allergy, who have previously used home dyeing preparations, develop swelling and bullae  formation immediately upon application of the dye product. In their haste to come to the dermatologist’s office, they may neglect to remove all of the excess dye.