Bleaching/blonding

Bleaching of natural hair color can be done as a single cosmetic application but is also part of oxidative hair coloring. Bleaching, blonding, and lightening of human... 

If lighter colors than these are desired it is necessary to decolorize all the melanin in the hair in a preliminary step, and then add color back to the desired depth in a second treatment. This is known as a double-process treatment. The decolorization step consists of treating the hair with an alkaline mixture of persulfate salts and peroxide. The persulfate is added to the peroxide as a dry powder immediately before applying to the hair. Although the persulfate salts alone do not have any bleaching effect, the persulfate—peroxide mixture can remove all the melanin in the hair. Dark brown or darker hair can be lightened to a light blonde shade in about an hour. 

After the hair is bleached it has an uimatural straw-like color and is then dyed to the desired tone with either a semipermanent or a permanent hair color product. The dye products designed to color bleached hair to a natural looking blonde shade are called toners. 

In hair coloring a light ash blond shade may require as Httie as 0.5—1% of intermediates, whereas a tme black may require up to about 5%. In principle, the formulator blends precursors that yield red, blue, and yellow dyes. The base in which the components are dissolved or suspended is similar to that used in simple bleaches and may include alkanolamides, various types of surfactants, thickening agents, and solvents. Removal of undesirable dyes is achieved by treating the discolored hair with a powerful reductant of the sulfite family. 

Blond A silk bobbin lace originally the color of raw sUk or blond hair, but now usually bleached white or dyed black. 

Blonding agents. Ammonium persulphate. Use to booster the oxidative effect of hydrogen peroxide in hair-bleaching procedures. May induce type-IV and type-I allergies. Clinical symptoms include contact urticaria, dermatitis, rhinitis and asthma. Cross reacts with potassium persulphate. 

Table 8 Polymer Uptake GPC/RI Method Blond Bleached Hair 0.1% Solution, 22°C...

When a commercial hair bleaching mixture is applied to brown hair, the hair turns blond. Has a chemical reaction occurred Explain your answer. 

Diluted H2O2 (between 3% and 8%) is used to bleach human hair when mixed with ammonium hydroxide, hence the phrase "peroxide blonde". 

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