Hair coloring involves treating hair with chemical compounds to change its color. Ancient peoples used plant dyes but modern dyes are synthetic. There are temporary, semi-permanent, and permanent hair dyes. Temporary dyes wash out in one shampoo while semi-permanent dyes last 6-8 washes. Permanent dyes use oxidation to chemically bond color into the hair shaft. Bleaches lighten hair by destroying melanin using oxidizing agents like hydrogen peroxide. Proper formulation ensures dyes and bleaches do not damage hair.

1. HAIR COLORING
Presented By:
Mahewash Sana A. Pathan

2. Introduction:
• Hair coloring or hair dyeing is the practice of changing the hair color.
• Main reasons for this are cosmetic, to cover gray or white hair, to alter hair to
create a specific look, to restore the original color after it has been discolored by
hairdressing processes or sun bleaching.
• Diodorus Siculus, a Gr. Historian described in detailed how Celtic people dyed
their hair blonde.
• Dyeing of hair is an ancient art that involves treatment of hair with various
chemical compounds.
• In ancient times, dyes obtained from plants, henna, indigo, cassia obovata,
senna, turmeric, amla, black walnut, red ochre, & leeks etc.
• In 1661 book Eighteen Books of Secrets of Art & Nature, various methods of
coloring Hair black, gold, green, red, yellow & white are explained.
• Development of synthetic dyes is traced to the 1860’s discovery of the reactivity
of paraphenylenediamine (PPD) with hair.
• Eugene Schueller, the founder of L'Oréal, is recognized for creating the first
synthetic hair dye in 1907.

3. • An ideal hair dye should have following characteristics:
1. Should not be toxic to skin or hair & should not impair the natural gloss &
texture of hair.
2. Should not be dermatitic sensitizer.
3. Color that imparts to the hair must be stable to air, light, water &
shampoo.
4. Should be easy to apply.
• Important factors to be considered while selecting a dye are its molecular
size & its pH.

4. Types of hair dyes:
1.Temporary colorants
1.Semi-permanent colorants
1.Permanent colorants
1.Lighteners or bleaches

5. Temporary colorants
• They impart color to hair for a short time.
• Washed off during the first shampoo.
• Early examples are rinsing hair with either vinegar or lemon juice after shampooing with soap.
Soap which remains on hair has dulling effect & rinse was considered to give effect as result of
neutralizing the alkali. Same effect is obtained when rinsed with citric or tartaric acid.
• Powder products are simple mixture of dyestuff with citric or tartaric acid in a sachet or capsule.
To use, contents of package is dissolved in about half a pint of warm water & solution poured over
the wet hair immediately after shampooing.
• Absorption of dyestuff takes place from solution to the hair cuticle but no penetration to the
cortex or medulla.
• Various shades can be created like blue, pink, light golden or auburn shades.
• These preparations can be applied in transparent polymeric materials as sprays.
• May also be formulated with soaps, shampoos, & waxes & used as crayons for temporary
coloring.
• In shampoo type formulation, 0.5-2% of dyestuff can be incorporated depending upon color
effect required.
• pH of the solution preparation is adjusted at about 5.

6. Crayon
Color 6 gm
Srearic acid 14 gm
Triethanolamine 7 gm
Glycerol monostearte 4 gm
Beeswax 42 gm
Paraffin wax 9 gm
Microcrystalline wax 9 gm
Coconut diethanolamine 7 gm
Perfume q.s.

7. Rinse solution
Acid dyestuff 6 gm
Alcohol 10 gm
Acetic acid 10 gm
Water 74 gm

8. Semi-permanent colorants
• Color can withstand 6-8 subsequent shampoos although some of the color
is removed during each shampoo.
• Made up of dyes having smaller molecules which penetrate hair easily.
• These are mainly based on basic dyestuff of nitro-amino dyes.
• Most imp nitro dyes are picramic acid (2,4-dinitro-6-aminophenol) & 4-
nitro-1-2-phenylene diamine.
• These dyes are usually red or yellow.
• To achieve the optimum dyeing effect following must be considered-
a) Water solubility
b) The composition of vehicle or base
c) Effect of the medium
d) Effect of diluting solvents on the dye & basic composition

9. • In several cases, a mixture of an anionic & non ionic surfactant with a
cation active dye is used to get a semi-permanent coloring by forming
anion-cation color complexes.
• Color complexes can be formed by any of the following processes:
1. Mixing an anionic surfactant with solution of basic dyestuff
2. Mixing a cationic surfactant with solution of an anionic dye stuff.
3. Mixing an anionic surfactant with a solution of dyestuff containing a
cationic SAA.
• These preparations are applied to dry hair after shampooing & kept
for 30 min to allow maximum absorption, finally rinsed with water.

10. Quaternary ammonium compound 12 gm
Anionic surfactant 9.6 gm
Lactic acid 4.8 gm
Alkyloamide 12 gm
Dyestuff 1.2 gm
Water 60.4 gm

11. Permanent colorant
• These are generally accompanied by a chemical process.
• These colorants can be used to intensify the natural color or completely change the hair
color.
• These are either of vegetable origin or salts of heavy metals. But most preferred or of
commercial importance are the oxidation dye based on synthetic organic chemicals.
• Oxidation dyes such as p-phenylene diamine, p-toluene-diamine are used as permanent
dyes. They are first converted to quinine diamine which is colorless & small in size. They
penetrate the hair & form molecules of increasing size & color. These polymers are
difficult to remove & the dyes remain permanent.
• Phenols such as resorcinol, pyrogallol may be used to modify shades.
• Main ingredients of formulation will be of-
a) Base: emulsion, gel, powder, shampoo
b) Dye: oxidation base
c) Alkali: ammonia
d) Antioxidants: ammonium thioglycolate.

12. 1. Vegetable dyes
• Most imp vegetable dye is henna. It contains dried leaves of Lawsonia
alba, L. spinosa & L. inermis.
• Lawsone (2-hydroxy-1,4-napthaquinone), the main ingredient is
soluble in hot water & in a pH of 5.5 act as an effective dye.
• Powdered henna is made into paste with hot water, suitably acidified
& applied on head, kept for required time.
• Henna has no local or systemic toxicity & shows no sensitization.
• Apart from its use as dye, henna may be used in rinses.
• Addition of pyrogallol & metallic salts may be used to produce a range
of colours with henna. But this may prove toxic if applied on broken
skin.

13. Henna rinse
Henna leaves (coarsely ground) 10 gm
Alcohol 44 gm
Water 45.75 gm
Perfume 0.25 gm
Leaves are boiled in water & then
mixture is allowed to stand for a few
hours. It is strained to remove the leaves
& alcohol & perfume is added.

14. • Chamomile- contain flowers of
Anthemis nobilis & Matricania
chamomillae.
• Active ingredient is 1,3,4-
trihydroxyflavone or apigenin.
• Flower heads are applied in the
form of a paste in hot water along
with kaolin.
• It may also be used as hair
brightening rinses.

15. 2. Metallic hair dyes:
• Colours used by metallic compounds such as lead acetate are either due to sulphides
formed by sulphur in the keratin or due to metallic oxide formed by reduction.
• Hair shaft is coated with dull, metallic sheen, leaving the hair brittle.
(a) Lead dyes:
• Generally based on solution of lead acetate & it is considered that reducing action of
keratin forms insoluble lead salts.
• Coloration process is slow.
• Rate of colouring depends on conc. of lead & influenced by air & light.
• Lead acetate is normally used in combination with precipitated sulphur or sodium
thiosulphate.
Precipitated sulpher 1.3 gm
Lead acetate 1.6 gm
Glycerine 9.6 gm
Water 87.5 gm

16. (b) Bismuth dyes:
• Produce a range of colours from blond to dark chestnut.
Bismuth citrate 50 gm
Water 50 gm
Sodium thiosulphate 6 gm
Water 94 gm
Ammonium hydroxide q.s.

17. (c) Silver dyes:
• Hair is first treated with an aqueous ammoniacal solution of silver nitrate.
• After a short while, solution of pyrogallol is applied.
• Proportion of silver may be reduced for lighter shades.
• Greenish black colour is produced, which stains skin too.
Lead acetate 0.5 gm
Sodium thiosulphate 1.5 gm
Glycerine 8 gm
Alcohol 10 gm
Water 80 gm
Perfume q. s.

18. Oxidation hair dyes:
• Based on synthetic organic chemicals like p-phenylenediamine & p-
toluenediamine.
• Principle of dyeing is to add necessary oxidation end product, an
azine dye, which reacts with keratin to form insoluble azine derivative
& consequently gives a permanent colouration.
• Modifiers are used to improve stability of dye, they are resorcinol,
pyrocatechol, chlorohydroquinone, pyrogallic acid, diamino-anisidine,
etc.

19. Lighteners or bleaches:
• These are decoloring preparations because they lighten or remove the
natural color.
• Colour of the hair is due to melanin which is produced in living cells of
matrix of follicle & then distributed in the dead keratinized cortex & cuticle.
• Bleaching process is modification or lightening by destruction of the
melanin by some chemical reactions.
• This can be done by treating with oxidizing agents like alkaline hydrogen
peroxide, permanganate solutions, etc.
• After bleaching, normally the hair is rinsed with blue solution to give it a
better appearance.
• During oxidation, sulphur linkages of the hair get damaged.
• Extent of damage is dependent on the time of exposure of the hair to the
bleaching agent.

20. • Temporary coloring of hair is in demand, this is done preferably after
bleaching the hair & making the colour light, so that any shades of
colour can be imparted easily.
• Dyes, particularly lighter shade, can be applied better on bleached
hair than darker hair.
• Care should be taken not to damage the hair shaft while treating with
alkali solution.
• Treatment with alkali for longer time makes the hair soft & gelatinous
when wet & makes the combing difficult.
• To prevent damage to hair several workers suggested addition of
additives, like proteins, which can be incorporated into the bleaching
preparations or penetrated before bleaching.

21. Materials for bleaching:
• Permanganate solution is recommended for bleaching but application can
cause serious damage to the hair if any mistake is made in application.
• Alkaline hydrogen peroxide solution is preferred.
• For domestic use, 3-4% peroxide solution is suggested. Professional
application 5-6% solution can be used for faster bleaching.
• Suitable stabilizing agents, such as acetanilide, dilute acids, ammonium
bisulphate, are added in hydrogen peroxide solution.
• Presence of metals can damage the hair, sequestering agents, EDTA may be
added .
• Cholesterol, lanolin derivatives, fatty alcohols or other hair conditioning
agents are added for better appearance of hair.
• Before application, ammonia is added for faster degradation of peroxide &
bleaching effect. This also softens the hair.

22. • Products are marketed in powder, paste, & solution forms.
• Powder preparations contain inert materials such as kaolin, mag.
Carbonate mixed with peroxide & ammonia to achieve better control in
application to hair.
Ammonium bicarbonate 20 gm
Ammonium bisulphate 10 gm
light magnesium carbonate 50 gm
Light calcium carbonate 20 gm
The powder mixture is to be mixed with hydrogen peroxide solution before
use.

23. • Liquid & paste bleaches are marketed in two containers, one
containing stabilized hydrogen peroxide solution & other the
activator. Before use they are mixed in 1 part of activator & 4 parts of
H2O2 solution.
A. Carbopol 934 2 gm
hydrogen peroxide solution 88 gm
B. triethanolamine solution 10 gm
Disperse the Carbopol in peroxide with vigorous stirring. Allow to stand
for 20 min. then add solution of triethanolamine & adjust pH to 5.5.

24. HAIR DYE REMOVERS
• One method of removal can be using hot vegetable oil.
• Vegetable oil is applied to cover the hair properly, strands of hair are passed through a
heated iron marcel or comb & then rubbed with towel. Vegetable extract dyes & lead
dyes are removed by this technique.
• Turkey red oil can be used to remove dyes & is also advantageous as some other
additives can also be incorporated to help in removal of colours.
• Oxidation dyes can be removed by treating with reducing agents such as sodium
thiosulphate, sod. formaldehyde sulphoxylate, sod. dithionate solution, in conc. of 5%.
• Hydrogen peroxide solution 5-6% useful for removing lighter shades of oxidation dyes
but not for darker shades.
• Following formulation used to remove silver colour.
sodium thiosulphate 5 gm
sulphuric acid 2 gm
water 93 gm