Problem Of Losing The Colour Biology Essay

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Consumers of hair colouring products face a common problem of losing the colour after a certain period of time, which requires frequent repetitions of the colouring treatment. How can you preserve colour retention for colour-treated hair?

Coloured hairs play an important role in the world of fashion. Concept of hair colour was occurred many years ago and people were using the plant and minerals to colour the hair. Keratin, eumelanin and phaeomelanin are proteins which are responsible for colour of the hairs. Ingredients are used for preparation of the hair dye including solvent, surfactant, alkali, buffer, alcohol, conditioner, developer and dye precursor. These components impart the colour to the hairs by coating, penetrating in to the cuticle and or by depositing colour on to cortex. But dye precursors are used in the high concentration in these days which is responsible for the allergic reaction, damage of hair. To achieve long lasting effect of the permanent hair colour while reducing their side effect, henna is used in the formulation. Henna being natural colorant, has fewer side effects, moreover it is cheap and easily available. Lawsone molecule, present in henna colours the hair by binding to the hair shaft and keratin. From this study it can be concluded that the colour retention of permanent colour of coloured hair can improved by adding natural dyes such as henna and the deleterious effects of dyes can be decreased by reducing the percentage of the dye precursor para phenylene diamine.

Problem statement

Nowadays hair colour plays an important role in society. Concept of hair dye is occurs many years ago when people using plants and minerals for colouring to hair. Recently synthetic dyes are used which containing following ingredients; (1)

Table 1: Components of hair colour with its functions (5)





Dye vehicle

Water, propylene glycol


Foaming, thickening

Sodium lauryl sulphate, ceteareth-25, cocoamide MEA, oleth-5


Swell hair, bleaching

Ammonia, monoethanolamine


Stabilize, reproducible

Disodium phosphate, citric acid

Dye precursors

Impart colour

1-napthol, P- Phenylenediamine,P-aminophenol.



Cetearyl alcohol, glyceryl stearate



Cetrimonium chloride


Oxidant , bleaching

Hydrogen peroxide

Henna, black walnut shells etc natural colorants are used for colouring hair. Main disadvantage of natural colour is, the colour is not a long lasting. Natural colour gives colour by coating shaft of hair. After shampooing colour will disappears after few days. Dyes which contain synthetic ingredients such as PPD, ammonia, hydrogen peroxide etc cause allergic reactions and damage to the hair. Mechanism of permanent colour is to remove original colour of hair and in place of original colour add hair colour which is being used. (3) Permanent colour should not be easily washable by shampooing to show the long lasting effect. New growth of the hair is not affected by hair dye hence periodical reapplication of hair dye is necessary. To avoid the repetition of dye permanent hair colour is used. (2)

Summary of preferred solution

Eugene Schuler a French scientist who used hair colour commercially in 1909. He used p-phenylenediamine as a colouring agent in hair colour. At that time he established a small scale industry. After few years the name was changed to L'Oreal, one of the best hair dye industry. In 1950 approximately 7% of American women used hair dyes but today 75% of American women are colouring their hair with dyes. (7). Keratin (protein) is a main constituent of a hair, nails and skin. Hair also contains a two more proteins eumelanin and phaeomelanin which is responsible for their natural colour. Eumelanin covers black to brown hair and phaeomelanin shows golden blond, ginger, and red colours. Colouration is varying between how much percentages of amount of that protein present in hair. If this type of melanin is absent in individuals then hair shows either white or gray colour. (3)

For preparation of effective hair colour, permanent hair colour should be containing a dye for colouration and developer for the opening of a cuticle which is an outer layer of a hair. The concentration of each ingredient varies in all permanent hair dye. People choose a permanent hair dye which is best suited for their hair and complexion. Ingredients which are used in hair dyes cause side effects depends on the degree of concentration they are used.


Ingredients of commonly used hair dyes:



Most of the expensive hair colour brands such as Garnier, Pantene, Sunsilk don't use ammonia, as it may cause skin allergy, irritation and hair loss. Ammonia swells the hair and acts as a bleaching agent. Unlike hyderogen peroxide it does not act as a colour developer. Along with bleaching action it also act as conditioning agent. In our proposed formula, natural colorant henna, it shows conditioning properties.

P-Phenylene diamine (PPD) :

Most of the permanent hair dyes contain PPD because it is very effective than any other dyeing agent. But in PDD containing dye, addition of colour developer is necessary, which may cause side effects. Concentration range of PPD is very short, means it is effective in very low concentration (0.04%-0.250%).

Hydrogen peroxide:

It acts as developer or oxidising agent. Hydrogen peroxide is used to open cuticle and shows the long lasting hair colour effect. If the amount of developer is increased, then large amount of sulphur is lost from hair. Such sulphur loss causes the hardness of hair hence the concentration of developer such as hydrogen peroxide is maintained 3 - 12%.

In the cosmetic industry various types of chemicals are used to prepare hair dyes which are highly reactive. Water plays an important role in the light fastness of dyes on the fibres of the hair. Water gets diffused into hair to facilitate oxygen and cause the swelling of fibres. By the help of the thermal transformation and 310nm photo transformation we can examine what oxygen does into hair when it enters. Classification of hair dyes are depend on ingredient used and retention time of dye on hair. On this basis hair dyes are classified as follows;

Temporary dyes:

The particle size of ingredients used in these dye are large in size, which can't enter cuticle. Colour particles are adsorbed and can be easily removed by shampooing.

Semi-permanent dyes:

In semi -permanent hair dye size of particle is smaller than that of temporary dyes. The particles partially penetrate into cuticle and it will be washed out after 12 - 24 shampoos. It contains very low levels of oxidising agent and ammonia hence can be used for damaged hair.

Permanent dyes:

This colour is not completely permanent. It gets faded after several washes. It is very easy to make a dark hair into a light shade by using these dyes. First hair is lightened and then application of colour is done. (8)

Mechanism of permanent hair colour:

Cuticle is an outer layer of a hair shaft and it should be opened first before the permanent colour entered into the hair. After opening of cuticle colour reaction takes place with inner layer of the hair that is cortex and colour is bound to the cortex. In most of the cases permanent colour shows lightning of a hair followed by the deposition of a new colour. Permanent hair colour contains oxidising agent or developers such as peroxide. The role of oxidising agent is to remove existing colour by breaking the chemical bonds in hair strand. Also contain alkalising agent such as ammonia, useful for the opening of the cuticle and deposition of colour on the cortex. When oxidising agent and alkalising agent come together a chemical reaction occurs. Because of this chemical reaction cuticle gets swelled and entry of coloured pigment into the cortex takes place. (3) Melanin is present in the cortex which is being lightened and in place of original colour dye colour is obtained. Conditioners and alcohols also added in the hair colour. Aim of conditioner is to close the cuticle after completion of colouring and prevent new colour from easy wash out. Characteristic odour of hair colour is because of sulphur which is released during chemical reaction. (4)

Figure 2 Effect of natural and chemical dyes on hair (6)



Henna is natural colouring agent used for hair dyeing. Henna is scientifically called as Lawsonia inermis, commonly known as henna or red henna. The leaves of Lawsonia contain a red-orange dye pigment known as Lawsone (hennotannic acid). Chemically, the molecule of Lawsone is 2-hydroxy-1, 4-naphthoquinone.

Advantages of henna (10):

Henna acts as an Anti bacterial, anti fungal and astringent.

Henna conditions the hair.

Henna controls reoccurrence of dandruff.

Henna makes hair soft, strong, tangle free and cures split ends.

In market black henna and neutral henna are also available, but actually they do not contain henna. Black henna is obtained from a plant called Indigofera tinctoria and Neutral henna is obtained from the plant Cassia obovata.

Black henna, which is known to contain p-phenylenediamine (PPD) stains the hair black but causes allergic reactions to skins.

Henna releases dye onto the hair optimally in acidic, humid and warm environment, due to these optimal conditions colour retention time will be increased for some time. However use of lemon juice with henna can be too harsh for the scalp (12).The intensity of developed colour depends upon the natural colour of hair. If the natural colour of hair is dark then the colour developed by henna will be dark.

The original henna i.e., Lawsonia inermis shows various species having red, white, pink and yellow flowers. The plants with white flowers are used in the preparation of the dye. Cloves can be added to henna to get dark colours. Neutral henna contains a golden dye molecule that stains grey hair into yellow.

We can get other colours by using henna and mixture of other dyes or metallic salts. Henna when mixed with other plant dyes gives various colours these include (11),

Natural red: henna

Violet: indigo

Brown: henna and woad 

Golden: henna and sadr (saffron) 

Chestnut brown: henna and woad 

Dark warm brown henna: karchak and vashma 

Black henna:  karchak, vashma and indigo

How Henna Works on Hair

Diagram of Henna Dyeing Hair

Diagram of Henna Dyed Hair

Henna hair dye colour chart (9):

Henna colour

Your natural hair colour

Light blonde

Med. Blonde

Dark blonde

Light brown

Med. Brown

Dark brown


Conditioning effect

Conditioning effect

Conditioning effect

Conditioning effect

Conditioning effect

Conditioning effect


Golden auburn

Coppery aburn


Soft auburn brown

Med.auburn black

Warm coppery black


Reddish black

Reddish black

Reddish black

Ash brown

Rich ash brown

Dark ash brown

Bright red

Bright red

Med. Bright red

Rich bright red

Bright reddish brown

Bright auburn

Rich coppery brown


Rich burgundy

Med. Burgundy



Rich burgundy

Deep burgundy

Dark brown

Med. brown

Rich brown

Med. Rich brown

Warm brown

Rich coppery brown

Deep coppery brown

Light brown

Light honey brown

Honey brown

Rich honey brown

Light golden brown

Med. Golden brown

Warm coppery brown

Light red

Soft light red blonde

Light red blonde

Light natural

redlight golden brown

Conditioning effect

Conditioning effect

Medium brown

Light brown

Medium brown

Rich brown

Warm auburn

Warm brown

Rich coppery brown




Natural red

Reddish brown


Warm auburn

Catherine Cartwright-Jones's Quick Mix Chart

If your hair is:

Use Cassia

Use ½ cassia and ½ henna

Use Henna

Use 2/3 henna and 1/3 indigo

Use ½ henna and ½ indigo

Use 1/3 henna and 2/3 indigo

Use Henna first, then indigo


Glossy blonde

Strawberry blonde

Vivid red

Light brown

Medium brown

Darker brown

Black, though it make take more than one try to get complete black.

Dark Blonde

Glossy dark blonde

Coppery red

Vibrant red

Light brown

Medium brown

Darker brown; it may take more than one application to get it.

Black, it may take more than one try to get complete black.


Glossy red

Warm red

Vibrant red

Reddish brown

Medium brown

Darker brown; it may take more than one application to get it.

Black, it may take more than one try to get complete black.

Medium Brown

Glossy medium brown

Red highlights


Medium Brown

Medium brown

Dark brown


Dark Brown

Glossy dark brown

Red highlights

Dark Auburn

Dark Brown

Warm brown

Dark brown



Glossy black

Slight red highlights

Black with red shimmer

Warm Black

Warm black

Warm black




Golden copper

Coppery red

Light brown

Medium brown, though it may take more than one application to get full colour.

Dark brown, though it may take more than one application to get full colour.

Black, though it make take more than one application to get full colour

Oxidative hair dyes:

In US the oxidative hair dyes having almost 80% market shares. Oxidative dyes contain oxidizing agent (developer), ammonia as an alkalizing agent. Primary intermediates, oxidants and couplers are commonly used ingredients in the modern oxidative dyes. Some examples of the primary intermediates and couplers are as follows:

Primary intermediates: Para- Phenylenediamine (PPD) , para-toluenediamine(PTD), Para- diamine, ortho- or Para- aminophenol.

These primary intermediates are used in formulation in different proportion as 0.05% used in light shade dyes and 2.0% used in dark shade dyes.

Couplers: meta-phenylene- diamines, meta-aminophenol, resorcinol

Couplers gives a final colour shade to hair by conducting an oxidizing reaction with a primary intermediates. There is equal proportion of primary intermediates and couplers in modern

Oxidative dyes as molar ratio of 1:1.

Hydrogen peroxide and ammonia are used in the dyes preparation as oxidant and alkalinizing agent respectively. (13)

Para-phenylenediamine is the main substance which is largely used in the oxidative hair dyes. Recently Para- phenylenediamine have been experimentally observed that it is Allergen. When the PPD is used into repeatedly in 0.3%, the skin area gets accumulated and may cause dermatitis. Children are very sensitive to PPD allergy and may even need hospitalization in severe cases.

Anaphylaxis may occur in some rare cases due to allergy of para-phenylenediamine. Skin redness is also one of the adverse effect occur on the body skin. Mostly it occurs on the face, hand and chest regions of the skin. Skin irritation, skin itching, skin rashes are also occurring due to allergy of Para-phenylenediamine.

The report from the 'British medical journal' say that the allergic reactions occurring due to PPD have been increase more in young children with use of hair dyes. In 20th century the allergy due to PPD have been such a critical problem and because of that PPD was strictly banned from hair dyes in Sweden, Germany and France.

Quality control test to measure the amount of a p-phenylenediamine in the human body.

Selected assays are carried out to measure the amount of p-phenylenediamine and its metabolites present in the human body. The amount of PPD absorbed in the human body due to use of oxidative hair dyes is very important to ensure safety of the dye. Large amount of a PPD may act as carcinogens or mutagens, which have been found in the TA 1538 and TA 98 strains of salmonella typhimurium and animals.

To find out the amount of a p-phenylenediamine and its metabolites of oxidative hair dyes in human body and in rabbit biological fluid. There is a method called liquid chromatography coupled with electrochemical detector has been developed. This quantitative method calculate the 3 different derivatives as N, N'-p-phenylenebisacetamide, 4-aminoacetanilide and p-phenylenediamine in human urine and rabbit blood, urine and faeces.


In the experimental point of view eight healthy human volunteer were selected who had not used hair dyes last 6 months. And on other hand rabbits with overnight fasting were selected. 60mg PPD by the oral administration with 10 ml water had been given at the time of experiment to rabbits.

The urine sample collected at each time period at an interval of 6 hours after administration of sample. However the blood, urine and faeces were collected as prescribed time period and stored at -300C till analysed it. This rabbit samples were centrifuged at 2000g for 30 min, and makes it deproteinized with same procedure.

After finishing with the sampling, the experiment carried out with the use of liquid chromatography; where the standard solutions, stock solutions are prepared from methanol-deionised water (1:1 v/v) with 1 * 10-2mol/L of oxidative dyes. The lichrospher RP- select B analytical column were use. The detection has been carried out with use of an ultraviolet detector set at 240 and 256nm. The electrochemical detector used at +1.0V.

Result and conclusion:

By the graphs and calculating values of percentages amount of a p-phenylenediamine, we come to the conclusion that the method described to calculate p-phenylenediamine and its metabolites offers good analytical results and selective for such measurements in human body. The marketed hair dyes contains PPD maximum up to 2% concentration, which has been proved to be safe for human use and may not cause carcinogenic or mutagenic symptoms.

1. Journal of Photochemistry and Photobiology A: Chemistry 147 (2002) 225-231

Short communication

Photochemical and thermal modifications of permanent hair dyes

Laurence Motz-Schalck, Jacques Lemaireâˆ-

Laboratoire de Photochimie Moléculaire et Macromoléculaire, Université Blaise Pascal, UMR CNRS 6505, F-63177 Aubière Cedex, France

Received 17 July 2001; received in revised form 18 October 2001; accepted 23 October 2001

2. Journal of Dermatological Science

Review article

Targeting to the hair follicles: Current status and potential

Hanna Wosicka a, Krzysztof Cal b,*

a Department of Pharmaceutical Technology, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland

b Department of Pharmaceutical Technology, Medical University of Gdansk, Hallera 107, 80-416 Gdansk, Poland

3. cited on 18 april 2010

4. The World of HYPERLINK ""HairHYPERLINK "" HYPERLINK ""ColourHYPERLINK ""‎ - Page 112

John Gray - Health HYPERLINK ""Health+&+Fitness""&HYPERLINK ""Health+&+Fitness"" Fitness - 2005 - 121 pages

5. cited 28april

6. on 25 april

7. cited on 21 april






13 Safety assessment of personal care products/cosmetics and their ingredients

Gerhard J. Nohynek a Eric Antignac a, Thomas Re b, H

erve Toutain a

a L'OREAL R&D, Global Safety Evaluation, 92600 Asnières, France

There are many alternatives which are in the market but they have many adverse effects.


Kool-aid drink mix is a homemade dying but it is less effective. It doesn't provide lustre, sleek look to hair and it's a temporary dying.

Side effects: 

->Unpleasant smell and gritty texture.

    ->Uneven fading of dye after several number of shampooing.

   -> It gives best look for one day. And we need to apply again for even colour. 



Walnut and water is also used for dying but it provides only brown colour. This is also a temporary natural colorant and it doesn't act as a conditioner.

   Side effects:

   ->It contains a toxic chemical called jugione which causes skin irritation and even skin cancer when applied to hair. 


Lead acetate, hydrogen peroxide, propylene glycol, ammonia when used imparts dark colors.

Side effects:

-> This requires frequent dying for colour. Due to frequent dying lead acetate reacts with protein and form lead sulphide which is potentially toxic (lead poisoning).

->Damages the hair.

->Disrupts heart activity.

->Clots blood.

->Reduces intelligence.

->Neurological problems. Disrupt the function of brain neurotransmitter.

->Effects sensory and motor development.

->As it crosses the placenta in pregnant women it causes foetal mortality.

 The European Union banned lead acetate because cosmetic manufacturer could not prove it as a safer one.

It was even banned by Canada because there was suspicion that it is carcinogenic and reproductive toxic


This came into account in 1900's

~Coal tar, hydrogen peroxide when used imparts only black colour.

Side effects:

-> This has many allergic reactions and causes bladder cancer.

->Skin rash, irritation, swelling or redness.

->Hair follicle irritation, swelling or redness.

->Staining of skin.

The FDA states that coal tar contains approximately 10,000 different chemicals, of which only about 50% have been identified. The composition of coal tar varies with its origin and type of coal. According to the International Agency for Research on Cancer, preparations which has more than 5 percent of crude coal tar are Group 1 carcinogen.


~Azorubine, hydrogen peroxide when used imparts red to maroon colour to hair.

Side effects: This has adverse effects such as skin swelling.

->Skin rashes.

->Breathing problem if you're exposed for a while or for the first time.

->Causes bad reaction in asthmatic.

Banned in US, Sweden, Norway.

~Allura red and hydrogen peroxide when used imparts dark red colour. Allura red can be easily absorbed into the cuticle with less amount of hydrogen peroxide but allura red has adverse effects such as decreasing the IQ level.

FD&C red: 40.It was found that not safe due to conflicting test results which are connected to cancer.

It was banned in Germany, Switzerland, Norway, Belgium, Sweden, and Austria.

7) P-Phenylenediamine:

The Recent hair dye contains following ingredients p-phenylenediamine, ammonia, hydrogen peroxide, eugenol.

 Side effects of PPD:

->Cause Asthma:

Long-term exposure to dye sensitizes the airways and this cause asthma.

A number of studies confirmed that hair stylist have asthma when compared to other population because they are more exposed to the dye.

->Development of cancer: 

Cancer is caused due to combination of several factors damaging the DNA cells. Many studies have been conducted to try to determine whether long-term hair dye use causes cancer, and it is controversial subject

->.Most studies have focused on possible increased risk of bladder cancer. Some studies have found that women who had continuously used  had higher levels of risk..Recent studies says that it causes non-Hodgkin's diseases, lymphoma, multiple myeloma and leukaemia It is found that Hair stylist has more cancer levels than other.

->.Allergic and Skin Reactions

PPD is a skin sensitizer, meaning that it can stimulate the immune system to cause a variety of allergic reactions. The skin may become red, blister, itch and burn on exposure of PPD. Allergic reactions may also cause breathing difficulties and can even be fatal.

->Severe effects from drinking PPD

Severe lung problems and deaths have been reported after accidental ingestion of PPD. Hair dyes should always be kept out children's reach to prevent accidents.

Henna comes from pure dried plant that contains red orange dye molecule and act as slight acidic mix where as Indigo is a plant with dark blue dye molecule which act as slightly basic mix. If you apply henna on to grey hair it give coppery red colour where as the mixture of henna ,indigo gives brunette colour. If you apply henna initially and after rinsing you apply with indigo it imparts black colour. These colours are permanent.

Studies raise some questions about the safety of hair dyes, but at this point there's no basis for us to say that hair dyes pose a definitive risk allergy to the skin, irritation to eye or may lead to cancer

In the final analysis, consumers will need to consider the lack of demonstrated safety when they choose to use hair dyes.

In a previous investigation performed in hairdressing salons in Sweden, the contents of hair dye compounds in 22 hair dye mixtures were analysed and found to contain 0.004-0.250% PPD but today standard hair dye formulations marketed in industrialized countries today contain a maximum of 2% PPD mixed with hydrogen peroxide (3-12)