History of hair colouring reviewed

As this was often repeated by one of the founder’s sons (Bruce Gelb) it seemed a good practice to adopt and so this terminology will be used throughout this series of articles. Most articles concerning the history of hair colouring will start with a phase of the general type “hair colouring can be traced back some 4,000 years or so”. This is most likely true but it is best to start this article with a warning about sources of information especially with the growth of the use of the internet for research. Much information found through simple internet searching is derivative (i.e. is gleaned from other sources) and many pieces of information can often be traced back to a single, possibly incorrect source. It is always advisable to check back to the original source and to make an assessment of the likely accuracy of that source. It should also be remembered that not everything that was written on paper before the advent of the internet was accurate – there was just less of it. The sources used in this article have been referenced as far as possible and perhaps the best place to start for an in-depth discussion of the history of hair colouring (as seen in 1972) is the chapter by Florence Wall in the book edited by Sagarin & Balsam.1 This book is also a source of a large number of additional references going back as far as, for example, Pliny the Elder who died during a slightly too close observation of the eruption of Mount Vesuvius. Pliny was a great observer and collector of natural phenomena and is a source of other earlier “technologies” gleaned perhaps from both the Greeks and Egyptians. Pliny lived at the height of the Western Roman Empire which ended in the 5th Century. The history of cosmetics, including hair colouring, in Byzantine times has been reviewed by Lascaratos et al.7 This covers the period AD 324 to 1453 and represents the continuation of the Roman Empire in the East after the fall of the Western Empire. The study of Byzantine sources is particularly useful as it represents a continuation of Greek knowledge and probably much that was lost after the fall of the Western Roman Empire. Until the middle of the 19th Century, the story of hair colouring is dominated by the use of “natural” materials – both plant and metal derived. A more recent (if shorter) review of hair colouring history was given by Zviak2 in the 1st edition of The science of hair care which was somewhat shortened in the 2nd edition.3 Charles Zviak, who is now deceased, was a former chairman and chief executive of L’Oréal. L’Oréal was founded by young chemical engineer called Eugène Schueller in Paris who started by making hair colouring products in his flat during the night in 1907.4 Schueller’s first product was called Aureole (the French word for halo) and he called his first company “Societe Francaise des Teintures Inoffensives pour Cheveux” (The French Harmless Hair Dye Company) which later was altered to L’Oréal. The development of synthetic organic chemistry during the 19th Century was applied in the area of fur, feather and hair colouring and this along with the discovery of oxidising agents such as hydrogen peroxide altered the technology of hair colouring products considerably. A good discussion of the state of understanding of hair colouring technology in 1929 can be found in the book by Redgrove and Foan.5 This book is a collaboration between Stanley Redgrove (a cosmetic chemist, alchemist and philosopher) and Gilbert Foan (a hairdresser). In 1929 many types of chemical mixtures were being used to colour the hair and a number of “new technologies” were emerging. The question of the toxicology of hair dyes and the safety of hair colouring products was discussed quite widely in this book. Stanley Redgrove appears to be a very interesting if neglected character in the history of the development of cosmetics. In 1931 Lawrence Gelb left America with his young family to look for new products to sell as he had lost much in the financial crash of 1929.6 He discovered a company called Mury in Paris which was selling a hair colouring product called Clairol. Lawrence Gelb and his wife Joan brought back $200 worth of the products to sell in New York and subsequently developed Clairol to a point where in 1959 it was acquired by Bristol-Myers. In 2001, Clairol was bought by Procter & Gamble. The history of hair colouring in the early 20th Century and the establishment of companies selling products for “professional” use are inevitably linked to the foundation of the modern multinational companies. Since about 1950 the development of products and brands for home use by the consumer dominates the history of hair colouring products. Today, the marketing of hair colouring products globally is dominated by a few very large companies but this does not stop many others trying to enter the business.

Plant-derived materials
The early history of hair colouring products is based on the use of “naturally occurring” materials – either those obtained from plants or those containing metals – in a wide variety of mixtures which were sometimes startling. Perhaps one of the first colorants (for either skin or hair) was made from henna leaves – powders made from these have been found in Egyptian tombs. The first recorded user of henna as a hair colorant is claimed to be Queen Ses, the mother of King Teta of the third dynasty. The henna plant is a shrub known botanically as Lawsonia inermis and has been widely used for an unknown length of time in many areas from the Egypt through the Middle East to Asia. Powdered henna is usually made up into a paste with water just before use and then applied to the hair. It produces a somewhat variable red/orange shade which is retained quite well on the hair having a high affinity for keratin. The active ingredient in henna is thought to be lawsone (2-hydroxy-1, 4-naphthoquinone) which in the plant is bound to glucosidic residues. In order to produce different, darker shades indigo has been used as a hair colouring material sometimes in combination with henna. The main source of indigo is Indigofera argenta which was cultivated from early times in Persia (Iran) and the dried and powdered leaves are known as “reng”. Indigo is also found in the leaves of Isatis tinctoria or woad claimed to have been used by the ancient Britons to colour themselves. A large number of other plant-based materials (e.g. camomile, catechu, madder, logwood and quercitron to name but a few) have been used in attempts to colour the hair but there is insufficient space to go into detail in this article. In general, these materials do not perform very well when compared with modern synthetically derived dyes and they generally suffer from a lack of stability both in the product and on the hair. Two final “natural” materials are, however, worth mentioning and these are nutgalls and the walnut as these provide a link with the first commercially available products at the start of the 20th Century. Nutgalls are caused to form on the branches and leaves of the white oak tree (Quercus infectoria or lusitanica) by the penetration of the tissue by a parasitic wasp. These little excrescences contain tannins, gallic acid and pyrogallol (1, 2, 3-trihydroxybenzene). This material forms the basis of a hair colouring products called “rastiks” which originated in the Orient (the Middle East and Near Asia). The green shells of the walnut (Juglans cinerea, nigra and regia) have been used as a material to colour the hair brown. The main active ingredient is juglone (5-hydroxy-1, 4-naphthoquinone) but a significant quantity of pyrogallol is also thought to contribute to the colouring effect. Pyrogallol was first identified and isolated in 18321 by Bracconot and was probably the first synthetic organic dye to be used to colour human hair. Used on its own it is a “progressive” dye as the colour builds with time. This highlights the fact that many naturally derived hair dyes are not necessarily inert substances and will either react with oxygen to produce a colour (as with pyrogallol) or may react with the hair keratin itself (as is probably the case with lawsone from henna).

Metals

The use of metals to colour the hair is also probably very ancient. The Romans and perhaps the Greeks are thought to have used lead combs dipped in vinegar (acetic acid) to give a progressive darkening effect. This technology (lead acetate) can still be found outside the EU in some products mainly intended for men (in the EU, the use of lead is banned in cosmetics). At the time of writing, for some products of this type bismuth has been substituted for lead. These products are thought to work by the deposition of sulphur compounds of lead within the hair shaft and are also sometimes known as “hair restorers”. An early recipe from Aetius7 suggested using a product made by boiling a solution of iron and lead in vinegar until one third remained. Many other metals have been used to colour the hair including iron (probably both ferrous and ferric), copper, nickel, manganese, cobalt and silver. Of these metals only silver (as the nitrate) is still allowed for use (specifically as number 48 in Annex 3 of the EU Cosmetics Directive) in the EU but to colour eyelashes and eyebrows only. Most metals have now been dropped for use in hair colouring cosmetics for a number of good safety and performance related issues. The majority of hair colouring recipes involving metals also utilise vinegar or “old wine”. This is logical as it is usually necessary to dissolve the metals in acidic media. Hence many old products were heated in iron, lead or copper vessels. In the majority of cases, plant-derived materials were added to the metal ion solutions as these mixtures tended to give much better performing products.

Interaction

It is common practice to use certain metal ions as a “mordant” to pre-treat textile fibres to ensure a greater dye uptake and retention in the fibre. In this type of procedure the positively charged metal ion would attract itself within the fibre and a subsequently applied solution of negatively charged dye would interact to form an insoluble coloured complex which would be “trapped” within the fibre. It is possible to repeat this process on human heads (although not at the higher temperatures which may be used on textiles). However, it is not always clear that this type of mordanting process is occurring when metal ions are used in conjunction with plant derived (organic) materials. A recipe for a rastik included roasting nutgalls (a source of pyrogallol) together with copper and iron filings with a small amount of oil in a copper vessel. The roasted mass was ground into a paste with water and applied to the hair being left for several hours1 and produced a permanent black colour on the hair. It would appear that this is more than just a simple case of “mordanting” and that it is likely that some chemical reactions also occur either in the product or on the hair. A later development of the rastik involved a two-part liquid product instead of starting with a powder. For instance, one bottle might contain copper sulphate and could contain ammonia while the other contained potassium ferrocyanide. This second part could also contain a hydrosulphide or pyrogallol as the “developer”.1 It appears that an improvement on this system was offered by Schueller in 1907 where the metal salts (copper and iron) were contained in one bottle with pyrogallol with a reducing agent such as sodium sulphite to prevent a reaction taking place. Subsequently, the colour was formed in a progressive fashion through aerial oxidation.

Compound hennas
It is likely that the term “compound hennas” came into use around 1914 when both Broux and Schueller of Paris started to sell a line of products based on henna but giving a wide shade range extending beyond red/orange. These products are similar to the systems already described but utilised a wider range of phenolic materials such as aminophenol, tannins and hematoxylin and a range of metal ions with sodium thiosulphate as the usual reducing agent.

Synthetic ‘oxidation’ dyes
Synthetic “oxidation” dyes are capable of colouring the hair permanently so that the colour is not washed out or lost by fading until the hair grows out (usually in 4 to 6 weeks). These products are based on the use of diaminobenzene compounds. It is believed that the first of the amino based dyes to be used on the hair was a diaminobenzene (phenylenediamine). Diaminobenzene can exist in three isomeric forms and the first to be discovered in 1854 by A. W. Hofmann was the meta compound. By 1872 all three isomers had been identified and the use of 1, 4-diaminobenzene (ppd or “para” as it became known to hairdressers) as a dye for hair, fur and feathers was patented in 1883.1 A period of rapid discovery and patenting of new compounds followed including ortho and para-aminophenol (opd and pap) as well a para-toluene diamine (ptd). The initial approach was first to treat the hair with an alkaline solution of the dye (really a dye precursor) and then to treat with a solution of an oxidising agent to “develop” the colour in the hair. The best results were eventually found to be obtained when ammonia was used as the alkali and hydrogen peroxide (discovered earlier in the 19th Century) as the oxidising agent. Ppd was popular as it was capable of producing a very natural looking black colour. All these compounds are known often by the term “primary intermediates”. The commercial development of products using these synthetic dyes started in the late 18th Century. The first standardised product (called Inecto – a brand name that can still be found today) was introduced in 1910 by Gaston Boudou with the assistance of Emile Rousseau and Raimond Sabouraud. In 1917, Boudou increased his range of shades from 8 to 18 and introduced a numbering system of 1 (black) to 9 (lightest blonde) with fractions to indicate colour modifications. This is still the basis of the shade description number used today. During the first quarter of the 20th Century the introduction of additional aromatic species (now known as “couplers”) to modify the colours that could be obtained was introduced i.e. by using an ortho or para diamine or aminophenol. These are generally meta substituted aromatic species such as resorcinol (1, 3-dihydroxybenzene, meta-phenylenediamine and metaaminophenol). These materials were quite probably utilised in the products bought by Lawrence Gelb in Paris in the early 1930s. Clairol’s early colour products contained a colorant and a developer in the form of solid tablets which needed to be added just before use. However, this product was incapable of lightening the hair which needed an additional pre-lightening process.6 During the 1940s, products were developed that used a liquid developer containing hydrogen peroxide which, in conjunction with a colorant containing ammonia, were capable of lightening the hair at the same time as colouring it. Hair colouring products, since the start of the 20th Century, had been sold mainly to hairdressers for “professional” use. However, during the mid-1950s, products for sale direct to the consumer were developed and marketed. The Clairol entry into this market was called Miss Clairol and used the famous advertising line of “Does she or doesn’t she?” Since the early 1970s, the toxicology and effects on humans of hair dyes has come under intense scrutiny making, perhaps, these dyes the most studied of any cosmetic product. This has led to the banning of a number of hair dyes and dye precursors. This has happened to a greater extent in the EU than the US and regulation in the two areas has been gradually drifting apart. Further advances have been made in permanent hair colouring products since the 1950s and these will be covered in more detail in a later article which will deal with the technology of the products up to the 21st Century.

Synthetic ‘direct’ dyes
Whereas oxidative hair colorants rely on uncoloured dye precursors which form a coloured pigment in situ within the hair it is possible to colour the hair with preformed dyes. A range of different hair dyes of this type have been developed and the first commercial products were launched in the 1960s as “semipermanent” hair colorants. These products required no ammonia and no oxidising agent and were initially based on unreactive derivatives of the oxidation dyes such as 2-nitro paraphenylenediamine. These products could be made to last from 1 to perhaps 8 washes by changing the nature of the dye materials.

Hair lightening
The Romans, it has been claimed, were the first to lighten their hair – wishing to copy the blond-haired slaves from the Northern Germanic areas. It has been suggested that potassium soap, made from goat fat and wood ash, was used for this purpose rather than for cleaning. The practice of coating the hair with something alkaline and then exposing it to sunlight has occurred at different times which, as well as lightening, will do some damage to the hair. The most satisfactory bleaching agent for the hair found so far is hydrogen peroxide which was discovered in 1818 by a French chemist called Thenard. The effect on hair was demonstrated at the Paris Exposition of 1867. The promoters were Thiellay of London and Hugo of Paris who used a 3% solution of hydrogen peroxide with the trade name “eau de fontaine de jouvence golden”. During the early 20th Century, solid forms of peroxide were developed (e.g. carbamide urea or sodium perborate) which are compounds which release hydrogen peroxide on contact with water. Hydrogen peroxide on its own is not a particularly good decoloriser for hair and its action can be enhanced by the addition of alkali (which also makes it decompose quite rapidly). Ammonia has been found to be most useful in this respect as it appears to have a specific action on the melanin granule. Ammonia and hydrogen peroxide are only capable of lightening the hair by perhaps 2 to 3 levels and to achieve greater degrees of lightening (and damage) other oxidising agents have been added to the mixture e.g. ammonium or potassium persulphate.

Evolution of technology
As discussed by Redgrove,5 a competition existed in 1929 between hair colouring products based on synthetic “para” dyes and those containing metal ions and phenolic compounds e.g. pyrogallol. The toxicology and side effects of the para dyes resulted in legislation and in certain materials (ppd) being banned. However, the para dyes gave a better and more natural effect on the hair when compared with products containing metals which were often described as being “flat paint jobs”. It has later become clear that the safety of the metal ion/pyrogallol systems left much to be desired and the latter material is now banned for use in the EU. However, a major reason for the demise of the metal containing products was the rise of hair perming products using thioglycollate and an oxidising neutraliser. The combination of these products can lead to interesting colours not to mention severe hair damage with possible hair loss. Hair permanent waving and the “para” dye system were found to be much more compatible. 

 Acknowledgements
Much of this article is gleaned from the work of other people and reference to them has been made where appropriate in the text. However, special mention is required of colleagues from Clairol – Dr John Corbett (to whom thanks are due for illustrations), Dr Keith Brown, Dr James Anderson and Dr Steve Casperson – who contributed greatly to the current understanding of this area. Thanks are also due to Anthony C. Dweck for illustrations.

References
1 Wall F.E. Chapter 23, Bleaches, hair colorings and dye removers, in Cosmetic Science and Technology, Balsam M.S., and Sagarin E., editors. 1972. p 279. 2 Zviak C., in The Science of Hair Care, 1st Edition, Zviak C., editor. Marcel Dekker, 1986, ISBN 10 0-8247-7378-0. 3 Zviak C., Millequant J., in The Science of Hair Care, 2nd Edition, Boulillon C., Wilkinson J., editors. Taylor & Francis, 2005, ISBN 10 0- 8247-5969-9. 4 L’Oréal publication supplied through personal communication. 5 Redgrove S.H., Foan G. A. Blonde or Brunette? A complete account of the theory and practice of hair-dyeing in all its branches. William Heinemann Ltd, 1929. 6 50 Colorful Years: The Clairol Story, Clairol Inc. 1982. 7 Lascaratos J., Tsiamis C., Lascaratos G., Stravianeas G. The roots of cosmetic medicine: hair cosmetics in Byzantine times (AD 324 – 1453), International Journal Of Dermatology 2004, 43, 397- 4