Lead acetate, hair coloring

Metallic Dyes. MetaUic dyes are among the older hair color materials known. Commercial products are based on a 1% solution of lead acetate in an aqueous, slightly acidic, alcohoHc medium. Precipitated sulfur appears to be essential. The convenience aspect is stressed by the leave-in appHcation method. Actually, the color development is so slow, taking about a week to ten days, that there is no alternative to this technique. Daily appHcation is needed at first. 

Lead acetate can be used only for coloring scalp hair at a level not to exceed 0.6%, as lead, weight/volume of the product. The regulations provide specific restrictions (including label specifications) that lead acetate must not be used to color mustaches, eyelashes, eyebrows, or hair on parts of the body other than the scalp. 

Permanent coloration can also be achieved by exposing hair to certain metals copper, silver, and especially lead salts. Preparations containing aqueous solutions of lead acetate may include a source of sulfur, usually thiosulfate, which may react with cystine in the hair to produce some cysteine or may react directiy with the metal ion to form dark metallic sulfides. Preparations of this type, which darken hair gradually, are not universally considered safe. 

In the home, you or your children may be exposed to lead if you take some types of home remedy medicines that contain lead compounds. Lead compounds are in some non-Westem cosmetics, such as surma and kohl. Some types of hair colorants and dyes contain lead acetate. Read the labels on hair coloring products, use them with caution, and keep them away from children. 

Some types of paints and pigments that are used as facial make-up or hair coloring contain lead. Cosmetics that contain lead include surma and kohl, which are popular in certain Asian countries. Read the labels on hair coloring products, and keep hair dyes that contain lead acetate away from children. Do not allow children to touch hair that has been colored with lead-containing dyes or any surfaces that have come into contact with these dyes because lead compounds can rub off onto their hands and be transferred to their mouths. 

Some hair-coloring products contain the water-soluble compound lead (II) acetate, Pb(CH3COO)2. When the coloring product is applied to the hair, a chemical reaction occurs between the Pb2+ ion and the sulfur atoms in cysteine and methionine incorporated in amino acids in hair proteins. The insoluble black product lead(II) sulfide forms. 

Melanin compounds may appear brown, black, or red. The type of melanin determines hair color, and the density of melanin granules determines the shade. Dark shades of dyed hair contain higher concentrations of dyes. Most hair colors are combinations of organic compounds chosen to produce particular shades. Resorcinol produces a yellow color aminohydroxy-toluene produces a redder hair, and nitrophenylenediamine dye results in very red hair. Graded dyes favored by men often contain lead acetate. The lead ions penetrate into hair and form lead sulfide (PbS), a dark-colored compound. 

Permanent hair colors contain an oxidizer (usually 6% hydrogen peroxide) and a dye intermediate (p-phenylenediamine, resorcinol, aminophenols along with water, ammonia, glycerin, isopropanol, and propylene glycol). Semipermanent hair colors contain propylene glycol, isopropanol, fatty acids, fragrance, alkanolamines, and dyes. Some Grecian hair formulations contain lead in the form of lead acetate. 

Salts of several metals including lead, silver, bismuth, cobalt, copper, iron, and mercury have been used in the past for dyeing hair [45]. Among these metallic dyes, lead dyes are the only ones in commercial use today. Lead dyes contain lead acetate and sulfur [46] (Table 6-12) and react with hair to darken slowly, presumably forming lead-sulfur complexes in the cuticle layers. These products are popular among men because of the slow gradual buildup of color however, shades are limited, and the dye can react if treated subsequently with bleaches, permanent waves, and even with certain other hair dyes [16],... 

For the identification of wool and other animal hairs, one can use the so-called plumbate reaction formation of a black color resulting from the presence of sulfur in a water/alcohol solution of lead acetate heated to 80 - 90 °C. 

Ammonium acetate Ammonium persulfate HC yellow 4 Henna (Lawsonia inermis) extract Lead oxide, yellow colorant, hair dyes... 

Progressive hair dye products contain lead in the form of lead acetate (FDA 2011b). These dyes are applied over a period of time to achieve a gradual hair color change. People using such dyes have been monitored and no increase in blood lead level has been found from such use. However, a warning is required on these products that states they are for external use only, should not be applied in areas where there are scalp abrasions, and the product should not be allowed to get into eyes. 

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