Temporary hair dyes

Temporary hair dye products usually are formulated at a neutral or slightly acidic pH. Besides the dyes, the formulations may contain a small amount of a quaternary amine to neutralize the negative charge on the dyes, a fragrance, a small amount of a solvent or surfactant to solubilize the fragrance, and a preservative (Table 6). 

Hair dyeing includes the use of permanent, semipermanent, and temporary dyes. A permanent dye lasts through any number of washings as well as permanent waving. A semipermanent dye is removed after two to ten washings, and a temporary dye is largely eliminated after one washing. 

Hair dyes are of three kinds temporary, semi-permanent, and permanent. The first kind are easily washed out of the hair, the second will survive several washings but eventually fade, and the third are locked fast within the hair shaft and disappear only as the hair grows... 

A survey of 608 Connecticut women with breast cancer and 609 women who were free of the disease, was carried out under the auspices of Yale School of Public Health with collaboration from the European Institute of Oncology in Italy, McGill University in Canada, and the US National Cancer Institute. This weighty team of international medics found no evidence that those who used hair dyes of either the temporary or permanent kind were in any way increasing their risk of having breast cancer, and they published their results in the European Journal of Cancer in August 2002. In 2003 another study was undertaken by the world-famous Karolinska Institute of Sweden and specifically looked at the incidence of all types of cancer in Swedish hairdressers, the group that was expected to be most at risk. 

Temporary hair dye products frequently contain thickeners, a surfactant, sometimes a hair-setting polymer, and a buffer or acid such as tartaric, acetic, or citric to provide an acid medium for application of the dyes to the hair. To make the hair rinses described in Table 6-11, first hydrate the hydroxyethylcellulose (0.7 g) with 49 g of water by stirring, then add the neodol and the nonoxynol. Add the remaining water followed by the buffer, and then slowly dissolve the dyes in the product with stirring. Finally, add the cetrimonium chloride and stir until it is completely dissolved. 

Both Corbett [5] and Kirkland [60] have summarized the results of several common hair dye ingredients in in vitro mutation tests, in dominant lethal animal testing, and in epidemiological studies. One of these testing programs consists of a Cosmetics, Toiletries and Fragrance Association (CTFA) study involving more than 35 oxidation dye components and 34 textile dyes used in temporary hair color products. From this work and other studies, the FDA has determined (in October 1979) that all hair dye prod-... 

Hair coloring preparations are classified into four types temporary dye, metallic (progressive) dye, ionic (acidic and basic) dye, and permanent (oxidative) dye. The oxidative dye is the most popular hair dye because of its color durability and easy application. Oxidative dyes are usually composed of dye compounds (A) solution and a hydrogen peroxide (B) solution. Both solutions are creamy. The A solution also contains strong alkaline ammonia to open hair cuticles. Dye components polymerize into indophe-nol-like trimers, etc., in the presence of hydrogen peroxide, primarily in the cortex of the hair. Hairs 3 cm long dyed by oxidative dyes of 34 brands are dissolved in the solution of methanol plus 3 mol 1 ... 

Semipermanent dyes are formulations that dye the hair without the use of hydrogen peroxide, to a colour that only persists for 4-6 shampooings. Temporary hair dyes or colour rinses aim to provide colour that is removed after the first shampooing process. 

Several studies have suggested an increased risk of blabber cancer among hairdressers, who are occupationally exposed to hair dyes. There has also been concern about a possible increased risk of bladder cancer among users of hair dyes. However, the association between personal hair dye use and bladder cancer risk remains inconclusive. This study examines the association between personal use of permanent and temporary hair dyes and bladder cancer risk in a population-based case-control study involving 1.385 cases (n=246 women) and 4754 controls (n=2.587 women) [29 ]. 

Another important formulation in the cosmetic industry is that used for hair dyeing. Three main steps may be involved in this process bleaching, bleaching and coloring combined as well as dyeing with artificial colors. Hair dyes can be classified into several categories permanent or oxidative dyes, semipermanent dyes and temporary... 

According to how long-lasting they are, hair-dye prodncts may be classified into three gronps temporary, semi-permanent, and permanent hair colonrs. The two formers are based into a non-oxidation mechanism, whereas the last is based mainly on oxidation reactions although other chemicals which impart progressive permanent hair colonr do not follow this mechanism. They are discnssed below. 

Modem hair colorants can be divided into temporary, semipermanent, and permanent systems. These categories are characterized by the durabiUty of the color imparted to the hair, the type of dye employed, and the method of apphcation (see Dyes and dye intermediates). 

Temporary hair colorants are removed from the hair by a single shampoo. Temporary hair colorants usually employ certified dyes that have tittle affinity for hair (see Table 9). They are incorporated into aqueous solutions, shampoos, or hair-setting products. 

In the United States the use of coal-tar dyes ia eye makeup is geaerally prohibited. The use of permanent and temporary hair colorants (Tables 16 and 17) and of organic dyes and their lakes is precluded. As a result, only iasoluble inorganic pigments can be used (Table 9). The sensitivity of the eye... 

With direct dyes (see Section 3.3), as opposed to oxidation dyes, the actual dye (and not its precursor) is applied to the hair. It imparts a semipermanent or temporary color that lasts for a variable time. Lightening is not possible. 

The dyeing process provides for temporary, semipermanent (direct dyes), and oxidation-type reactions (semipermanent or permanent colors). It may involve absorption or adsorption (electrostatic) of the colorant into/to the hair structure, bleaching or otherwise masking the natural melanin col-... 

Henna. Henna is the oldest and most widely used vegetable dye utilized in hair coloring. A temporary chestnut color is produced in blond or auburn hair by applying a paste of henna flowers and leaves ground in hot water immediately before use. (The dye is unstable in aqueous solution.) The addition of indigo achieves darker blue-black shades extracts of walnut shell or logwood enhance brown coloration. 

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