Peracid Oxidation of Human Hair

The qualitative observations of the Allworden reaction are produced by relatively large concentrations of chlorine or bromine water. Fair and Gupta [41] were the first to investigate the effect of chlorine water on hair, at the parts-per-million level, in an attempt to assess the effects of chlorine in swimming pools on hair. 

In this study, hair effects were measured by following changes in hair fiber friction. In general, the effect of chlorine was to increase the coefficient of fiber friction and to decrease the differential friction effect in hair. Changes in hair friction were observed even at parts-per-million levels of chlorine. Effects increased with the number of treatments and with decreasing pH from 8 to 2. 

The actual oxidizing species present depends on pH and is either chlorine or hypochlorous acid (HOCl). Apparently, the hypochlorous acid is the more active species on hair given that degradation is greater at lower pH. Although the chemistry of these interactions was not examined, one would expect disulfide bond cleavage and peptide bond fission similar to the effects shown for the reaction of chlorine and wool fiber [42]. 

Peracetic acid was the first peracid studied extensively in keratin fiber research. This highly reactive species ultimately became the vehicle used in the well-known keratose method by Alexander and Earland used to isolate keratose fractions of keratin fibers and described here in Chapter 1. 

After multiple treatments with m-diperisophthalic acid, when bundles of hbers or tresses are allowed to dry, the hbers actually appear glued together, reminiscent of the combined photochemical plus peroxide bleach treatment 

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