Hair Dye Ingredients and Potential Health Risks from Exposure to Hair Dyeing

Abstract

Given the worldwide popularity of hair dyeing, there is an urgent need to understand the toxicities and risks associated with exposure to chemicals found in hair dye formulations. Hair dyes are categorized as oxidative and nonoxidative in terms of their chemical composition and ingredients. For several decades, the expert panel’s Cosmetic Ingredient Review (CIR) has assessed the safety of many of the chemicals used in hair dyes; however, a comprehensive review of hair dye ingredients and the risk of exposure to hair dyeing has not been documented. Herein, we review the safety of the various chemicals in oxidative and nonoxidative hair dyes, toxicities associated with hair dyeing, and the carcinogenic risks related to hair dyeing. While many compounds are considered safe for users at the concentrations in hair dyes, there are conflicting data about a large number of hair dye formulations. The CIR expert panel has ratified a number of coloring ingredients for hair dyes and banned a series of chemicals as carcinogenic to animals and unsafe for this application. The use of these chemicals as raw materials for producing hair dyes may result in the synthesis of other contaminants with potential toxicities and increased risk of carcinogenesis. It is an open question whether personal or occupational hair dyeing increases the risk of cancer; however, in specific subpopulations, a positive association between hair dye use and cancer occurrence has been reported. To address this question, a better understanding of the chemical and mechanistic basis of the reported toxicities of hair dye mixtures and individual hair dye ingredients is needed. It is anticipated that in-depth chemical and systems toxicology studies harnessing modern and emerging techniques can shed light on this public health concern in the future.

Considering the risk of a coloring shampoo with the function of gray hair cover cosmetology and skin barrier: A systematic review

“…A warning about 1,2,3‐THB, which is the toxicity of the hair dye, and a review of the usage amount was done. Controlling the amount of THB used is emerging as a very important issue even in coloring shampoos containing hair dye ingredients 2 . In another study by Kunz and his colleagues, focusing on ultraviolet (UV) filters used in sunscreens and UV stabilization of materials, benzophenone‐1 (BP1), benzophenone‐2 (BP2), 4,4‐dihydroxybenzophenone, 4‐hydroxybenzophenone, 2,4,4‐trihydroxy‐benzophenone, was found to have an effect on the estrogen receptor.…”

Bleaching powders, bleaching creams and other hair lightening preparations as sources for (airborne) allergic contact dermatitis and other health effects in hairdressers: Results of an empirical study

“…It must yet be assumed that these choices are made with the colour result for the client in mind rather than considering health protection. Moreover, the colour creams may contain contact allergens as well, 25 so that adequate skin protection by wearing gloves is always a necessity. This is not only of relevance for working with oxidative hair dyes, as addressed in this article, but also for non‐oxidative hair dye products, which have been addressed in a recent survey 26 …”

Polyphenols Coordinated with Cu (II) in an Aqueous System Build Ion-Channel Coatings on Hair Surfaces

“…Most commercial chemical dyes contain bleaching agents such as ammonia and peroxide [ 15 , 16 , 17 ]. During the hair-dyeing process, bleaching agents first damage the outermost cuticle layer of the hair and push chemical colors such as p-Phenylenediamin (PPD), o-Phenylenediamine (OPD), and m-Phenylenediamine (MPD) to enter the cortex layer [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. The bleaching agents fade the pigment melanin and further react with chemical colors, creating a new color and stocking inside the hair.…”